Anesthetic effect of phenobarbital sodium on female BALB/c mice

Objective:Anesthetics are of great importance in avoiding severe pain and suffering in animals and ensuring experimental progress.This study was aimed at elucidating the anesthesia score of phenobarbital sodium as a general anesthetic at different concentrations and doses in BALB/c mice,and finding the suitable anesthesia strategies for experimental surgeries.Methods:Phenobarbital sodium was administrated intraperitoneally at the doses of 75,100,125,150,and 200 mg/kg and randomly in different concentrations(2%,5%,and 10%)to female BALB/c mice.The anesthesia score was evaluated based on the stimulus index including tail-pinch,front and hind limb withdrawal,and eyelid reflexes.The speed and duration of anesthesia in different groups were recorded per the occurrence and duration of the righting reflex.Results:The anesthetic effect of phenobarbital sodium on female BALB/c mice showed an obvious dose-dependency.Respiratory suppression caused by high-dose anesthesia may lead to mouse death.Based on the anesthesia score,when the phenobarbital sodium treatment was greater than or equal to five percent or 200 mg/kg,more than 80%mice meet the anesthesia depth that surgical operation needed.The rates of achieving surgical anesthesia depth(standard-reaching rate)in mice treated with 2%sodium phenobarbital were 0%in the 75 mg/kg group,0%in the 100 mg/kg group,50%in the 125 mg/kg group,66.7%in the 150 mg/kg group,and 100%in the 200 mg/kg group.The standard-reaching rate of mice treated with 5%concentration of phenobarbital sodium were:0%in the 75 mg/kg group,0%in the 100 mg/kg group,83.33%in the 125 mg/kg group,100%in the 150 mg/kg group,and 100%in the 200 mg/kg group.The standard-reaching rate of mice treated with 10%concentration of phenobarbital sodium were:50%in the 75 mg/kg group,66.7%in the 100 mg/kg group,100%in the 125 mg/kg group,100%in the 150mg/kg group,and 100%in the 200 mg/kg group.Sedation and hypnosis were induced in the low-concentration dose group,and anesthesia was induced in the high-concentration dose group.In the 5%and 125 mg/kg phenobarbital sodium groups,the mortality rate of mice was 0,the anesthesia induction time was(35.5±7.92)minutes,and the anesthesia duration was(106±39.59)minutes.In the 5%and 150 mg/kg phenobarbital sodium groups,the mortality rate of mice was 0,the anesthesia induction time was(34.83±5.27)minutes,and the anesthesia duration was(131.7±36.75)minutes.Conclusion:Phenobarbital sodium alone can provide appropriate general anesthesia in female BALB/c mice.Both the concentration and dose of phenobarbital sodium can affect the anesthetic effect.On the basis of our findings,we recommend the 5%and 125 mg/kg and 5%and 150 mg/kg concentration–dose combinations of phenobarbital sodium for anesthetizing mice according to the surgical requirement.

Computer Simulation and Experimental Investigations of Phenobarbital Molecular Imprinting System

The interaction process between the phenobarbital（PHN） and acrylamide（AM） was studied using the M062X/6-31G（d,p） method. The PHN and AM were used as the template and functional monomer,respectively. The molecular electrostatic potential（MEP） was simulated for predicting the reactive sites. The atoms in molecules theory helped to reveal the imprinting mechanism and optimize the molar ratios for PHN and AM. The molecular imprinted polymers（MIPs） containing PHN were synthesized through the precipitation polymerization. The diameter range of the obtained MIPs was from 150 to 390 nm. According to the computational results,MIPs with the molar ratio of PHN and AM equal to 1：6 showed high selective adsorption for PHN. The apparent maximum adsorption quantity（Q_（max）） of MIPs toward PHN was 7.9 mg/g,and the Qmax of nonimprinted polymer microspheres（NIPs） was 3.2 mg/g. Herein,the studies can provide theoretical and experimental references for the controllable fabrication of MIPs.

Theoretical Study on the Structures and Properties of Phenobarbital Imprinted Polymers

Recently, the investigation of novel molecularly imprinted polymers（MIPs） has attracted a lot of interest and becomes a fascinating field. The phenobarbital（PHN） was taken as an imprinted molecule and the 2-vinyl-4,6-diamino-1,3,5-triazine（VDAT） was considered as a functional monomer in this study. The geometry optimization, natural bond orbital（NBO） charge, and molecular electrostatic potential（MEP） of PHN and VDAT were studied at the M062 X level belonging to one of the hybrid density functional theories. Furthermore, we discussed the bonding conditions of PHN molecular imprinted polymers（PHN-MIPs） via the hydrogen bond length and atoms in molecules（AIM） theory. The rebinding property of PHN-MIPs was also researched. The results of MEP and NBO charge analysis were coincident. The stability property was excellent when the ratio of PHN and VDAT was 1：4. Except the classic hydrogen bonds, non-classical hydrogen bonds also existed in the imprinted polymers. By simulating the rebinding energies between the pentobarbital（PNT）, barbital（BAR）, and PHN-MIPs after the elution of PHN, the rebinding property of PHN-MIPs to PHN was excellent when PNT and BAR existed all at once. This research can provide theoretical reference for the synthesis and characterization of novel PHN-MIPs.

PHENOBARBITAL FOR THE PREVENTION OF IVH INCHINESE PREMATURE INFANTS

Objectivs To evaluate the effect of phenobarbital in preventing intraventricular hemorrhage inpremature infants. Methods A randomized controlled trial for the prevention of neonatal intraventricularhemorrhage (IVH) was carried out in 57 Chinese premature infants with gestation of 34 weeks. These prematureinfants were randomly assigned to prevented (23 cases) or control (34 cases) groups. Results No statisticallysignificant differences in general data between the two groups were found. It was noticed that the average Apgarscore in prevented group was lower than that in the control group. The average age at the time of the loading dosesof phenobarbital was 8.9± 8.3 (0.5～25)h (outborn babies usually delay to receive phenobarbital), and the averageduration of the maintenance dose was 5d. The mean value of serum phenobarbital level obtained on day 4 was 20.9±5.2mg/L. The results demonstrated that the incidence of IVH and severe IVH decreased significantly inprevented group (74% vs 97%, P<0.05 and 13% vs 62%, P<0.01 respectively). NO severe IVH and hydrocephaluswere develOPed in the infants with IVH grade Ⅱ in the prevented group. While 7 infants with grade Ⅱ developedgrade Ⅲ during very short period, and 2 infants had to shunt for hydrocephalus in the control group. Infants onphenobarbital had not observed any side - effects. The duration of clinical symptoms was markedly shortened in theprevented group. Conclusion The study supports the use of phenobarbital for the prevention of IVH and severeIVH in Chinese premature infants. It is suggested that phenobarbital prophylaxis should be routinely carried outin all preterm infants with gestational age 34 weeks within 6h alter birth.

Therapeutic effect of phenobarbital combined with mild hypothermia on neonatal asphyxia

Objective: To analyze the efficacy of phenobarbital combined with mild hypothermia in the treatment of neonatal asphyxia. Methods: Subjects selected 50 children with neonatal asphyxia treated in our hospital from February 2016 to August 2017. They were randomly divided into a control group and an observation group with 25 cases in each group. The two groups of children were given routine resuscitation treatment. The control group was given phenobarbital injection on the basis of this. The observation group was given phenobarbital combined with mild hypothermia treatment, the heart rate, respiration, blood pressure changes, liver and kidney function, coagulation function and blood gas analysis after treatment were analyzed and compared between the two groups. At the same time, the outcomes and NBNA scores of the two groups were compared. Results: During the course of treatment, the heart rate of the observation group at the same time period was significantly lower than that of the control group (P<0.05);After treatment, Respiratory, systolic and diastolic blood pressures in two groups of children, serum urea (BUN), serum creatinine (Scr), thromboplastin time (PT), plasma thrombin time (TT), arterial serum pH, blood, There was no significant difference in partial pressure of oxygen (PO2) and remaining alkali (BE) (all P>0.05), the alanine aminotransferase (ALT), aspartate aminotransferase (AST), and NBNA scores in the observation group were significantly higher than those in the control group (all P<0.05), the length of hospitalization and feeding time were significantly lower than those in the control group (all P<0.05). Conclusion: Phenobarbital combined with mild hypothermia for neonatal asphyxia can significantly improve brain damage and liver and kidney function in children, reduce acidosis and respiratory depression, and have no negative effect on heart rate, blood pressure, coagulation function, etc. The efficacy is good and its safety is high.

PHENOBARBITAL FOR THE PREVENTION OF INTRACRANIAL DAMAGE IN CHINESE NEONATES WITH SEVERE ASPHYXIA

Objective TO evaluate the effect of phenobarbital on preventing intracranial damage and seizurein Chinese neonates with severe asphyxia. Methods A control trial was carried out in 60 Chinese neonates withsevere asphyxia. 30 neonates received loading dose of phenobarbital on an average of 5.6h of age. Results Themean value ol phenobarbital serum level obtained at the 4th day after birth was 21.9μg/ml. No significantdifference was observed in the two groups in terms of birth weight, gestational age, Apgar scores, sex, etc. Theimaging diagnosis within 3d of age in all subjects showed normal brain in 14, brain edema in 9 andintraventricular hemorrhage (IVH) in 7 in the treated group with a 53.3% of total complication rate, and normalbrain in 5, brain edema in 15, IVH in 9 and subarachnoid hemorrhage (SAH) in 1 in the untreated group with a83.3% of total complication rate. The incidence of intracranial damage in the untreated group was significantlyhigher than that in the treated group (83.3% vs 53.3%, P<0.05). In the treated group, 4 neonates with seizuresymptom were effectively controlled soon, and none of the other 26 developed seizure. The period of seizure in thetreated group was significantly shorter than that in the untreated group (P<0.05). Other clinical symptoms werealso sooner improved and no side effects were observed among the neonates treated with phenobarbital. Con-clusion The incidence of postasphyxiated intracranial damage was obviously decreased, and seizure could beprophylactically intervened by phenobarbital. It is recommended that early application of preventive phenobarbitalin severely asphyxiated neonates is reasonable in reducing the incidence of intracranial lesions and subsequentselzures.

Phenobarbital in the treatment of alcohol withdrawal syndrome

Alcohol withdrawal syndrome(AWS)is a serious disorder affecting alcohol-dependent patients who abruptly stop or reduce their drinking.Mild or moderate AWS usually appears within 6 to 24 h after the last drink,and symptoms may include increased blood pressure and rapid pulse,tremors,high fever,irritability,anxiety,headache,nausea,and vomiting.These symptoms may progress to a more severe AWS characterized by delirium tremens,seizures,coma,cardiac arrest,and death.This article will analyze the phenobarbital(PB)treatment of AWS and make a brief review'.

EFFECTS OF CONVULSANT PENICILLIN AND ANTICONVULSANT SODIUM PHENOBARBITAL ON ~3H-GABA UPTAKE IN MOUSE BRAIN SLICES

It has long been demonstrated that penicillin causes convulsion and sodium phenobarbital depresses this effect. It has been shown that these drugs alter the physiological activity of the inhibitory neurotransmitter, GABA, in the CNS. However, the mechanism of action is not yet well understood. Our previous

Stereoselective propranolol metabolism in two drug induced rat hepatic microsomes

AIM To study the influence of inducers BNFand PB on the stereoselective metabolism ofpropranolol in rat hepatic microsomes.METHODS Phase Ⅰ metabolism of propranololwas studied by using the microsomes induced byBNF and PB and the non-induced microsome asthe control.The enzymatic kinetic parameters ofpropranolol enantiomers were calculated byregression analysis of Lineweaver-Burk plots.Propranolol concentrations were assayed byHPLC.RESULTS A RP-HPLC method was developed todetermine propranolol concentration in rathepatic microsomes.The linearity equations forR（+）-propranolol and S（-）-propranolol wereA=705.7C+311.2C（R = 0.9987）and A= 697.2C+311.4C（R = 0.9970）respectively.Recoveriesof each enantiomer were 98.9%,99.5%,101.0%at 60 μmol/L,120 μmol/L,240 μmol/Lrespectively.At the concentration level of120 μmol/L,propranolol enantiomers weremetabolized at different rates in differentmicrosomes.The concentration ratio R（+）/S（-）of control and PB induced microsomesincreased with time,whereas that of microsomeinduced by BNF decreased.The assayed enzymeparameters were:1.Km.Control group:R（+）30+8,S（-）18+5;BNFgroup:R（+）34+3,S（-）39±7;PB group:R（+）38±17,S（-）36±10.2.Vmax.Control group:R（+）1.5+0.2,S（-）2.9±0.3;BNF group:R（+）3.8±0.3,S（-）3.3±0.5;PB group:R（+）0.07±0.03,S（-）1.94±0.07.3.Clint.Control group:R（+）60±3,S（-）170±30;BNF group:R（+）111.0±1,S（-）84± 5;PBgroup:R（+）2.0±2,S（-）56.0±1.Theenzyme.parameters compared with unpaired ttests showed that no stereoselectivity wasobserved in enzymatic affinity of threemicrosomes to enantiomers and their catalyticabilities were quite different and hadstereoselectivities.Compared with the control,microsome induced by BNF enhanced enzymeactivity to propranolol R（+）-enantiomer,andmicrosome induced by PB showed less enzymeactivity to propranolol S（-）-enantiomer whichremains the same stereoselectivities as that ofthe control.CONCLUSION Enzyme activity centers of themicrosome were changed in composition andregioselectivity after the induction of BNF andPB,and the stereoselectivities of propranololcytochrome P450 metabolism in rat hepaticmicrosomes were likely due to thestereoselectivities of the catalyzing function inenzyme.CYP1A subfamily induced by BNFexhibited pronounced contribution to propranololmetabolism with stereoselectivity to R（+）-enantiomer.CYP2B subfamily induced by PBexhibited moderate contribution to propranololmetabolism,but still had the stereoselectivity ofS（-）-enantiomer.

苯巴比妥预防早产儿脑室内出血的体会

目的：探讨苯巴比妥预防早产儿脑室内出血的疗效。方法：以2002．6--2004．6月住院74例日龄≤12h的早产儿为研究对象，设预防组，于入院后立即给予苯巴比妥负荷量，24h后给予维持量，疗程5d。将2000．6～2002．6月所入院早产儿68例日龄≤12h早产儿设为对照组未用苯巴比妥，比较两组IVH的发生率及严重IVH的发生率。结果：防治组IVH发生率为24％较对照组47％显著降低P<0．01，严重IVH发生率4％，较对照组16％明显降低(P<0．01)。结论：苯巴比妥能有效预防早产儿脑室内出血，减少严重IVH发生。

左乙拉西坦对苯巴比妥血药浓度的影响

目的:针对1例临床治疗中出现的左乙拉西坦(levetiracetam,LEV)剂量调整显著影响苯巴比妥(phenobarbital,PB)血药浓度的案例,初步探究其两药相互作用的机制。方法:(1)Wistar大鼠随机分为苯巴比妥单用组(60 mg·kg-1)与苯巴比妥+左乙拉西坦合用组(PB60 mg·kg-1+LEV150 mg·kg-1),单次给药后,检测苯巴比妥血药浓度。(2)Wistar大鼠随机分为常规剂量组(PB120 mg·kg-1·d-1+LEV300 mg·kg-1·d-1)与高剂量组(PB120 mg·kg-1·d-1+LEV600 mg·kg-1·d-1),分别给药27 d,于每日首次给药前眼眶采血监测苯巴比妥血药浓度,并于第27天给药后0.5 h,2 h,4 h眼眶采血并处死大鼠,检测苯巴比妥血药浓度和肝脏,肾脏,脑组织药物浓度。结果:(1)单用组(PB)与合用组(PB+LEV)相比较,单次给药后苯巴比妥在大鼠体内各时间点血药浓度无统计学差异(P>0.05)。(2)长期给药期间(共计27 d),高剂量组与常规剂量组相比,苯巴比妥血药浓度未见统计学差异(P>0.05)。(3)第27天给药后高剂量组与常规剂量组相比,苯巴比妥在0.5,2,4 h的血药浓度及脑组织,肝脏,肾脏药物浓度均无统计学差异(P>0.05)。结论:本实验显示常规剂量和高剂量的左乙拉西坦均不会改变大鼠体内苯巴比妥的血药浓度,且高剂量左乙拉西坦并未导致苯巴比妥脑药浓度,肝肾组织药物浓度发生显著性变化。