Changes of mu and kappa opioid receptors in cathartic colon of rat

Objective: To observe the changes of mu and kappa opioid receptors in the cathartic colon of rat, and to clarify that whether opioid receptors accounts for the occurrence of slow transit constipation (STC). Methods: The cathartic colon model of rat was made by feeding with laxatives. The activity of mu and kappa opioid receptors in the cathartic colon of rat was measured by radio-ligand binding assay. Results: Compared with the control group, the maximal binding capacity (Bmax) and affinity(Kd) of mu opioid receptor in cathartic colon group were significantly increased (207.00±22.90 fmol/mg·p vs 82.00±14.23 fmol/mg·p, P < 0.01;3.30±0.45 mmol/L vs 2.40±0.57 mmol/L,P < 0.05). The maximal binding capacity of kappa opioid receptor also showed a great increase (957.00±102.41 fmol/mg·p vs 459.00±52.41 fmol/mg·p, P<0.01), but no significant difference of affinity was found between the two groups. Conclusion: The mu and kappa opioid receptors may be involved in the functional disorders of cathartic colon.

Effects of Peripherally Acting Opioid Ligands on Central Opioid Receptors and <i>β</i>-Endorphin Release in Stressed Rats

Using the radioreceptor binding assay, μ-opioid receptor (MOR) affinity in the midbrain of stressed rats was higher than in naive controls. MOR density in the rat frontal cortex was reduced after stress. Intragastric administration of the MOR antagonist naloxone methiodide was followed by an increase in the number of MORs in the frontal cortex. However, the MOR agonist loperamide significantly decreased the density of MORs in the frontal cortex and midbrain of naive animals. Loperamide and naloxone methiodide were shown to prevent an increase in MOR affinity and a decrease in MOR density in the midbrain of rats after restraint stress. The restraint stress was accompanied by an increase in the release of β-endorphin (BE) in the ventral tegmental area (VTA) of control rats. After administration, loperamide slightly decreased the release of BE, naloxone methiodide significantly increased the release of BE in the cingulate cortex (CC) of untreated animals, while drugs had no effect on the release of BE in the VTA. The drugs significantly increased the extracellular level of BE in the CC of stressed animals. Loperamide abolished the increase in the stress-induced release of BE in the VTA. By contrast, naloxone methiodide significantly increased the release of BE in the VTA of stressed rats. Our data indicated that activation of peripheral MORs induces depression of the central part of the μ-opioid system, but suppression of peripheral MOR activity induces activation of the central μ-opioid system, the interaction of which can be modulated by stress.

MODULATION OF A δ-AND C-FIBER EVOKED RESPONSES OF NOCICEPTIVE NEURONS IN THE SUPERFICIAL AND THE DEEPER DORSAL HORN OF THE MEDULLA:ROLE OF OPIOID RECEPTORS(μ, δ_1, δ_2)

The present study was designed to investigate the effects of intravenously administered agonists and antagonists at μ(DAMGO, naloxone,)δ1 (DPDPE,BNTX)andδ2(DELT, NTB)opioid receptors on the Aδ-and C-fiber evoked responses of nociceptive neurons in the superficial and the deeper dorsal horn of the rat medulla.Extracellular single unit recording were made from 70 nociceptive neurons(28 NS,42 WDR) in the superficial dorsal horn and 37 nociceptive neurons(4 NS,33 WDR)in the deeper dorsal horn.All these neurons had an ipsilateral orofacial mechanoreceptive field and majority of these neurons had no spontaneous activity. The latencies for the C fiber evoked responses ranged from 34～105 msec whereas for Aδfiber-evoked responses it ranged from 3～22msec. A clear separation was observed between early and late responses of evoked by Cand Aδ-fiber.Application of DPDPE,DELT and DAMGO produced inhibitory effects on the Aδ-and C-fiber evoked responses of nociceptive neurons in the superficial and thedeeper dorsal horn.By comparison,the inhibition was more pronounced on the C-fiber evoked response than on the Aδ-fiber evoked response,and DAMGO produced a stronger inhibitory action than both DELT and DPDPE. Additionally,DPDPE produced facilitation, or inhibition followed by facilitation on the Aδ-and C-response and the effect had longer latency and longer time course.DPDPE also induced completely oppsite effects on the Aδ-and C-fiber evoked responses.Although the facilitation was observed,the effect was not dose-dependent. Application of BNTX (0.4～1mg/kg),a δ1 receptor antagonist,produced antagonism of DPDPE in 88%(7/8) neurons. Application of the doses (0.7～1mg/kg) of BTB,δ2-receptor antagonist,resulted in antagonism of both DELT and DPDPE. The inhibition of DELT on Aδ-response was antagonized by doses (0.3～1mg/kg)of NTB in 100% (14/14)neurons while the antagonism on C-response was in 79%(11/14) neurons.The effect produced by DPDPE was antagonized by the doses (0.7～1mg/kg) of NTB in 100%(4/4) neurons. However,a smaller dose of NTB(0.3mg/kg)which and antagonize the effect of DELT,did not antagonize the effect of DPEPE in 100%(4/4) neurons. The inhibitory action of DAMGO on Aδ-and C-fiber evoked responses was completely antagonized by naloxone(0. 2mg/kg) in 100% (6/6) neurons. These results suggest that:①μ-and δ-opioid receptors play an important role in modulating Aδ-and Cfiber evoked responses of nociceptive neurons in the superficial and the deeper dorsal horn of the rat medulla; ② The inhibitory action produced by DPDPE, DELT and DAMGO was more pronounced on the C-fiber evoked excitation and indicates that the agonists produce more predominant inhibition on the responses of dorsal horn neurons to noxious stimuli; ③ activation of either δ1-orδ2-opioid receptors produces inhibitory actions on Aδ- and C-response of nociceptive neurons in the superficial and the deeper dorsal horn of the medullal;DPDPE and DELT act at different δ-opioid receptor subtypes in the rat rnedulla; ⑤i.v.-administered NTB can distinguish δ-opioid receptor subtypes in a limited dose range.When administered i. v., 0. 3mg/kg of NTB is selective for δ2-opioid receptor.

YFa and analogs:Investigation of opioid receptors in smooth muscle contraction

AIM:To study the pharmacological profile and inhibition of smooth muscle contraction by YFa and its analogs in conjunction with their receptor selectivity. METHODS:The effects of YFa and its analogs (D-Ala2) YFa, Y (D-Ala2) GFMKKKFMRF amide and Des-Phe-YGGFMKKKFMR amide in guinea pig ileum (GPI) and mouse vas deferens (MVD) motility were studied using an isolated tissue organ bath system, and morphine and DynA (1-13) served as controls. Acetylcholine was used for muscle stimulation. The observations were validated by specific antagonist pretreatment experiments using naloxonazine, naltrindole and norbinaltor-phimine norBNI. RESULTS:YFa did not demonstrate significant inhibition of GPI muscle contraction as compared with mor-phine (15% vs 62%, P = 0.0002), but moderate inhibition of MVD muscle contraction, indicating the role of κ opioid receptors in the contraction. A moderate inhibition of GPI muscles by (Des-Phe) YFa revealed the role of anti-opiate receptors in the smooth muscle contraction. (D-Ala-2) YFa showed significant inhibition of smooth muscle contraction, indicating the involvement of mainly δ receptors in MVD contraction. These results were supported by specific antagonist pretreatment assays. CONCLUSION:YFa revealed its side-effect-free analgesic properties with regard to arrest of gastroin-testinal transit. The study provides evidences for the involvement of κ and anti-opioid receptors in smooth muscle contraction.

Binding properties of C-truncated delta opioid receptors

目的：研究δ阿片受体Ｃ末端在受体结合配体的亲和力及选择性中的作用．方法：在中国苍鼠卵巢细胞（ＣＨＯ细胞）中分别稳定表达Ｃ末端截短３１个氨基酸残基及野生型δ阿片受体，用受体结合分析法研究表达产物与配体的结合特征．结果：表达得到典型突变受体克隆ＣＨＯＴ及野生型受体克隆ＣＨＯＷ．ＣＨＯＴ结合［３Ｈ］ｄｉｐｒｅｎｏｒｐｈｉｎｅ（Ｄｉｐ）及［３Ｈ］［ＤＡｌａ２，ＤＬｅｕ５］ｅｎｋｅｐｈａｌｉｎ（ＤＡＤＬＥ）的Ｋｄ值与ＣＨＯＷ一致，δ选择性激动剂对二者与［３Ｈ］Ｄｉｐ的结合均有很强的抑制作用，且Ｋｉ相似；而μ及κ选择性激动剂则对二者均无抑制作用．结论：δ阿片受体的Ｃ末端与受体结合配体的亲和力及选择性无关．

Expression of mu-opioid receptors in human chronic inflamed knee joint synovium tissue

Objective: To examine the changes of mu-opioid receptors (MORs) expression in human chronic inflamed knee joint synovium tissue. Methods:Knee joint synovium tissues were taken from 21 patients with chronic arthritis (inflamed group) and 6 fresh bodies with normal knee joints (control group). And the expression of MORs was detected by using immunohistochemistry. flow cytometry(FCM) and reverse-transcription polymerase chain reaction (RT-PCR). Results: The expression of MORs in the inflamed group was significantly higher than that in the normal group by using the 3 techniques(P<0. 05). Conclusion: Chronic inflammation enhances the up-regulation of MORs in human knee joint synovium tissue.

Low-dose morphine elicits ventilatory excitant and depressant responses in conscious rats: Role of peripheral <i>µ</i>-opioid receptors

The systemic administration of morphine affects ventilation via a mixture of central and peripheral actions. The aims of this study were to characterize the ventilatory responses elicited by a low dose of morphine in conscious rats;to determine whether tolerance develops to these responses;and to determine the potential roles of peripheral μ-opioid receptors (μ-ORs) in these responses. Ventilatory parameters were monitored via unrestrained whole-body plethysmography. Conscious male Sprague-Dawley rats received an intravenous injection of vehicle or the peripherally-restricted μ-OR antagonist, naloxone methiodide (NLXmi), and then three successive injections of morphine (1 mg/kg) given 30 min apart. The first injection of morphine in vehicle-treated rats elicited an array of ventilatory excitant (i.e., increases in frequency of breathing, minute volume, respiratory drive, peak inspiratory and expiratory flows, accompanied by decreases in inspiratory time and end inspiratory pause) and inhibitory (i.e., a decrease in tidal volume and an increase in expiratory time) responses. Subsequent injections of morphine elicited progressively and substantially smaller responses. The pattern of ventilatory responses elicited by the first injection of morphine was substantially affected by pretreatment with NLXmi whereas NLXmi minimally affected the development of tolerance to these responses. Low-dose morphine elicits an array of ventilatory excitant and depressant effects in conscious rats that are subject to the development of tolerance. Many of these initial actions of morphine appear to involve activation of peripheral μ-ORs whereas the development of tolerance to these responses does not.

Dopamine D₁- and D₂-Receptors in Immunostimulation under Activation of Mu-Opioid Receptors in Mice with Different Psychoemotional States

The purpose of the present study was to analyze the effect of activation of mu-opioid receptors (mu-OR) on the immune response under blockade of postsynaptic D1-and D2-receptors in mice of the C57BL/6J strain displaying either aggressive or depressive-like behaviors in the social conflict model. It is shown that activation of activation of mu-OR with a highly selective agonist DAGO (100 μg/kg) increased significantly IgM-immune response not only in C57BL/6J mice with an unchanged psychoemotional state but also in mice displaying aggressive or depressive-like behaviors in the social stress model (10 days of agonistic confrontations). Selective blockade of DA receptors of the D1-type with SCH-23390 (1.0 mg/kg with DAGO administration) caused a more pronounced elevation of IgM-immune response than DAGO alone while DAGO effect was completely blocked by prior administration of D2-receptor antagonist haloperidol (1.0 mg/kg). At the same time, both SCH-23390 and haloperidol prevented the immune response increase induced by DAGO injection in mice engaged in aggressive or depressive-like behaviors. Thus, in animals not subjected to social stress DAGO-induced immunostimulation is provided only by D2-receptors, whereas in animals with altered psychoemotional state mu-opioid immunostimulation is mediated by both types of DA receptors—D1 and D2. These data provide evidence for different impacts of the main subtypes of DA receptors in the mediation of immunomodulating effects of mu-opioid system under normal and stressful conditions.

Role of opioid receptor heterodimerization in pain modulation and tolerance development

Protein to protein interactions leading to homo/heteromerization of receptor is well documented in literature. These interactions leading to dimeric/oligomers formation of receptors are known to modulate their function, particularly in case of G-protein coupled receptors. The opioid receptor heteromers having changed pharmacological properties than the constituent protomers provides preferences for novel drug targets that could lead to potential analgesicactivity devoid of tolerance and physical dependence. Heterodimerization of opioid receptors appears to generate novel binding properties with improved specificity and lack of side effects. Further the molecules which can interact simultaneously to both the protomers of the heteromer, or to both the binding sites(orthosteric and allosteric) of a receptor protein could be potential therapeutic molecules. This review highlights the recent advancements in exploring the plausible role of heteromerization of opioid receptors in induction of tolerance free antinociception.

Determination of structure-activity relationships between fentanyl analogs and human μ-opioid receptors based on active binding site models

Fentanyl is a potent and widely used clinical narcotic analgesic, as well as a highly selective IJ-opioid agonist. The present study established a homologous model of the human μ-opioid receptor; an intercomparison of three types of μ-opioid receptor protein sequence homologous rates was made. The secondary receptor structure was predicted, the model reliability was assessed and verified using the Ramachandran plot and ProTab analysis. The predictive ability of the CoMFA model was further validated using an external test set. Using the Surflex-Dock program, a series of fentanyl analog molecules were docked to the receptor, the calculation results from Biopolymer/SitelD showed that the receptor had a deep binding area situated in the extracellular side of the transmembrane domains （TM） among TM3, TM5, TM6, and TMT. Results suggested that there might be 5 active areas in the receptor. The important residues were Asp147, Tyr148, and Tyr149 in TM3, Trp293, and His297 in TM6, and Trp318, His319, Ile322, and Tyr326 in TM7, which were located at the 5 active areas. The best fentanyl docking orientation position was the piperidine ring, which was nearly perpendicular to the membrane surface in the 7 TM domains. Molecular dynamic simulations were applied to evaluate potential relationships between ligand conformation and fentanyl substitution.

Impact of Oil and Gas Activities on Acidity of Rain and Surface Water of Niger Delta, Nigeria: An Environmental and Public Health Review

Acidic aerosols resulting from gas flaring and refinery operations in the Niger Delta are a serious environmental and public health concern. Several thousand tons of flue gas components (dust particles, SOx, CO and NOx) are released into the atmosphere by flaring billions of cubic meters of natural gas, refining and volatilizing the spilt oil. Heat wave is generated by flaring travels several meters away from flare points, destroying crops, farm lands, exotic species that are hunters delight while causing extinction of fragile soil flora and fuana. The occurrence of acid rain in the region implies that the natural receptors of the area are the final recipient of land and atmospheric pollutants. In effect, the water needs and public health of the populace are greatly impeded. Nitric and sulphuric acids are regarded as the sole contributors of nitrate and sulphate in precipitation influenced by combusted hydrocarbons: fine nitrate aerosols that dissolve in rain water are conversion products of NO2 that arise from flaring, power plants and motor vehicles. Scientific evidence has shown that rain water and surface water quality in the Niger Delta can accentuate the poor health burden, and may be perpetuated through generations unborn. Diagnostic health risk assessment has revealed that drinking nitrate contaminated water may be associated with spontaneous miscarriage, ectopic pregnancy, adult malignant lymphomas, soft tissues sarcomas, cancers and lesions with added health burden associated with heavy metals and other ions. All these pose public health emergency and may significantly entrench health risk for generations to come. Therefore, this manuscript is intended to close certain gaps that were not covered by toxicological information and available data on environmental and food contamination and human internal exposure: it will serve as a continuous reminder and a useful guide to public health policy makers, workers and community based physicians.

Immunohistochemical identification of dynorphin A and Kappa opioid receptor-1 in the digestive system of scallop Chlamys farreri

Little is known about the roles of dynorphin and Kappa opioid receptor(KOR) in mollusks. In this study, we aim to determine the distribution of dynorphin A and KOR-1 in the digestive system of the scallop Chlamys farreri. Using immunohistochemical staining, we confirmed the expression of dynorphin A and KOR-1 in the digestive system of C. farreri. Dynorphin A immunopositive cells were identified in intestine and hepatopancreas. In intestine, small and spherical dynorphin A immunopositive cells(4–9 μm in diameter) were scattered among the long columnar epithelial cells(ECs). In hepatopancreas, cells containing masses(5–14 μm in diameter) of dynorphin A immunopositive products were observed in epithelium of acinis. These immunopositive cells may be synthetic and/or secretory cells of dynorphin A. Dynorphin A immunoreactive products were commonly observed in epithelium and connective tissue(CT) of labial palps, mouth labia and stomach, which presented in forms of grains, fibers or flakes. KOR-1 immunoreactive material was observed in ECs and CTs of labial palps, mouth labia and stomach, intestine and hepatopancreas. The distribution of both dynorphin A and KOR-1 in the digestive organs suggests an involvement of dynorphin via KOR-1 in the functional regulation of the digestive system of C. farreri.

Analgesic and anti-inflammatory potential of aerial parts of the Daphne mucronata Royle extract in mice: Opioid-independent action

Objective: To investigate the analgesic and anti-inflammatory property and possible involvement of opioid receptors of ethyl acetate extract from aerial parts of Daphne mucronata(D. mucronata) in mice by formalin test.Methods: Single doses of 2.5, 5.0 and 10.0 mg/kg of body weight of ethyl acetate extract of D. mucronata were intraperitoneally administered to the mice 30 min before analgesic test. The anti-nociceptive effect of preparations was evaluated based on the formalin in mice.Results: The results indicated that the extract(2.5, 5.0 and 10.0 mg/kg) increased the pain threshold of mice and induced analgesia in both phases of formalin test. Like morphine sulfate(5.0 mg/kg, i.p.), the extract also showed more effective analgesic effect on the late phase of formalin test. Pre-treatment of animals with naloxone(5.0 mg/kg i.p.)did not inhibit the effects of the extract.Conclusions: Our findings suggest that D. mucronata contains potential analgesic and anti-inflammatory compounds which support its traditional use. Moreover, it seems that the analgesic and anti-inflammatory effects of the extract is mediated by non-opioid mechanisms. Further pharmacological studies are required to determine whether the analgesic mechanisms are actually responsible for such properties.

Endorphinergic Attenuation of Distress by Concomitantly Enhancing Endogenous Opioid Release and Switching Opioid Receptor Signaling from an Excessively Excitatory to a Normal Inhibitory Mode

The endogenous opioid system plays a significant role in the modulation of distress in many psychiatric, neurologic, and neurodevelopmental disorders. Many clinical distress symptoms show similarities to the excitatory autonomic withdrawal effects in chronic opioid-dependent animals and humans, as well as to the “quasi-morphine withdrawal syndrome” evoked in naive rodents shortly after acute systemic injection of cyclic AMP-phosphodiesterase (cAMP-PDE) inhibitors. These symptoms result from excessive excitatory opioid receptor signaling and increased endorphin release. Pharmacologic analyses of the remarkably plastic bimodal (excitatory/inhibitory) signaling functions of opioid receptors have utilized microelectrode recordings from opioid-sensitive neurons in tissue cultures of mouse sensory ganglia and hot-water tail-flick assays in mice. These studies led to development of specific chemical formulations that switch opioid receptor signaling from an excessively excitatory to a normal inhibitory mode. Critical combinations of cAMP-PDE inhibitors that release endorphins plus specific agents that switch opioid receptors from excitatory Gs-coupled to inhibitory Gi/Go-coupled signaling were shown to attenuate hyperalgesia and distress evoked by diverse chemical stressors in mouse tail-flick assays. Both the “quasi-morphine withdrawal syndrome” in naive rodents as well as the excitatory withdrawal effects in chronic, opioid-dependent animals and humans may be manifestations of a common Endorphinergic Distress Syndrome (EDS). We suggest that many distress symptoms are caused by EDS, a dysfunctional imbalance in the endogenous opioid system, consisting of abnormal endorphin levels, together with opioid receptors predominately in their excitatory mode. Therefore, concomitantly enhancing endogenous opioid release and switching excessive excitatory opioid receptor signaling to inhibitory signaling can attenuate these distress symptoms. Trials of a critically formulated oral preparation, containing both endorphin enhancers and opioid receptor switchers, have resulted in long-term anxiolytic efficacy and enhanced calm and mental clarity in large numbers of individuals with distress symptoms. These endorphinergic formulations may provide treatment for the emotional and physical distress associated with many psychiatric, neurologic, and neurodevelopmental disorders.

Corelation Between Single Nucleotide Polymorphisms in Mu Opioid Receptor Exon 2 and Stereotypic Behaviour in Sows

Three breeds of sows were observed to investigate the relationship between Single Nucleotide Polymorphisms（SNPs） in Mu Opioid Receptor（MOR）and stereotypic behaviour,such as,sham-chewing,bar biting and standing still in order to better understand the mechanism of stereotypic development of the animals in restrained conditions.MOR exon 2 partial sequences were amplified to analyze single nucleotide polymorphisms by PCR-SSCP.One SNP,a silence mutant was found.A significant difference （P〈0.01）was found in the frequency of genotypes in these 3 breeds where only the BB genotype,which was identical to that published in GenBank,was found in the Duroc breed,while no AA genotype was found in Landrace,3 genotypes AA,BB and AB were found in Yorkshire.The result also indicated that the individuals with AA and AB genotypes tended to be more active in sham-chewing than those with the BB genotype（P〈0.05）.The overall results of this study suggested that sham-chewing of sows may be subjected to both genetic control and environmental conditions,but activity level was more likely to be affected by their environment.We can putatively draw the conclusion that MOR gene has effect on the sham-chewing behavioral traits of sow.

“New-Look” Opioids: Biased Ligands

Between the illicit use of opioids and attendant overdoses, and accidental overdoses with prescribed drugs, overuse of opioids has become a serious problem. At the same time, finding that fine balance between minimizing the risk of opioid misuse and abuse while at the same time providing access to treatment for patients who need pain control presents an ongoing challenge. Efforts to discover and develop better agents have led to what we term “new-look” opioids. We summarize here one such approach—known as biased ligands. By targeting a subset of GPCR signal transduction, this approach attempts to increase the separation between therapeutic and adverse effects.

Effect of Synthetic Leucopyrokinin Analog [D-AlaS]-[2-8]-Leucopyrokinin （[D-AlaS]-[2-8]-LPK） on Opioid-lnduced Analgesia in Rats

The study was undertaken in order to evaluate effect of synthetic insect neuropeptide leucopyrokinin analog, [D-Ala5]-[2-8]-LPK, on analgesia induced by selective agonists of/a-, 6- and l〈-opioid receptors. The study was performed on male Wistar rats, which a week before the experiments were implanted with polyethylene cannulas into the lateral brain ventricle （icv）. Effect of prior administration of [D-Ala5]-[2-8]-LPK on analgesia induced in rats by next icv administration of equimolar dose of μ-, δ- and -opioid agonists： DAMGO, DPDPE and GR fumarate respectively, was evaluated. Antinociceptive effect was determined in rats by the test of the tail immersion. It was found that two doses of 5 and 10 nmols icv of [D-AlaS]-[2-8]-LPK inhibited analgesia in rats by equimolar doses of DAMGO. This analog also transiently （only in two time intervals） and in one dose of 10 nmols inhibited analgesia induced in rats by icv administration of equimolar DPDPE dose of 10 nmols icv. Obtained results indicate that [D-AlaS]-[2-8]-LPK inhibits antinociceptive effect of DAMGO and in part of DPDPE, i.e. mainly antagonized ~t-opioid receptors. These results correspond with results of our previous study that selective antagonists of μ- and δ-opioid receptors blocked antinociceptive effect of synthetic insect neuropeptide leucopyrokinin and of it active analog [2-8]-leucopyrokinin. We regard that [D-AIaS]-[2-8]-LPK, the first discovered antagonist of leucopyrokinin may be a useful as a probable tool substance in the study of biological effects of insect-derived peptides either in invertebrates or in mammals.

Peroxisome proliferator-activated receptor delta+294T>C polymorphism and serum lipid levels in the Guangxi Bai Ku Yao and Han populations

Objectives The association of peroxisome prolif-erator -activated receptor delta(PPARD) +294T】C polymorphism and serum lipid levels is inconsistent in several previous studies.Bai Ku Yao is an isolated association of PPARD +294T】C(rs2016520) polymorphism and several environmental factors with serum lipid levels in the Guangxi Bai Ku Yao and Han populations.Methods A total of 609 subjects of Bai Ku Yao and 573 participants of Han Chinese were randomly selected from our previous stratified randomized cluster samples.Genotyping of the PPARD +294T】C polymorphism was performed by polymerase chain reaction and restriction fragment length polymorphism combined with gel electrophoresis, and then confirmed by direct sequencing.Results The levels of serum total cholesterol(TC),high-density lipoprotein cholesterol(HDL-C),apolipoprotein(Apo) AI and ApoB were lower in Bai Ku Yao than in Han(P【0.001 for all).The frequency of T and C alleles was 77.50%and 22.50%in Bai Ku Yao,and 72.43%and 27.57%in Han (P【0.01);respectively.The frequency of TT,TC and CC genotypes was 60.59%,33.83%and 5.53%in Bai Ku Yao, and 52.18%,40.50%and 7.32%in Han(P【0.05);respectively. The levels of LDL-C,ApoB and the ratio of ApoAI to ApoB in Bai Ku Yao were different among the three genotypes in females but not in males(P【0.05 for all).The subjects with TT and TC genotypes had lower serum LDL-C and ApoB levels and higher the ratio of ApoAI to ApoB than the CC genotype in females.The levels of TC and ApoB in the total Han population were different among the three genotypes (P【0.05 for all).The C allele carriers had higher serum TC and ApoB levels than the C allele noncarriers.When serum lipid levels were analyzed according to sex,the difference in serum TC levels in Han was significant in males(P【0.01) but not in females,whereas the difference in serum ApoB levels was significant in females(P【0.05)but not in males. Serum TC and ApoB levels were correlated with genotypes in Han(P【0.05 for each) but not in Bai Ku Yao.Serum lipid parameters were also correlated with sex,age,body massindex, alcohol consumption,cigarette smoking,and blood pressure in both ethnic groups.Conclusions These results suggest that the association of PPARD +294T】C polymorphism and serum lipid levels is different between the Bai Ku Yao and Han populations.The discrepancy between the two ethnic groups might partly result from different PPARD +294T】C polymorphism or PPARD gene-enviromental interactions,subgroup of the Yao minority in China.

Molecular characterization and functional expression of opioid receptor-libe_1 receptor

The opioid receptor-libel receptor (ORL), an orphan receptor whose human and murine complementary DNAs,has been characterized recently. ORL transcripts are particularly abundant in the central nervous system. We demonstrated that ORL expressed in human neuroblastoma SK-N-SH and SH-SY5Y cell lines by radioligand binding assay, reverse transcription polymerase chain reaction (RT-PCR) and Northern analysis in the present study. Stimulation with ORL1 specific agonist, nociceptin/orphanin Fo, increased [34S]GTPrγS binding to SK-N-SH cell membranes (EC50 = 14 ±0.45 nM), and attenuated forskolin-stimulated accumulation of cellular cAMP (EC50= 0.80 ±0.45 nM, indicative that activation of ORL1 activates G proteins and inhibits adenylyl cyclase. Activation of ORL1 receptor was also accessed using CHO:hORL1 cell line by microphysiometer. Treatment of nociceptin/orphanin FQ increased extracellular acidification rate significantly.