不同猪种5-羟色胺受体基因的表达及其与肉质的相关性分析

为研究5-羟色胺（5-HT）受体基因在不同猪种的表达及其与肉质的关系,试验选取淳安花猪与杜长大三元猪各12头,同时饲喂,达上市体重时分别屠宰,测定胴体、肉质性状及肌肉、脂肪中的5-HT受体基因表达量。结果表明：淳安花猪、杜长大三元猪的平均屠宰体重分别为88.1、102.4kg;淳安花猪的板油率、背膘厚、肌内脂肪等指标均显著高于杜长大三元猪（P〈0.05）;屠宰率、眼肌面积杜长大三元猪显著高于淳安花猪（P〈0.05）。5-HT2A、5-HT7受体基因在2个猪种脂肪组织中的表达量均显著高于肌肉组织（P〈0.05）,杜长大三元猪的肌肉中5-HT2A、5-HT7表达量显著低于淳安花猪（P〈0.05）,而脂肪中表达量两猪种间差异不显著。5-HT2A、5-HT7受体基因表达量与屠宰肉质指标之间基本呈负相关,尤其是肌肉中的5-HT2A表达量,呈较强负相关（杜长大三元猪）或显著负相关（淳安花猪）。研究初步认为,5-HT受体基因在中外猪种之间存在表达差异,并与屠宰肉质性状具有相关性。     

吡喹酮和硝硫氰醚对日本血吸虫体内5-HT含量的影响

本文研究了吡喹酮和硝硫氰醚与日本血吸虫拟似神经递质 5-羟色胺间的关系。以吡喹酮 ( 5× 1 0 - 7mol/ L和 5× 1 0 - 8mol/ L )、硝硫氰醚 ( 1 0 - 4mol/ L和 1 0 - 5mol/ L )分别培养日本血吸虫成虫 4h和 8h ,反相离子对高效液相法测定其体内 5-HT的含量变化。结果显示 :吡喹酮和硝硫氰醚对日本血吸虫体内 5-HT等含量的影响与对照相比均无显著性差异。表明二者抗虫作用似不通过影响虫体 5-HT的生物合成和降解。     

Endogenous 5-HT outflow from chicken aorta by 5-HT uptake inhibitors and amphetamine derivatives

Chemoreceptor cells aggregating in clusters in the chicken thoracic aortacontain 5-hydroxytryptamine (5-HT) and have voltage-dependent ion channels and nicotinicacetylcholine receptors, which are characteristics typically associated with neurons. Theaim of the present study was to investigate the effects of 5-HT uptake inhibitors,fluvoxamine, fluoxetine and clomipramine (CLM), and amphetamine derivatives,p-chloroamphetamine (PCA) and methamphetamine (MET), on endogenous 5-HToutflow from the isolated chick thoracic aorta in vitro. 5-HT wasmeasured by using a HPLC system with electrochemical detection. The amphetaminederivatives and 5-HT uptake inhibitors caused concentration-dependent increases inendogenous 5-HT outflow. PCA was about ten times more effective in eliciting 5-HT outflowthan MET. The 5-HT uptake inhibitors examined had similar potency for 5-HT outflow. PCAand CLM increased 5-HT outflow in a temperature-dependent manner. The outflow of 5-HTinduced by PCA or 5-HT uptake inhibitors was independent of extracellular Ca²⁺concentration. The 5-HT outflow induced by CLM, but not that by PCA, was dependent on theextracellular NaCl concentration. These results suggest that the 5-HT uptake system of5-HT-containing chemoreceptor cells in the chicken thoracic aorta has characteristicssimilar to those of 5-HT-containing neurons in the mammalian central nervous system(CNS).     

The analgesic effects of intrathecal xylazine and detomidine in sheep and their antagonism with systemic atipamezole

OBJECTIVE: To evaluate the analgesic and adverse side effects of intrathecal (IT) xylazine (XYL) and detomidine (DET) and the subsequent effects of two doses of intravenous (IV) atipamezole (ATI). STUDY DESIGN: Prospective, randomized, cross-over. ANIMALS: Five adult healthy female sheep with mean body mass of 55 +/- 2.3 kg. Material and methods Each sheep underwent four treatments: 1) 50 microg kg(-1) XYL IT and 5 microg kg(-1) ATI IV, 2) 50 microg kg(-1) XYL IT and 2.5 microg kg(-1) ATI IV, 3) 10 microg kg(-1) DET IT and 5 microg kg(-1) ATI IV, 4) 10 microg kg(-1) DET IT and 2.5 microg kg(-1) ATI IV. Pain threshold (TH) was tested by applying pulsed and stepwise incremental direct current to the skin overlying the pastern. The current at the point of foot lift was recorded as the TH. Heart rate (HR), mean arterial pressure, arterial oxygen (PO(2)) and carbon dioxide (PCO(2)) tensions were monitored. Outcomes were derived as differences between baseline assessment and measurements after treatment. Two-way anova was used to analyse drug effects, treatment differences between groups were examined with an F-test or Wilcoxon's rank sum test in case of non-parametric data distribution. p was set at 0.05. RESULTS: Both drugs increased the pain TH, caused small increases in PCO(2), and small decreases in HR, the latter was only significant for XYL recipients. Xylazine produced a significantly higher TH, more rapidly and for longer than DET. Atipamezole only significantly affected PaCO(2) in the XYL group 2. The pain TH was not affected in either group after IV ATI. CONCLUSIONS: At the doses used, IT XYL, and to a lesser extent DET, induced pastern analgesia. Atipamezole 5 microg kg(-1) IV antagonized some side effects without affecting analgesia. CLINICAL RELEVANCE: Intrathecal XYL may be useful as an analgesic in sheep. Its safety is increased because IV ATI antagonizes side effects, but not analgesia.     

莱芜黑山羊松果体内含5—羟色胺细胞及纤维的免疫组化观察

采用免疫组化SABC法,对冬季莱芜黑山羊松果体中含5羟色胺细胞及纤维进行研究。结果显示:①松果体内存在大量5羟色胺阳性的松果体细胞,细胞轮廓较清晰。②松果体的蒂部、被膜及内部含有丰富的5羟色胺纤维,且呈现出不同的形态和免疫反应强度。     

鸡红核和蓝斑核的细胞构筑及其5-HT神经元的分布研究

光镜下观察鸡脑内红核、蓝斑核细胞构筑及其5-羟色胺神经元分布情况,结果表明:红核没有明显的亚核划分,由大、中、小3种细胞构成;鸡脑内有蓝斑核存在,核团呈横向宽、背腹向扁的板状,位于脑桥前部的室底灰质腹外侧区,被盖背外侧核后方,主要由小型细胞构成。用免疫组织化学SP法的研究结果表明红核和蓝斑核内有5-HT阳性神经元分布,这在禽类属首次提出。     

Food intake and rumen motility in dwarf goats. Effects of some serotonin receptor agonists and antagonists

The serotonergic regulation of feeding behaviour has not so far been studied in ruminants. Therefore, the effects of some serotonin (5-HT) receptor agonists and antagonists on food intake and forestomach motility were studied in dwarf goats.Goats ate less food when treated intravenously (IV) with the 5-HT precursor 5-HTP (25 µg, 50 µg or 100 µg kg^–1 min^–1 over 15 min) than when they were treated with 5-HT (which does not pass the blood-brain barrier) or with saline. Accordingly, IV dexfenfluramine infusions (50 µg or 100 µg kg^–1 min^–1 over 15 min), which induces release of brain 5-HT, also led to dose-related reductions in food intake. In contrast, no anorectic effects were observed after IV infusions with the selective 5-HT reuptake inhibitor fluoxetine (100 µg kg^–1 min^–1 over 15 min), the selective 5-HT1A agonist 8-OH-DPAT (0.5 µg kg^–1 min^–1 over 15 min), or eltoprazine (4 or 8 µg kg^–1 min^–1 over 15 min), a mixed 5-HT1A/5HT1B receptor agonist. None of the 5-HT antagonists tested gave any increase in food consumption in this model. Interestingly, the non-selective 5-HT receptor antagonist methysergide (360 µg/kg IV) reduced food intake. This effect was most noticeable at 3 h after injection. The 5-HT3 receptor antagonist ondansetron (IV 10 µg kg^–1 min^–1 over 15 min) and the peripheral 5-HT2 receptor antagonist xylamidine (IV 100 µg kg^–1 min^–1 over 10 min) failed to modify food intake. These results provide evidence for central serotonergic involvement in the control of feeding. However, this control system differs markedly in goats and rodents.Dexfenfluramine, 5-HTP and eltoprazine administered at similar dose rates to those used in the food intake experiments induced some clinical signs including inhibition of forestomach contractions. These results, together with our earlierin vivo andin vitro observations, suggest that the inhibitory effects of serotonin receptor agonists on forestomach contractions are due to interactions with both peripheral and central serotonergic receptors. The change in smooth muscle tension, which leads to a change in the signals transmitted via vagal afferents to the central nervous system, appears not to modify feeding behaviour in dwarf goats.     

REGIONAL BINDING INDEX OF THE RADIOLABELED SELECTIVE 5-HT2A ANTAGONIST 123I-5-I-R91150 IN THE NORMAL CANINE BRAIN IMAGED WITH SINGLE PHOTON EMISSION COMPUTED TOMOGRAPHY

The pattern of the specific 5-HT2A (5-hydroxytryptamine 2A receptor) antagonist 123I-5-I-R91150 was measured in 10 healthy dogs without neurologic and behavior abnormalities. Eight cortical regions (left and right fronto-, temporo-, parieto-, and occipitocortical area), one global subcortical region (including the thalamic system) were compared with a reference region lacking receptors; that is, the cerebellum. The 123I labeled radioligand was injected intravenously 100-200 minutes before acquisition. Both transmission and emission data were obtained with a triple head gamma camera equipped with high-resolution fanbeam collimators. The emission data were corrected for scatter and attenuation. To delineate different cerebral regions more accurately, the regions of interest (ROI) defined in a former study on brain perfusion measured with 99mTc-ethyl cysteinate dimer (ECD) in the same dogs were used. The co-registration of the 99mTc-ECD and the 123I-5-I-R91150, obtained from each dog, was realized with the help of corresponding transmission maps. By normalizing each regional cerebral activity to the activity observed in the cerebellum, the regional radioactivity (binding index) could be relatively quantified. Highest brain uptake was noted in the frontocortical brain areas (right: 1.85, left: 1.89), followed by the temporocortical region (right: 1.58, left: 1.56). Least uptake was noted in the more caudal and middle brain regions [occipito- (right: 1.46, left: 1.41), parietocortical (right: 1.30, left: 1.26), and striatal region (1.19)]. No gender nor age influence was noted in this series. The 123I labeled serotonin-2A receptor ligand seems to have similar cortical binding in the normal canine brain, as shown in humans and other animal species. A frontocortical to occipitocortical (rostrocaudal) binding index gradient was identified within the dog, which has not been seen in imaging studies from humans and other animal species. The significance of these results will need further investigation. This normative data can be used to compare regional brain uptake of the 123I-radioligand to dogs with behavioral disorders related to the serotonergic system, in future studies.     

Antinociceptive actions of intravenous a2-adrenoceptor agonists in sheep

The antinociceptive activity of the intravenously administered alpha 2-adrenoceptor agonists, clonidine and xylazine, was measured in sheep using thermal and mechanical pressure threshold detection systems. Both drugs demonstrated clear antinociceptive activity for both forms of threshold stimuli and clonidine at 6 micrograms/kg i.v. was more potent and longer lasting than xylazine at 50 micrograms/kg i.v. The antinociceptive effects were reversed by idazoxan (0.1 mg/kg i.v.), but were not affected by naloxone at 0.2 mg/kg i.v. indicating that these effects were mediated by alpha 2-adrenoceptors.     

The vascular responses of the isolated perfused bovine external ear to exogenous histamine and 5-HT (serotonin)

The responses of the vasculature of isolated, non-sensitized, bovine external ears to histamine and serotonin (5-HT) were evaluated while they were being perfused with Krebs-Henseleit solution, Histamine (10^–5 mol/L to 5×10^–3 mol/L) and 5-hydroxytryptamine (5-HT) (10^–9 mol/L to 10^–2 mol/L) caused increased vascular resistance. Mepyramine (10^–7 mol/L), cimetidine (10^–5 mol/L) and atropine (10^–6 mol/L) inhibited the responses to histamine. The responses to 5-HT were inhibited by methysergide (10^–9 mol/L) and potentiated by morphine (10^–5 mol/L). These results suggest the presence of H₁ and H₂ histamine, and 5-HT receptors in bovine auricular vessels, all of which cause net vasoconstriction.     

家禽动眼神经核簇的细胞构筑及其5-HT神经元的分布

用Nissi染色法和免疫组化SP法研究鸡、北京鸭、鸽子的动眼神经核簇细胞构筑及5-羟色胺神经元分布情况，结果表明：北京鸭的动眼神经核簇系由动眼神经核、E—W核和前背外侧核3个部分所构成，而在鸡和家鸽仅包括动眼神经核和E—W核。他们的核团形态和细胞构筑基本相同。观察到5-HT阳性神经元在鸡、鸭和鸽子动眼神经核及鸡E—W核内的分布，而在鸭和鸽子的E—W核和鸭的前背外侧核内却未见分布。动眼神经核5-HT阳性神经元的数量较多，在各个亚核的分布均匀，胞体着色较深。     

肺动脉高压肉鸡肺小动脉中膜5-HT量及其与肺血管重构的关系

静脉注射纤维素粒子复制肉鸡肺动脉高压模型,观察肺小动脉中膜5-羟色胺(5-HT)表达和肺小动脉管壁病理形态学变化,探讨5-HT与肺血管重构的关系。80羽科宝肉鸡分为对照组(n=30)和试验组(n=50)。20日龄时,试验组每羽鸡静脉注射0.3 mL的纤维素悬液;对照组每羽鸡静脉注射等体积生理盐水。记录肺动脉高压综合征(PHS)发病率,并分别于21、28、35、42 d从各组随机抽样,测定右心室/全心室质量比(RV/TV)、红细胞压积(PCV)、血红蛋白(Hb)、肺小动脉管壁面积/管总面积(WA/TA)、平均中膜厚度(mMTPA)和肺厚壁末梢血管百分比(TWPV%);采用免疫组化方法标记5-HT,并用病理图像分析软件检测肺小动脉5-HT的量。结果表明:试验组肉鸡PHS发病率显著高于对照组(P<0.05);RV/TV值在35、42 d时显著升高(P<0.05);PCV在28、35 d时显著升高(P<0.05);Hb值在35 d时显著升高(P<0.05);血管mMTPA、WA/TA和TWPV%在35、42 d时均显著升高(P<0.05);肺小动脉5-HT含量升高,在各时间点均差异显著(P<0.05),且5-HT含量...     

Antinociceptive activity of midazolam in sheep

The purpose of this study was to examine the effects of midazolam on the nociceptive threshold responses in sheep. The intravenous administration of midazolam (0. 1–0.3 mg/kg) produced a significant dose-dependent elevation of the mechanical and thermal nociceptive thresholds. The intravenous administration of flumazenil (20 μg/kg) markedly attenuated the antinociceptive activity of midazolam in the mechanical nociceptive test, whereas intravenous naloxone (0.2 mg/kg) had no significant effect on midazolam-mediated analgesia. The intrathecal administration of midazolam (1 mg), via chronically implanted cervical subarachnoid catheters, produced a significant elevation in the mechanical threshold responses. These results indicate that midazolam has antinociceptive actions in the sheep and suggest that this effect is, at least partially, mediated at the spinal level.     

高效液相色谱法测定猪血浆、全血和血小板中五羟色胺水平及其相关性分析

本试验采集43头苏淮猪的血液样本,探究利用高效液相色谱法(HPLC)测定血浆和全血五羟色胺(5-HT)的色谱条件,测定了血浆、全血和血小板中5-HT的水平,并对它们进行了相关性分析。结果:猪血浆中5-HT浓度为(45.35±2.23)μg/mL,血小板中5-HT含量为(131.31±7.86)pg/10^9,全血中5-HT浓度为(296.87±12.81)μg/mL;相关性分析显示,血小板5-HT浓度与全血5-HT浓度存在极显著正相关性(r=0.849,P<0.01),血小板5-HT浓度与血小板数量存在极显著负相关性(r=-0.549,P<0.01),但血浆5-HT浓度与全血5-HT浓度、血小板5-HT浓度无显著相关性(P>0.05)。综上,高效液相色谱法可用于测定猪血浆、全血、血小板中5-HT的水平,血小板5-HT含量与全血5-HT浓度和血小板数量之间均存在极显著相关性。     

The vasomotor effects of 5-hydroxytryptamine on equine basilar arteries In vitro

The vasomotor effects of 5-hydroxytryptamine (5-HT) on isolated equine basilar arteries were studied. 5-HT induced contractions of equine basilar arteries in a concentration-dependent manner, with a pEC₅₀ value (with 95% confidence limits) of 7.35 (7.08–7.62). Similar results were obtained with endothelium-denuded basilar arteries. Contractions were not competitively inhibited by the 5-HT₂ receptor antagonist ketanserin at low concentrations of 5-HT. Conversely, at high concentrations of 5-HT, contractions were inhibited by ketanserin in a concentration-dependent manner, with a pA ₂ value of 8.91 (8.62–9.20). The 5-HT₁ and 5-HT₂ receptor antagonist methiothepin shifted the concentration-response curve of 5-HT downwards and to the right in a concentration-dependent manner. In the presence of 10^-6 mol/L ketanserin, however, methiothepin antagonized 5-HT-induced contractions competitively with a pA ₂ value of 7.95 (7.59–8.31). The 5-HT₃ receptor antagonist MDL 72222 had no effect on 5-HT-induced contractions. The findings of this study indicate that 5-HT₁ and 5-HT₂ receptors are located in equine basilar arterial smooth muscle cells, and that stimulation of these receptors results in contraction.Abbreviations CR concentration ratio - EC₅₀ concentration producing 50% of the maximal response - 5-HT 5-hydroxytryptamine - MDL 72222 1H,3,5H-tropan-3-yl-3,5-dichlorobenzoate - pA ₂ negative logarithm of the molar concentration of antagonist that produces a 2-fold rightward shift of the concentration-response curve - pEC₅₀ negative logarithm of EC₅₀ - PGF₂ prostaglandin F₂     

5-羟色氨调控动物采食的研究进展

关于5-羟色氨(5-HT)对采食量的影响已有几十年的研究历史。机体内的5-HT主要是以必需氨基酸色氨酸(Trp)作为前体物,在大脑和肠道中合成,并在机体中发挥重要的作用。5-HT无法直接透过血-脑屏障,因此中枢神经系统和外周5-HT作为两个相对独立的系统各自发挥作用。目前,已有大量的研究表明中枢5-HT的多种受体以不同的方式调控动物采食,主要有5-HT1A、5-HT1B、5-HT2A、5-HT2C、5-HT3A、5-HT4、5-HT5A、5-HT6和5-HT7。例如,现在临床上被批准使用的抗肥胖药物氯卡色林就是一种5-HT2C受体激动剂。此外,中枢5-HT还可以协同胰高血糖素样肽-1、饥饿素和胆囊收缩素等外周激素共同调控动物采食行为。外周5-HT也能够通过介导胰高血糖素样肽-1和胆囊收缩素来诱导饱腹感。畜禽生产中主要通过在饲料中添加Trp来增加动物体内5-HT的合成。但目前对于Trp对畜禽采食量的调控机制的研究尚不完善,且有研究表明,不同浓度的Trp对动物采食量的影响不同,不同畜禽饲料中最适Trp的浓度也不同。而Trp主要是通过其代谢产物5-HT来调控动物采食。作者查阅了大量国内外最新的研究成果,从中枢和外周两个途径对5-HT调控动物采食行为的研究进展作一综述,期望通过对Trp的代谢产物5-HT对动物采食调控机制的探讨,为Trp在畜禽生产中的应用提供一定的理论依据。     

A retrospective study of efficacy and side effects of intrathecal administration of hyperbaric bupivacaine and morphine solution in 39 dogs undergoing hind limb orthopaedic surgery

ObjectiveTo evaluate the intraoperative efficacy of intrathecal anaesthesia with hyperbaric bupivacaine 0.5% and morphine 1% solution (HIA) in dogs undergoing hind limb orthopaedic surgery, using the cardiovascular response to surgical stimulation and to report the perioperative side effects.Study designRetrospective clinical study.AnimalsForty-three dogs that underwent general anaesthesia for hind limb orthopaedic surgery between 2010 and 2011.MethodsThe anaesthesia records of dogs that received HIA were reviewed. The bupivacaine and morphine doses were calculated based on body mass (BM) and spinal cord length (SCL). Cardiovascular response (CR) to surgical stimulation, the incidence of hypotension, bradycardia, urinary retention, pruritus and offset of motor block were all reported. The intraoperative time-to-event probability of CR was analyzed using Kaplan–Meier survival analysis.ResultsThe median (range) bupivacaine dose related to BM was 0.57 (0.40–0.78) mg kg^?1, while that related to SCL was 0.13 (0.08–0.19) mg cm^?1. A CR was observed in 3/39 (8%) dogs within the first hour after intrathecal injection (Ii) and in 9/39 (23%) dogs over the entire duration of surgery. At 70 minutes from Ii the event-free probability of CR fell below 80%. Hypotension was observed in 12/39 (31%), bradycardia in 6/39 (15%), pruritus in 3/39 (8%), and urinary retention in 3/39 (8%) dogs respectively. Five hours after Ii, 35/39 (89%) dogs were able to walk with only residual ataxia.Conclusions and clinical relevanceIntrathecal anaesthesia with hyperbaric bupivacaine 0.5% and morphine 1% solution provided effective intraoperative antinociception up to 70 minutes in dogs undergoing hind limb surgery. The technique of HIA can provide effective analgesia during short hind limb surgeries in dogs.     

Efficacy and side effects of intraoperative analgesia with intrathecal bupivacaine and levobupivacaine: a retrospective study in 82 dogs

ObjectiveTo evaluate spinal (intrathecal) anaesthesia (SA) in addition to general anaesthesia in dogs, and report the incidence of side effects and cardiovascular response (CR) to surgery.Study designRetrospective clinical study.AnimalsOne hundred and fifteen dogs undergoing general anaesthesia for surgery caudal to the diaphragm between 2005 and 2008.MethodsRecords of anaesthetized dogs that had received SA with bupivacaine or levobupivacaine 0.5%, together with morphine or fentanyl were reviewed. Success rate of SA, complication rate and incidence of CR were recorded and examined in relation to the dose of local anaesthetic administered and the type of surgery. Univariate and Cusum analysis were performed to identify independent predictors of response to surgical stimulation and characterize the learning curve for the technique, respectively.ResultsEighty-two dogs received successful SA. The Cusum plot suggested that a failure rate of 10% is achieved when the procedure is performed more than 66 times. Median local anaesthetic dose related to weight was 0.40 mg kg^?1 (0.3–0.5), and to spinal cord length 0.1 mg cm^?1 (0.07–0.12). Morphine was added to the local anaesthetic in 56 and fentanyl in 22 dogs. CR post-stimulus occurred in 29 cases: 11 of 22 ovariohysterectomies, 14 of 33 hindlimb-surgeries, 2 of 10 caudal-abdominal-surgeries and 2 of 17 Caesarean sections. Anaesthetic dose related to weight was not a predictor of CR. Bradycardia occurred in seven, hypotension in 24, urinary retention in four and hypersalivation in 6 of 82 dogs.ConclusionsSA was practicable to apply, but in this study did not totally block CR, Side effects were minimal, with an incidence similar to that in humans.Clinical relevanceSA can be used in clinical cases with few side effects although monitoring of and ensuing treatment of hypotension is required. Comparative prospective studies are required to establish efficacy and a reliable dose.     

Selective blockade of the responses of reticuloruminal muscle to 5-HT in sheep

The effects of intravenous administration of 5-HT on the patterns of reticulo-rumen contractions were studied in conscious sheep. Contractions were measured by strain gauges applied to the external wall of the reticulum and the ventral and/or dorsal sac of the rumen. The responses to 5-HT comprised (i) a short-lived contraction followed by (ii) a sustained increase in muscle tone and (iii) a concomitant inhibition of the extrinsic reticulo-rumen contractions. The corresponding blockades produced by (i) atropine, (ii) 5-HT antagonists and (iii) chemical sympathectomy suggest involvement of a peripheral cholinergic mechanism in the initial contractile response and a central adrenergic mechanism in the reflex inhibition of extrinsic reticulo-rumen contractions.