Regional variations in intramyocellular lipid concentration correlate with muscle fiber type distribution in rat tibialis anterior muscle.

1H MR spectroscopy (MRS) has proved to be a valuable noninvasive tool to measure intramyocellular lipids (IMCL) in research focused on insulin resistance and type II diabetes in both humans and rodents. An important determinant of IMCL is the muscle fiber type, since oxidative type I fibers can contain up to three times more IMCL than glycolytic type II muscle fibers. Because these different muscle fiber types are inhomogeneously distributed in rodent muscle, in the present study we investigated the distribution of IMCL within the rat tibialis anterior muscle (TA) in vivo using single-voxel 1H MRS along with the muscle fiber distribution in the TA ex vivo determined from immunohistological assays. IMCL levels in the TA differed by up to a factor of 3 depending on the position of the voxel. The distribution of IMCL over the TA cross section was not random, but emerged in a pattern similar to the distribution of the predominantly oxidative muscle fiber types. Dietary interventions, such as high-fat feeding and 15 hr of fasting, did not significantly change this typical fiber type-dependent pattern of IMCL content. These results stress the importance of voxel positioning when single-voxel 1H MRS is used to study IMCL in rodent muscle.     

Angular bundle kindling is accelerated in rats with a genetic predisposition to acoustic stimulus-induced seizures

Limbic kindling was examined in genetically epilepsy-prone (GEPR) and non-epileptic control rats. The early stage of kindling development was accelerated in both groups of GEPR rats compared to controls. Later stages of kindling were accelerated in GEPR-9 but not GEPR-3 rats. These results indicate that GEPR rats have an enhanced susceptibility to limbic kindling and suggest that limbic brain alterations may contribute to acceleration of the early stage kindling development in GEPR rats.     

炙甘草汤对大鼠室性早搏拮抗作用实验研究

目的：观察炙甘草汤对鸟头碱所致大鼠室性早博的预防和治疗作用。方法：成年SD大鼠50只，随机分为炙甘草汤大剂量组、中剂量组、小剂量组、生理盐水组、普萘洛尔组分别用相应药物及生理盐水灌胃5天后，匀速舌下静脉注射乌头碱，与生理参数分析仪相连接，观察心律失常的潜伏期及持续时间。结果：延长室性早搏的潜伏期炙甘草汤高、中剂量组与生理盐水纽比较有显著性差异（P〈0．05），普萘洛尔组与炙甘草汤高、中剂量组比较无显著性差异（P〉0．05）。缩短室性旱搏持续时间炙甘草汤高剂量组与生理盐水组比较有极显著差异（P〈0．01），炙甘草汤中剂量组与生理盐水组比较有显著性差异（P〈O．05），普萘洛尔组与炙甘草汤高、中剂量组比较无显著差异（P〉0．05），与生理盐水比较有极显著差异（P〈0．01）。结论：炙甘草汤对乌头碱所致大鼠室性早搏有一定的预防及治疗作用。     

平痫冲剂对戊四唑致痫大鼠海马氨基酸类神经递质受体的影响

目的通过免疫组织化学方法分析平痫冲剂对戊四唑（PTZ）致痫大鼠海马氨基酸类神经递质受体的影响，探讨其抗癫痫的作用机理。方法将60只28日龄的Wistar大鼠随机分为正常对照组（A组）、模型组（B组）、苯巴比妥组（c组）及平痫冲剂小（D组）、中（E组）、大（F组）剂量组。除正常对照组外，其余各组大鼠腹腔注射PTZ复制慢性癫痫模型，通过免疫组织化学方法和显微图像分析技术分别检测各组大鼠海马CA1、CA3的谷氨酸受体（NMDARI）和γ-氨基丁酸受体（GABA-ARα1）免疫反应的阳性细胞数（n）、阳性细胞面积比（Aa％）及阳性细胞积分吸光度（IA）。结果与A组比较，B组海马CA1、CA3等部位NMDAR1的n、Aa％上升，IA增加（P〈O．01）；与B组比较，c组及D、E、F组不同部位NMDARI的n、Aa％~-不同程度下降，IA也有不同程度减少（P〈0．05）。同A组比较，B组海马CA1、CA3等部位GABA-ARα，的11、Aa％下降，IA降低（P〈0．01）；与B组比较，C、D、E、F组不同部位GABA—ARα，的n、Aa％都有不同程度增加，IA也有不同程度升高（P〈0．05）。结论平痫冲剂抗癫痫的作用机理可能是通过抑制海马兴奋性神经递质受体NMDAR1的活性与表达，并激活其抑制神经递质受体GABA-ARα，的活性与表达，从而降低大脑皮质的兴奋性，有效抑制癫痫的形成及发展。     

氟伐他汀对糖尿病肾病大鼠足细胞分布及排泄的影响

目的探讨氟伐他汀对DN大鼠足细胞分布及排泄的影响。方法将大鼠分为3组：对照组、DN模型组、氟伐他汀治疗组。腹腔注射链脲菌素（STZ）诱导DN大鼠模型。实验10周末测24小时尿蛋白定量（TP）、血清总胆固醇（TC），间接免疫荧光法检测尿沉渣足细胞特异性标志蛋白podocalyxin（PCX）以检测尿液足细胞（UPC）水平；免疫荧光染色观察肾小球上皮细胞蛋白-1（GLEPP1）的分布。结果DN模型组UPC、TP、TC较对照组均明显升高；氟伐他汀治疗组TC、UPC及TP较DN模型组均降低；对照组GLEPP1正常、DN模型组呈节段性明显缺失、氟伐他汀治疗组缺失较轻。UPC与TP呈正相关，与TC无显著相关性。结论尿液中脱落足细胞检测可作为判断DN病情活动性的标志之一。氟伐他汀可减轻DN大鼠尿蛋白、降低胆固醇、减少足细胞脱落及排泄。     

两种隐匿阴茎大鼠模型的建立及比较

目的:建立稳定的大鼠隐匿阴茎模型,为探索阴茎包埋对海绵体结构和功能的影响提供实验动物模型。方法:90只2周龄雄性SD大鼠随机均分为A、B、C3组,A组采用阴茎根部内荷包缝合法,B组采用包皮折叠缝合法包埋阴茎,C组为假手术组。在180d内观察两种方法的包埋效果。结果:A组术后4只死于急性尿潴留,5只因尿道口周围软组织感染、皮肤破溃导致包埋失败,3只因包埋过松阴茎伸出;B组术后1只死于麻醉,2只死于急性尿潴留;因阴茎发育和勃起,A组有7只、B组有10只阴茎伸出;C组1只死于麻醉。A组和B组中其余大鼠均有较好的包埋效果,A组包埋成功率为36.7%,B组为56.7%,而且可以在实验中任何时候解除包埋。结论:包皮折叠缝合法和阴茎根部内荷包缝合法均能建立稳定的、且与人类隐匿阴茎自然病程较为一致的2周龄大鼠隐匿阴茎动物模型。     

背根神经节内P物质、降钙素基因相关肽免疫阳性神经元与阴茎包皮系带感觉信息的传递

目的:探讨背根神经节(DRG)内P物质(SP)、降钙素基因相关肽(CGRP)免疫阳性神经元与阴茎包皮系带感觉信息传递之间的关系。方法:通过荧光金(FG)逆行标记对大鼠阴茎包皮系带内神经末梢的来源作追踪定位,并结合SP、CGRP免疫荧光标记法,研究大鼠DRG内FG标记阳性神经元中SP、CGRP免疫阳性神经元的形态和分布。结果:FG逆行标记结果发现,大鼠阴茎包皮系带内的神经末梢起源于第6腰髓对应的背根神经节(L6-DRG)和第1骶髓对应的背根神经节(S1-DRG)的神经元。对这些神经元分别作SP、CGRP免疫荧光标记后发现,标记细胞大小不等,分别呈深红色和深绿色,沿神经束成行排列或散在分布。FG/SP、FG/CGRP双标记阳性细胞均为中小型,其数量分别占FG逆行标记阳性细胞总数的1/3和1/2,FG/SP/CGRP三标记阳性细胞占FG逆行标记阳性细胞总数的1/5。结论:大鼠L6-DRG和S1-DRG内的SP、CGRP免疫阳性神经元可能参与阴茎包皮系带感觉信息的传递。     

仙人掌粉对糖尿病大鼠血糖的影响

目的　研究仙人掌对糖尿病血糖的影响。方法　采用四氧嘧啶造成大鼠实验性糖尿病模型 ,然后将高、中、低 3种剂量的仙人掌粉加入到基础饲料中进行实验观察。结果　仙人掌粉高 (10g kg·d)、中 (5 .0g kg·d)剂量组均可显著降低糖尿病大鼠空腹血糖 ,并且高剂量组具有显著改善糖尿病大鼠尿量增加的作用。各剂量组对正常大鼠血糖无明显影响。结论　仙人掌粉能有效降低四氧嘧啶所导致的糖尿病大鼠的血糖、尿量     

Melatonin‐evoked potentiation of the juvenile rat tail artery neurogenic reactivity depends on degree of the change in the reactivity

Aim: Dependence of the melatonin‐evoked potentiation of the rat tail artery neurogenic reactivity on degree of the change in the reactivity was studied. Method: Electrical field stimulation‐evoked contractile response of the juvenile rat tail artery segment under isometric conditions was recorded. 0.1 μm melatonin was administered after the change in the response produced both spontaneously and by acidification (pH 6.6) or alkalinization (pH 7.8) of the solution. Results: During the course of experiment, the contraction force continuously declined, being reduced by 12 ± 5, 24 ± 7 and 32 ± 6% at 20, 70, and 170 min after beginning of experiment, respectively. Melatonin applied at these time points increased the contraction by 20 ± 5, 41 ± 10, and 48 ± 8%, respectively, relative to control. This increase in potentiating effect of melatonin during the course of experiment was not because of sensitization of the segment to the hormone. Acidosis‐induced considerable decline in neurogenic contraction was counteracted by melatonin, while after alkalosis‐induced augmentation in the contraction the hormone was not effective. Melatonin increased the artery response to 0.1 μm noradrenaline. Conclusion: These data suggest that melatonin can restore an attenuated neurogenic reactivity of the juvenile rat tail artery. The effect is more pronounced with further decrease in reactivity and might be due to a change in sensitivity of the post‐junctional membrane to noradrenaline.     

大鼠肝移植的麻醉

目的研究氯胺酮在大鼠肝移植中的合适剂量.方法对100只雄性Wister大鼠行40例肝移植,观察供受体麻醉过程、药物剂量和效果. 结果供体手术氯胺酮麻醉的剂量以100～125 mg/kg合适,受体手术氯胺酮麻醉的剂量以75～100 mg/kg合适.结论在大鼠肝移植的手术中,氯胺酮是一种理想的麻醉药品.