Exploring the Contribution of Pharmacists in Addressing the Opioid Crisis through Naloxone Prescriptions and Pharmacist-Led Interventions

The opioid epidemic in the United States continues to take the lives of many individuals, with overdoses continuing to rise every year. Naloxone is an opioid antagonist that is efficacious in temporarily reversing opioid overdoses. Pharmacists play an important role in the accessibility and education of naloxone in both the community and health system settings. Recent efforts, such as co-dispensing naloxone with opioid prescriptions, naloxone training programs, and approval of naloxone to be over-the-counter, have been implemented in hopes to better control the opioid epidemic. Despite the efforts to make naloxone more accessible, there are still some barriers to overcome such as lack of training, cost, stigma, and patient refusal. This review aims to explore the contributions pharmacists have made thus far and define the barriers that still have to be resolved.

Analgesic effects of receptin, a chemically modified cobratoxin from Thai-land cobra venom

Objective To investigate the analgesia induced by receptin （REC）, a chemically modified cobratoxin （CTX, a long-chain postsynaptic α-neurotoxin from Thailand cobra venom）, and the effects of atropine and naloxone on antinociceptive activity of REC in rodent pain models. Methods REC was administered intraperitoneally （5 mg/kg, 7.07 mg/kg, or 10 mg/kg, i.p.） or intra-cerebral venticularly （62.5 μg/kg, i.c.v.）. The antinociceptive action was determined using the hotlate test, the acetic acid writhing test and tail flick assay in mice and rats. The involvement of cholinergic and the opioid peptidergic systems in REC-induced analgesia were examined by pretreatment of animals with atropine （Atr; 0.5 mg/kg, i.m. or 10 mg/kg, i.p.） or naloxone （Nal; 3 mg/kg, i.p.）. The effect of REC on motor activity was tested using the Animex test in mice. Results REC （5 mg/kg, 7.07 mg/kg or 10 mg/kg, i.p.） exhibited a dose-dependent analgesic action in mice as determined with hot-plate test and acetic acid writhing test. The significant analgesia of REC was seen 2 h to 3 h after its administration. In the rat-tail flick assay, the administration of REC at 62.5 μg/kg （1/160 of systemic dose; i.c.v.）produced marked analgesic effects. Atropine at 0.5 mg/kg （i.m.）, 10 mg/kg （i.p.） or naloxone at 3 mg/kg （i.p.） failed to block the analgesic effects of REC. REC at the highest effective dose of 10 mg/kg did not change the spontaneous mobility of mice. Conclusion These results demonstrate that REC has analgesic effect. This activity appears to be mediated through the peripheral nervous system though central nervous system may contribute to REC＇s analgesic effects. The central cholinergic system and opioid peptidergic system appear not to be involved in the antinociceptive action of REC.

Pharmacokinetics and Absolute Bioavailability of the Sublingual Naloxone Hydrochloride Tablet in Dogs

The pharmacokinetics and absolute bioavailability of the sublingual naloxone tablet were studied with HPLC-electrochemical detection. Eight male dogs received single 5 mg dose of naloxone intravenously, the plasma concentration-time curves could be fitted to two-compartment open model, with 12.0 min of t1/2( , 143.4 min of t1/2( and 7.92 mg(min/L of AUC. The same eight dogs received 5 mg dose of the sublingual naloxone tablet after an interval of a week. The main pharmacokinetic parameters were: t1/2ka = 11.0 min, t1/2( = 15.4 min, t1/2( = 164.1 min, Tmax = 27.7 min, Cmax = 34.2 ng / ml, and AUC = 6.79 mg(min / L, respectively. The plasma concentration-time curves were fitted to the first order absorption two-compartment open model also. The mean absolute bioavailability of the sublingual naloxone tablet was 86.8 ( 10.9%. No statistically significant differences were found with t1/2(, t1/2(, ( and ( between the two routes of administration. These results indicated that the course of disposition for naloxone in dogs was similar for the two routes of administration, and the absolute bioavailability of the sublingual naloxone tablet was high. Thus satisfactory clinical effects could be expected.

Naloxone or Vagotomy Does Not Influence Centrally Octreotide-induced Inhibition of Gastric Acid Secretion in Rats

Summary： To investigate the effect of preceding naloxone injection into the third cerebroventricle or acute subdiaphragmatic vagotomy on the gastric acid secretion inhibited by the somatostatin analogue octreotide given by intracerebroventricular （icv） injection. The third ventricles were cannulated in male Wistar rats anesthetized with sodium pentobarbital. One week later, acute gastric lumen perfusion was carried out. The gastric perfusion samples were collected every 10 min and were titrated by 0.01 mol/L NaOH to neuter. On the basis of subcutaneous injection of pentagastrin （G-5, 160 g/kg）, icv injection of physiological saline （group A, n=20）, icv injection of octreotide （0.05 μ g） （group B, n=20）, icv injection of naloxone （2.5 μ g）＋octreotide （0.05 μg） （group C, n=20）, acute subdiaphragmatic vagotomy＋ icv injection of physiological saline （group D, n=20）, or acute subdia- phragrnatic vagotomy＋icv injection of octreotide （0.05 μg） （group E, n=20） were conducted. Before and after icv injection, 1-h total acid output （TAO） was determined and compared. The experimental data were expressed in change rate （%） of TAO. The change rates （%） of TAO were 4.60 % in group A, -20.35 % in group B, - 18.06 % in group C, 5.01% in group D and -21.59 % in group E, respectively. Comparison of group B or C versus group A showed that P〈0.01 and comparison between the group E versus group D showed that P〈0.01. Whereas the differences between group C and group B, group E and group B were not statistically significant （P〉0.05 for all）. The results indicate that the central inhibition of gastric acid secretion by octreotide may not be mediated by the endogenous opi- ate substance or its receptor and the peripheral pathway for icv injection of octreotide to suppress gastric acid secretion is via extra-vagus route.

Efficacy and safety of controlled-release oxycodone/naloxone versus controlled-release oxycodone in Korean patients with cancer-related pain: a randomized controlled trial

Background: Controlled-release oxycodone/naloxone(OXN-CR) maintains the effect of opioid-induced analgesia through oxycodone while reducing the occurrence rate of opioid-induced constipation through naloxone. The present study was designed to assess the non-inferiority of OXN-CR to controlled-release oxycodone(OX-CR) for the control of cancer-related pain in Korean patients.Methods: In this randomized, open-labeled, parallel-group, phase IV study, we enrolled patients aged 20 years or older with moderate to severe cancer-related pain [numeric rating scale(NRS) pain score ≥4] from seven Korean oncology/hematology centers. Patients in the intention-to-treat(ITT) population were randomized(1:1) to OXNCR or OX-CR groups. OXN-CR was administered starting at 20 mg/10 mg per day and up-titrated to a maximum of80 mg/40 mg per day for 4 weeks, and OX-CR was administered starting at 20 mg/day and up-titrated to a maximum of 80 mg/day for 4 weeks.The primary efficacy endpoint was the change in NRS pain score from baseline to week4, with non-inferiority margin of-1.5. Secondary endpoints included analgesic rescue medication intake, patientreported change in bowel habits, laxative intake, quality of life(QoL), and safety assessments.Results: Of the ITT population comprising 128 patients, 7 with missing primary efficacy data and 4 who violated the eligibility criteria were excluded from the efficacy analysis. At week 4, the mean change in NRS pain scores was not significantly different between the OXN-CR group(n = 58) and the OX-CR group(n = 59)(-1.586 vs.-1.559,P = 0.948). The lower limit of the one-sided 95% confidence interval(-0.776 to 0.830) for the difference exceeded the non-inferiority margin(P < 0.001). The OXN-CR and OX-CR groups did not differ significantly in terms of analgesic rescue medication intake, change in bowel habits, laxative intake, QoL, and safety assessments.Conclusions: OXN-CR was non-inferior to OX-CR in terms of pain reduction after 4 weeks of treatment and had a similar safety profile. Studies in larger populations of Korean patients with cancer-related pain are needed to further investigate the effectiveness of OXN-CR for long-term pain control and constipation alleviation.Trial registration ClinicalTrials.gov NCT01313780, registered March 8。

A short-chain α-neurotoxin from Naja naja atra produces potent cholinergic-dependent analgesia

Objective To investigate the analgesia induced by cobrotoxin （CT） from venom of Naja naja atra, and the effects of atropine and naloxone on the antinociceptive activity of CT in rodent pain models. Methods CT was administered intraperitoneally （33.3, 50, 75 μg/kg）, intra-cerebral venticularly （2.4 μg/kg） or microinjected into periaqueductal gray （PAG, 1.2 μg/kg）. The antinociceptive action was tested using the hot-plate test and the acetic acid writhing test in mice and rats. The involvement of cholinergic system and the opioid system in CT-induced analgesia was examined by pretreatment of animals with atropine （0.5 mg/kg, im or 10 mg/kg, ip） or naloxone （3 mg/kg, ip）. The effect of CT on motor activity was tested using the Animex test. Results CT （33.3, 50 and 75 μg/kg, ip） exhibited a dosedependent analgesic action in mice as determined with hot-plate test and acetic acid writhing test. In the mouse acetic acid writhing test, the intra-cerebral ventricle administration of CT 2.4 μg/kg （1/23th of a systemic dose） produced marked analgesic effects. Microinjection of CT 1.2 μg/kg （1/46th of systemic dose） into the PAG also elicited a robust analgesic action in the hot-plate test in rats. Atropine at 0.5 mg/kg （ira） or naloxone at 3 mg/kg （ip） failed to block the analgesic effects of CT, but atropine at 10 mg/kg （ip） did antagonize the analgesia mediated by CT in the mouse acetic acid writhing test. At the highest effective dose of antinociception （75 μg/kg）, CT did not change the spontaneous mobility of mice. Conclusion These results suggest that CT from Naja naja atra venom has analgesic effects. Central nervous system may be involved in CT＇ analgesic effects and the PAG may be the primary central site where CT exerts its effects. The central cholinergic system but not opioid system appears to be involved in the antinociceptive action of CT.

EFFECTS OF NALOXONE ON THE CHANGES OF PAIN THRESHOLD AND CONTENTS OF MONOAMINE NEUROTRANSMITTERS IN RAT BRAIN INDUCED BY EA

5-HT content in medulla oblongata plus pons and DA level in brain stem obviously increased,while NA concentration in telencephalon markedly decreased in EAA.A previous injection ofnaloxone,a blocker of opiate receptor,could partially inhibit the EAA,abolish the effects ofEA’s increasing the 5-HT content in the medulla oblongata plus pons and the DA level in thebrain stem,and decrease the NA level in the diencephalon after EA.These results indicate thatEA may mediate the metabolism of the central monoamine neurotransmitters partially via opiatereceptor to exert its analgesic effect.

Effect of Morphine and Naloxone on Release of the Excitatory Amino Acids of Spinal Astrocytes Induced by TNF-α

The effect of morphine and naloxone on release of the excitatory amino acids (EAAs) of spinal astrocytes induced by TNF-α was studied. Astrocytes were purified from 2- to 3-day old SD rats and divided into 8 groups: group 1 (without any stimulatants); group 2 (10 ng/ml TNF-α); group3 (10 ng/ml TNF-α+0.5 μmol/L morphine); group 4 (10 ng/ml TNF-α+1.0 μmol/L morphine); group 5 (10 ng/ml TNF-α+2.0 μmol/L morphine); group 6 (10 ng/ml TNF-α+0.5 μmol/L naloxone); group 7 (10 ng/ml TNF-α+1.0 μmol/L naloxone); group 8 (10 ng/ml TNF-α+2.0 μmol/L naloxone). In group 2, 3, 4 and 5, 0, 0.5, 1.0 or 2.0 μmol/L morphine was added to the cells cultured with serum-free Neurobasal/B27 medium containing 10 ng/ml TNF-α respectively, while in group 6, 7 and 8, 0.5, 1.0 or 2.0 μmol/L naloxone was added respectively to the cells cultured with serum-free Neurobasal/B27 medium containing 10 ng/ml TNF-α. After 30 min incubation, high-pressure liquid chromatography (HPLC) was used to measure the levels of EAAs in all cultured cells. The results showed the level of EAAs in group 2 was significant higher than in group 1 (P<0.01). As compared with group 2, the levels of EAAs in group 3, 4 and 5 were decreased with the difference being significant between group 5 and group 2 (P<0.01) or between group 4 and group 2 (P<0.05). The levels of EAAs in group 6, 7 and group 8 was significantly lower than in group 2 (P<0.05 or P<0.01). It was concluded that TNF-α could promote the release of glutamate and aspartate from astrocytes, and morphine and naloxone might reduce the release of EAAs in cultured spinal astrocytes induced by TNF-α.

Sodium alginate and naloxone loaded macrophage-derived nanovesicles for the treatment of spinal cord injury

Spinal cord injury(SCI)causes Ca^(2+) overload,which can lead to inflammation and neuronal apoptosis.In this study,we prepared a nanovesicle derived from macrophage membrane(MVs),which encapsulated sodium alginate(SA)and naloxone(NAL)to inhibit inflammation and protect neurons by reducing the free Ca^(2+) concentration at the SCI site.Based on the transmission electron microscopy(TEM)image,the encapsulated sample(NAL–SA–MVs)had a particle size of approximately 134±11 nm and exhibited a sustained release effect.The encapsulation rate of NAL and SA was 82.07%±3.27%and 72.13%±2.61%in NAL–SA–MVs,respectively.Targeting tests showed that the NAL–SA–MVs could accumulate in large quantities and enhance the concentration of SA and NAL at the lesion sites.In vivo and in vitro studies indicated that the NAL–SA–MVs could decrease the concentration of free Ca^(2+),which should further alleviate the inflammatory response and neuronal apoptosis.Anti-inflammation results demonstrated that the NAL–SA–MVs could reduce the pro-inflammation factors(iNOS,TNF-α,IL-1β,IL-6)and increase the expression of antiinflammation factors(IL-10)at the cell and animal level.Concurrently,fluorescence,flow cytometry and western blot characterization showed that the apoptotic condition of the neurons was significantly inhibited.In addition,the motor function of C57 mice were significantly improved after NAL–SA–MVs treatment.In conclusion,it is suggested that the NAL–SA–MVs has tremendous potential in the treatment of SCI.

Interventional effect of scorpion venom from Buthus martensii Karsch in Liaoning on somatic pain

BACKGROUND： Scorpion venom from Buthus martensii Karsch is a kind of protein toxin secreted by scorpion tail. According to records of Pen-ts ＇ao Kan-mu, the dried scorpion＇s body and tail are used as medicine, which mainly treating rheumatism numbness, pain and convulsion. Some researches consider that scorpion toxin is the main pharmacological active component of the dried scorpion, and it has 4 times stronger analgesic effect on somatic pain than morphine. OBJECTIVE： To observe the interventional effect of scorpion venom of Buthus martensii Karsch analgesic active peptide on somatic pain. DESIGN： A randomized and controlled trial SETTING： Department of Physiology, Shenyang Medical College MATERIALS： Totally 80 Wistar rats （provided by Animal Center of Shenyang Medical College）, male and female in half, aged 3 to 4 months, weighed 250 to 350 g, were used in this trial. They were randomly divided into 4 groups： experimental group, control group, morphine group and naloxone group, with 20 in each group. Analgesia active peptide from buthus martensii karsch venom （provided by Biochemical Department of Shenyang Pharmaceutical University, 1 mL/dosage）, morphine （produced by Shanghai First Pharmaceutical Manufacturing Plant）, naloxone （opium acceptor inhibitor, American Sigma Corporation）, AT- AC-350 data-processing machine （Nihon Kohden Corporation）, X-Y recording instrument （Nihon Kohden Corporation）. METHODS： The experiment was conducted in the Department of Physiology, Shenyang Medical College from July 2003 to July 2005. ① After all the animals were anesthetized, common peroneal nerve is dissected and ligated at middle part. Posterior nucleus group of thalamus （PO） and the tail nuclear were oriented according to G. Paxino rat brain three-dimensional orientation atlas, Glass micro electrode was inserted into PO as guiding electrode, connected with ATAC-350 data-processing machine and X-Y recording instrument, to record the unit evoked potential of PO, taking the evoked potential discharge of the common peroneal nerve of PO as the somatic pain index.② Single square-wave stimulation of intensity 17-19 volt, wave wide 0.2 ms, time delay 20 ms was exerted on common peroneal nerve. The time interval was 5 minutes. X-Y recording instrument was used to draw the graph. 0,002 mg scorpion venom analgesic active peptide was injected into the rats of the experimental group; 0.002 mg normal saline was injected into the rats of the control group through caudate nucleus; 0.002 mg morphine was injected into the rats of morphine group through caudate nucleus; 1.0 mg/kg naloxone was intraperitoneally into the rats of naloxone group, then 0.002 mg scorpion venom was injected into the rats of control group through caudate nucleus.Changes of evoked potential of PO of 3 groups were observed. ③After experiment, 1 μA direct current was given to the guiding electrode and micro electrode , and it lasted for 5 minutes. Pontamine sky blue was used to label the peak of electrode by electrophoresis. Brain tissue was soaked in formalin for 1 week then sliced into 1.0 to 1.5 mm sections. Electrode was orientated according to blue spots. Compared with G . Parino rat brain three-dimensional orientation atlas, we confirmed if the electrode orientation is consistent with PO orientation of G. Parino rat brain three-dimensional orientation atlas. MAIN OUTCOME MEASURES ： Changes of the evoked potential of PO in each group RESULTS： Totally 80 Wistar rats were enrolled in this experiment. Four rats in the experimental group and two in the morphine group died of overdose of anesthesia, and finally 74 rats entered the stage of result analysis. The inhibitory action time of evoked potential of PO has no statistical difference in between experiment group and morphine group （P 〉 0.05）. The whole inhibitory action time, timeof initiate recovery and time of complete recovery of PO of experiment group were longer than those in the morphine group [（45±0.7）, （50±9.2）, （65±8.1）：（35±7.8）. （40±8.9）. （50±7.6） min .P 〈 0.05].The change of evoked potential of PO was not obviously in the control group and naloxone group （P 〉 0.05）, and the above-mentioned 4 indexes were nearly 0. CONCLUSION： Scorpion venom possesses obviously inhibitory effect on somatic pain, and its inhibitory effect is stronger than that of the same dosage and concentration of morphine. Scorpion venom exerts analgesic effect on somatic pain through opium acceptor.

Opioid/naloxone prolonged release combinations for opioid induced constipation

I read with great interest the recent article by Chen et al in a recent issue of your esteemed journal.The article is highly thought provoking.One emerging therapeutic alternative for opioid induced constipation is the emergence of opioid/naloxone prolonged release combinations.For instance,naloxone when administered in a 1:2 ratio with oxycodone reverses the inhibitory effect of oxycodone on the gastrointestinal tract.The advantage of oxycodone/naloxone prolonged release(OXN) is that while its anti-nociceptive efficacy is equivalent to that of oxycodone prolonged release(OXC),it significantly decreases the "Bowel Function Index" thereby ameliorating symptoms of opioid induced constipation to a large extent.Schutter et al in a recent study have reported a decrease in the bowel function index from 38.2 to 15.1.Similarly,L wenstein et al in another recent study have reported that following a month of therapy,complete spontaneous bowel movements per week is increased from one in OXC therapy to three in OXN therapy.

Inhibitory effects of HS014 on glutamate release in astrocytes chronically treated with morphine

Previous studies have confirmed that the number of glial fibrillary acidic protein-positive cells significantly increases during morphine tolerance. However, morphine tolerance is reversed with melanocortin receptor antagonists, and analgesic action is enhanced accordingly. However, these mechanisms remain unclear. In the present study, following addition of morphine to Wistar rat spinal cord astrocytes, glutamate levels in the supematant significantly increased （P 〈 0.05）. At 30-120 minutes following addition of intervention agent to spinal cord astrocytes, naloxone significantly increased glutamate release in morphine-tolerant model cells （P 〈 0.05）, while melanocortin receptor antagonist HS014 decreased glutamate release （P 〈 0.05）. Additional naloxone and HS014 to astrocytes significantly decreased glutamate release compared with additional naloxone alone （P 〈 0.01）. Results from the present study demonstrated that glutamate release was increased in spinal cord astrocytes co-cultured with morphine. Naloxone increased glutamate release, and HS014 reduced glutamate release.

Optimal compatible doses and effects of ephedrine and naloxone on neural plasticity in cerebral ischemia/reperfusion rats

BACKGROUND： Ephedrine promotes neural plasticity in rats following cerebral ischemia/reperfusion injury. Ephedrine has been combined with naloxone in some studies, and it has been confirmed that their combination has synergistic effects on increasing neural plasticity following cerebral ischemia/reperfusion injury. OBJECTIVE： To investigate the effects of ephedrine combined with various doses of naloxone on neural plasticity and to find an optimal dose of naloxone in rats after cerebral ischemia/reperfusion injury by analyzing growth associated protein-43 （GAP-43）, synaptophysin and β-endorphin expression in the hippocampal CA3 area. DESIGN, TIME AND SETTING： This immunohistochemical, randomized, controlled, animal experiment was performed at the Chongqing Research Institute of Pediatrics, China from September 2007 to June 2008. MATERIALS： Ephedrine hydrochloride injection and naloxone hydrochloride injection were respectively purchased from Shandong Lvliang Pharmaceutical Factory, China and Sichuan Jingwei Pharmaceutical Co., Ltd., China. A total of 192 healthy adult Sprague Dawley rats were used to establish models of left middle cerebral artery occlusion using the suture occlusion method. METHODS： At 2 hours following cerebral ischemia, the rats were intraperitoneally injected with 1.5 mg/kg/d ephedrine （ephedrine group）, with 0.1, 0.2, or 0.3 mg/kg/d naloxone （low, moderate and high doses of naloxone groups）, with 1.5 mg/kg/d ephedrine ＋ 0.1, 0.2, or 0.3 mg/kg/d naloxone （ephedrine ＋ low, moderate and high doses of naloxone groups）, and with 0.5 mL saline （model group）, respectively. MAIN OUTCOME MEASURES： GAP-43, synaptophysin and β -endorphin expression were detected in the hippocampal CA3 area using immunohistochemistry 1-4 weeks after surgery. Sensorimotor integration in rats was assessed using the beam walking test. RESULTS： GAP-43 and synaptophysin expression was greater in the ephedrine group, and in the ephedrine ＋ moderate and high doses of naloxone groups compared with the model group. GAP-43 and synaptophysin expression was greatest in the ephedrine ＋ high dose of naloxone group at 2 and 3 weeks alter surgery. β -endorphin expression was significantly lower in the ephedrine group, and in the ephedrine ＋ moderate and high doses of naloxone groups compared with the model group （P 〈 0.05）. β -endorphin expression was persistently low in the ephedrine ＋ high dose of naloxone group. At 1-3 weeks after surgery, the beam walking test score was significantly higher in the ephedrine group and ephedrine ＋ various doses of naloxone groups than in the model group （P 〈 0.05）. The score was higher in the ephedrine ＋ moderate and high doses of naloxone groups than in the ephedrine group （P 〈 0.05）. Moreover, the score was increased as the dose of naloxone increased in the ephedrine ＋ various doses of naloxone groups. CONCLUSION： Ephedrine promotes GAP-43 and synaptophysin expression, inhibits /3 -endorphin expression in the hippocampal CA3 area, and improves motor function in rats following cerebral ischemia/reperfusion injury. Naloxone does not have the above-mentioned effects. During combined treatment with ephedrine and naloxone, however, the above-described effects are enhanced with an increased dose of naloxone. The combination of ephedrine （1.5 mg/kg/d） and naloxone （0.3 mg/kg/d） can produce optimal therapeutic efficacy in treatment of cerebral ischemic injury.

Effect of naloxone on level of plasma beta-endorphin in neonates with severe asphyxia

β-endorphin is the most actively endogenous substance of cerebral endorphin. When combined with opiate receptor specially, it manifests a strong morphine-like activity and can decrease sensitivity of central nervous system to carbon dioxide so as to inhibit breath. OBJECTIVE： To observe the changes of content of plasma β-endorphin in neonates with severe asphyxia after naloxone treatment in a large dosage. DESIGN： Randomized controlled observation. SETTINGS： Department of Pediatrics, Shenzhen Shajing People＇s Hospital; Center of Pediatrics, Guangzhou Zhujiang Hospital. PARTICIPANTS： A total of 97 neonates with severe asphyxia including 57 boys and 40 girls were selected from Neonatal Intensive Care Unit, Department of Pediatrics, Shenzhen Shajing People＇s Hospital from January 2004 to November 2005. Their gestational age was （38±3） weeks, body mass was （3.2±1.7） kg, and hospitalization duration was （2.8±2.3） hours. All neonates met the diagnostic criteria of with severe asphyxia and all their parents provided the confirmed consent. METHODS： All neonates were treated with inspired oxygen, sedation, stopping terror, decreasing cranial pressure, maintaining a well blood perfusion and normal level of blood glucose （about 5.0 retool/L）. After hospitalization, 0.1 mg/（kg·d） naloxone hydrochloride （Beijing Sihuan Pharmaceutical Technology Co., Ltd.; certification： HI0900021; bullet preparation; 0.4 mg/ampoule） was intravenously dribbled into neonates for 4 - 6 hours, 14 days in total. 2 mL blood was collected from radial artery in neonates at the beginning of hospitalization and at 3 days after naloxone treatment, put in aprotinin-pre-cool tube, mixed evenly, and centrifuged at hypothermia. Plasma was maintained in refrigerator at - 70 ℃. The kit was provided by Neurobiology Department of Shanghai Second Military Medical University of Chinese PLA. Concentration of plasma β-endorphin was measured by using radio-immunity assay.All data were expressed as Mean ± SD and results were compared with paired t test. MAIN OUTCOME MEASURE： Concentration of plasma β-endorphin. RESULTS： All 97 neonates were involved in the final analysis. Concentration of plasma β-endorphin in neonates with severe asphyxia was lower after treatment as compared with that before treatment, and there was significant difference （t = 10.31, P 〈 0.01 ）. CONCLUSION： Naloxone can decrease level of plasma β-endorphin in neonates with severe asphyxia.

VENTRICAL MICROINJECTING ATROPINE OR NALOXONE REDUCES ANALGESIC EFFECTS PRODUCED BY BRAIN STIMULATION IN THE RAT

Stimulating SmI cortex like needling points produced analgesic effect in rats.Under the background of ventrical microinjecting atropine（10μg/2μl）or naloxone（20μg/20μl）tailflick latency（TEL）remained unchanged after stimulating SmI.Comparing atropine group or naloxone group with normal saline group it was shown that there were a statistical difference in TFL between the two groups respectively.Thus,both ACh and endogenous morphine-like factors may participate in analgesic effect as a neurotransmitter of the corticofugal modulation of pain.

POTENT HYPOTENSIVE EFFECTS OF ORPHANIN FQ IN CONSCIOUS STROKE-PRONE SPONTANEOUSLY HYPERTENSIVE RATS

Orphanin FQ（OFQ） or nociceptin is a novel neuropeptide consisting of 17 amino acids. This peptide has a primary structure reminiscent of that of opioid peptide but exhibits an opposite effect to make animals hyperreactive. The effect of this new peptide on cardiovascular function are not completely known. The present study was conducted to investigate the effect of intravenous bolus injection of orphanin FQ on mean arterial blood presure （MABP） in conscious stroke-prone spontaneously hypertensive rats (SHRsp). Adult male SHRsp and Wistar normotensive rats （250～300 g body weight, 2. 5～3 months old） were used in this study. The MABP was measured in the conscious state by a tail-cuff method. In SHRsp model, intravenous bolus injection of orphanin FQ or Tyr1-orphanin FQ （0. 5 mg/kg） induced a prolonged and marked reduc- tion in MABP. The maximum changes in MABP were -30. 2±4. 2 mmHg by orphanin FQ and -28. 2± 4. 7 mmHg by Tyr1-orphanin FQ at 10 min after administration,and this effect lasted over 30 min. The Phe1→Tyr substitution in orphanin FQ was found to retain almost fully hypotensive activity. Pretreatment of SHRsp with naloxone-HCI（60 μg/kg）, 5 min before the injection of orphanin FQ, did not block the hy- potensive effect of orphanin FQ. Therefore, opioid receptors could not account for the hypotensive effect of orphanin FQ in SHRsp. In Wistar rats, intravenous bolus injection of the same dose of orphanin FQ did not cause a change in MABP. These observations suggest that orphanin FQ is a novel hypotensive peptide and may have some role in the regulation of blood pressure in SHRsp, rather than in normotensive rats. The ex-act underlying mechanisms are waiting to be clarified.

Effect of Shenqi Fuzheng Injection and naloxone and BiPAP ventilator on serum inflammatory factors, immune function and blood gas analysis indexes in patients with AECOPD with type Ⅱ respiratory failure

Objective: To investigate the effect of Shenqi Fuzheng Injection combined with naloxone and BiPAP ventilator on serum inflammatory factors, immune function and blood gas analysis indexes in treatment of AECOPD with type Ⅱ respiratory failure. Methods: A total of 82 patients with AECOPD and type Ⅱ respiratory failure were divided into control group (n=40) and observation group (n=42) according to random data table, patients in the control group received naloxone and BiPAP ventilator therapy, and observation group patients were treated with Shenqi Fuzheng Injection on the basis of control group. The levels of serum inflammatory factors, immune function and blood gas analysis indexes were compared between the two groups before and after treatment. Results: There were no significant difference in levels of CRP, TNF-α, IL-6, CD3+, CD4+, CD8+, CD4+/CD8+, PaO2, PaCO2, SaO2 and pH before and after treatment in the two groups. After treatment, the levels of CRP, TNF-α, IL-6, CD8+and PaCO2 in two groups were significantly lower than those in same group before treatment, moreover observation group was significantly lower than control group;and levels of CRP, TNF-α, IL-6, CD8+ and PaCO2 in the observation group was significantly lower than those of the control group, the difference was statistically significant;When compared with the group before treatment, CD3+, CD4+, CD4+/CD8+, PaO2, SaO2 and pH levels of both groups after treatment were significantly increased, and the level of each index of observation group after treatment were significantly higher than the control group, the difference was statistically significant. Conclusion: The clinical effect of Shenqi Fuzheng Injection Combined with naloxone and BiPAP ventilator in treatment of AECOPD with type II respiratory failure is significant, can effectively reduce the body's inflammatory reaction, improve immune function, regulate blood gas analysis index, with a certain clinical value.

Effects of naloxone hydrochloride on pulmonary function, blood gas changes and inflammatory factors in patients with COPD combined with respiratory failure

Objective: To investigate the effects of naloxone hydrochloride on pulmonary function, blood gas changes and inflammatory factors in patients with COPD combined with respiratory failure. Methods: According to random data table method, 80 cases of COPD combined with respiratory failure were randomly divided into the control group (n=40) and observation group (n=40), patients in the control group were treated with noninvasive positive pressure ventilation on the basis of routine symptomatic treatment, on the basis of the treatment of the control group, the observation group received naloxone hydrochloride therapy. The levels of pulmonary function, blood gas changes and inflammatory factors were compared in two groups before and after treatment. Results: The levels of serum FEV1, FVC, PEF, PaCO2, PaO2, PaO2/FiO2, TNF-α and PCT in the two groups before treatment were not statistically significant. After treatment, the levels of FEV1, FVC, PEF in the control group and observation group were (70.01±0.36)%, (2.16±0.41) L, (2.98±0.45) L/s and (81.71±0.53)%, (3.65±0.55) L, (4.36±0.43) L/s, which were significantly higher than those in the same group before treatment, and the levels in observation group were significantly higher than those in the control group;the levels of PaCO2, PaO2 and PaO22/FiO2 in the two groups were (59.62±6.47) mmHg, (65.53±7.36) mmHg, (323.89±10.47) and (46.59±6.64) mmHg, (73.65±8.26) mmHg, (398.64±14.06), compared with the same group before treatment, PaCO2 levels were significantly lower in both groups, and the observation group was significantly lower than the control group, PaO2,PaO2/FiO2 levels were significantly increased in both groups, and the observation group was significantly higher than the control group;the levels of TNF-α, PCT in the two groups were (23.28±4.53) pg/mL, (5.22±2.13) ng/mL and (16.61±4.12) pg/mL, (2.07±1.21) ng/mL, which were significantly lower than those in the same group before treatment, moreover, the observation group levels were significantly lower than those in the control group. Conclusion:Treatment of COPD with respiratory failure by naloxone hydrochloride can effectively reduce the level of inflammatory factors, and improved lung function and blood gas levels, which has important clinical value.

Relationship Between Effect of Electro-Acupuncture on Prolactin Secretion and Several Central Neurotransmitters

We have reported that the central mechanism of acupuncture-induced PRL secretion in non-lactating rats are related to antagonizing hypothalamic dopamine activity; noradrenaline system played little significant role in the acupuncture effect; Υ-aminobutyric-acid system perhaps participated in this effect.This paper further provided evidence that central serotonin and EOP play a stimulatory role in the acupuncture induced secretion of prolactin; acupuncture may antagonize inhibitory effect of H2 histamine receptor activation on prolactin secretion; the possible role of H1-receptor needs further investigation.

Morphine attenuates frustration-like behavior induced by sucrose reward deprivation in rats

In this study, a T-maze-based frustration model in rats was established using sucrose-reward deprivation, The results revealed that rats maintained a 75% preference for the sucrose-reward arm in the reward phase. During the sucrose-deprivation frustration phase, both the preference for the sucrose-deprivation arm （62.5%） and time spent waiting in the sucrose-deprivation arm decreased. Acute injection of morphine increased the preference in a dose-dependent fashion, and prolonged the waiting duration in the sucrose-deprivation arm. These findings indicate that morphine specifically inhibited the frustration response induced by sucrose reward deprivation. To further elucidate the pharmacological mechanisms involved, the opioid receptor antagonist naloxone was given to model rats prior to the injection of morphine. The results revealed that naloxone administration markedly attenuated the anti-frustration-like effects of 3 mg/kg morphine treatment. These findings suggest that morphine attenuates the frustration-like response to reward deprivation in rats through the opioid receptor.