Serotonin and sexual behavior in the male rabbit

Summary. Sexual behavior was evaluated in sexually experienced male rabbits after the administration of different serotonergic drugs. The serotonin_1A receptor agonist 8-OH-DPAT, 1 mg/kg, inhibited male rabbit sexual behavior when animals were tested 15 min after subcutaneous (SC) administration of this compound. Lower doses, 0.25 and 0.5 mg/kg, were ineffective at a test 30 min after drug injection. Furthermore, 8-OH-DPAT, 0.25 mg/kg, failed to revert the inhibitory effects upon sexual behavior produced by lidocaine application to the rabbit penis. Stimulation of 5-HT_1B/2C receptors by TFMPP, at doses between 0.625 and 2.5 mg/kg, produced a drastic inhibition of sexual behavior when the drug was administered SC 30 min before behavioral observation. Doses below 5 mg/kg were ineffective when given intraperitoneally 15 min before test. When the 5-HT_1D/2C receptors were stimulated by the agonist mCPP a reduced number of mounts and ejaculations was observed after the SC administration of 1.25 and 2.5 mg/kg. Similarly, the mixed 5-HT agonist/antagonist lisuride reduced the percentage of rabbits displaying mounting behavior at doses of 0.25 and 0.5 mg/kg SC. All compounds tested produced a clear inhibition of male rabbit sexual behavior independently of the receptor subtype activated. These results are at variance with previous observations in rats where 8-OH-DPAT and lisuride produced a drastic facilitation of masculine coital behavior. Moreover, while the inhibition of male sexual behavior in rats produced by TFMPP and mCPP is associated with a disruption of the execution of this behavior, in rabbits these compounds reduced sexual motivation. These results indicate that the effects of serotonergic drugs on sexual behavior are species specific. Received August 26, 1999; accepted November 4, 1999     

心房峡部L型钙电流特征的研究

目的研究心房峡部L型钙电流的特性,探讨心房峡部参与心律失常的机制。方法新西兰大白兔15只,麻醉后取心脏,灌流后分离右心房峡部及游离壁,利用全细胞膜片钳技术,对比观察心房峡部和右心房游离壁L型钙电流的电流密度,并观察异丙肾上腺素灌流后,其电流密度的变化。结果正常状态下,心房峡部和右心房游离壁L型钙电流的电流密度分别为-(7.03±0.71)pA/pF、-(6.30±0.61)pA/pF,二者比较差异无显著意义(P>0.05)。异丙肾上腺素灌流后,心房峡部和右心房游离壁L型钙电流的电流密度分别为-(11.01±0.46)pA/pF、-(8.51±0.31)pA/pF,两处的L型钙电流均显著增大,且心房峡部的L型钙电流密度显著大于右心房游离壁(P<0.01)。结论L型钙电流的异常变化可能是心房峡部参与心律失常发生机制的重要因素。     

超声对不同染毒剂量兔肾背向散射积分的研究

目的：探讨背向散射积分（IBS）技术描述不同剂量有机磷中毒兔肾改变的价值。方法：建立兔急性有机磷中毒动物模型，分别于染毒后1h和3h对四个不同剂量实验组及对照组行二维超声和IBS检查、二维超声观察肾回声，测量肾大小，IBS定量分析肾改变：结果：任一剂量组染毒后肾回声均无改变。随着剂量的增大和染毒时间的延长，肾体积、长径与对照组相比差异均有显著性意义（P〈0．05），体积的变化早于长径。染毒1h后，3．75mL／kg组和5．00mL／kg组肾皮质和髓质IBS％与对照组相比差异有显著性意义（P〈0．05）；染毒3h后，2．50mL／kg组、3．75mL／kg组和5．00mL／kg组肾皮质和髓质IBS％与对照组相比差异有显著性意义（P〈0．05）：结论：不同染毒剂量有机磷类化合物中毒兔肾IBS改变与其病理变化相关，超声检查可为诊断有机磷中毒肾损害提供依据     

兔实验性肝硬化模型及门静脉给药系统的建立

目的应用四氯化碳造成兔肝硬化模型,并建立动物门静脉给药系统。方法雄性新西兰大白兔给予皮下注射四氯化碳,每周两次,12周后检测肝脏病理改变及肝组织羟脯氨酸含量。通过小肠系膜静脉末端进行门静脉插管术,将导管引致动物腹部皮下,通过经皮穿刺方法进行门静脉给药。结果四氯化碳注射12周后,兔肝组织出现典型的假小叶,肝组织羟脯氨酸含量较正常组升高3.5倍以上。门静脉给药系统可在体内维持达12周,但接头在体内易于老化破损。结论应用四氯化碳皮下注射方法成功地建立了一种兔肝硬化动物模型,并建立了一种经济简便的动物门静脉给药体系。     

Percutaneous toxicokinetic and repeated cutaneous contact studies with ethylene glycol monohexyl ether

Ethylene glycol monohexyl ether (EGHE; CAS no. 112-54-4) is a liquid industrial chemical with a potential for skin contact. The toxicokinetics of EGHE was investigated in Fischer 344 rats and New Zealand White rabbits by intravenous (i.v.) and 48-h occluded epicutaneous dosing. Given i.v. to male rats (2.5-25 mg kg(-1)) [(14)C]EGHE demonstrated fi rst-order kinetics. Carbon-14 was eliminated mainly in urine (68-74%) as metabolites, with no free EGHE. The plasma free EGHE concentration declined rapidly post-dosing and was not detectable by 8 h. Similar results were obtained for [(14)C]EGHE given i.v. to male rabbits in the dosage range 1-10 mg kg(-1), except that the metabolism of EGHE was more rapid, with no free EGHE being detectable in plasma by 1 h post-dosing. After cutaneous dosing of male and female rats with 25 mg kg(-1), there was rapid percutaneous absorption, with >95% of the radiochemical dose being recovered. Percutaneous bioavailability was >75%. Carbon-14 was excreted in urine (21-33%) to a lesser extent than by the i.v. route, and (14)CO(2) and volatiles accounted for 15-18%. Carbon-14 recovery was low from tissues and organs (0.39-0.46%), with no preferential accumulation. Extensive metabolism was indicated by the rapid decline in plasma free EGHE, with none being detectable by 48 h. Free EGHE was not present in urine, and urinary radioactivity was associated with up to seven metabolites. After cutaneous dosing of male and female rabbits (10 mg kg(-1)) ca. 75% of the dose was recovered, most (14)C being in urine (58-60%). Urine radioactivity was associated with up to nine metabolite peaks, but no free EGHE. The toxicokinetic findings indicate a significant percutaneous absorption of EGHE across both rat and rabbit skin, which is rapidly and extensively metabolized, with renal excretion being the principal route of elimination of metabolites. A 9-day repeated skin contact study in the male and female New Zealand White rabbit, using a dosage range of 44-444 mg kg(-1) day(-1), did not show any evidence for percutaneous systemic toxicity.     

头孢唑林对阿米卡星在兔体内的药动学影响

采用微量微生物法对阿米卡星（ＡＭＫ）单用及与头孢唑林（ＣＥＺ）合用后兔体内ＡＭＫ血药浓度进行测定,药时数据用ＭＣＰＫＰ软件经ＩＢＭ 计算机处理,并对两组药动学参数进行了统计学处理,结果表明ＣＥＺ对ＡＭＫ的药动学有显著的影响。     

日本大耳白兔自发子宫内膜癌1例病理组织学及超微结构观察

本例日本大耳白兔自发子宫内膜癌属腺癌。光镜下癌细胞排列呈腺管状 ,腺腔大小不等 ,胞质少 ,核大 ,癌细胞已侵袭至肌层。电镜下癌细胞呈长椭圆形及不规则形 ,线粒体、粗面内质网较少或无 ,且二者均发生肿胀 ;某些细胞内可见少量初级溶酶体 ;细胞核大且大小不一 ,核膜多凹陷 ;核仁呈网眼状。     

Pharmacokinetics and tissue distribution of idarubicin and its active metabolite idarubicinol in the rabbit

 A three-compartment model was fitted to idarubicin data in a NONMEM pooled-data approach. Clearance (CL) of 221.7 ml/min was relatively high, and drug distribution was rapid (CL_D=248.3 ml/min) and extensive [steady-state volume of distribution (V_ss) 24 l]. The area under the concentration-time curve (AUC) of idarubicinol was 8 times that of idarubicin. Concentrations of idarubicin (idarubicinol) measured in the myocardium at 24 h after i.v. administration of idarubicin were 20 (5) times those determined in plasma. Tissue concentrations of idarubicinol were up to 400 times those of idarubicin, indicating that the active metabolite contributes significantly to the overall drug action. Received: 16 June 1996 / Accepted: 4 November 1996     

肩痛散通电加热外敷治疗实验性兔肩关节周围炎的相关生物化学指标观察

作者以肩痛散通电加热外敷治疗实验性兔肩周炎，并测定了模兔患肩肌腱组织中的羟脯氨酸、ＤＮＡ和蛋白质，结果治疗组三种测定指标含量在治疗各时相均与健侧无明显差异。     

Na/K-ATPase in rabbit paranasal sinus mucosa during induced sinusitis

Summary Sinusitis was produced in rabbits, after which animals were separated into three groups: allergic sinusitis, induced purulent sinusitis, and spontaneous purulent sinusitis. Mucosal specimens were taken from these animals and normal controls. Na/K-ATPase was localized cytochemically and its activity studied in order to define the energy metabolism of secretion. The Na/K-ATPase reaction was unable to be clearly distinguished in either the allergic sinusitis specimens or the normal mucosa. In both purulent sinusitis groups, an intensive reaction was observed in the subepithelial glands and a weak reaction was found in the goblet cells. The Na/K-ATPase activity in the purulent sinusitis groups was significantly higher than that in the normal control group. The increased Na/K-ATPase activity may be an affect of hyperactivity of the secretory cells. Offprint requests to: M. Miyaguchi, Department of Otolaryngology, Kagawa Medical School, 1750-1 Miki-cho Kita-gun, Kagawa 761-07, Japan