外源性睾酮对高脂饮食去势雄兔冠状小动脉的影响

目的 了解外源性睾酮对高脂饮食去势雄免冠状小动脉的影响。方法 雄性新西兰白兔35只随机分成对照组、单纯去势组、低睾酮血症补充组、生理睾酮血症补充组和高睾酮血症补充组共5组，除对照组外其余各组行去势手术，术后对后3组肌注十一酸睾酮（TU），剂量分别是3，6，12mg／kg，形成低睾酮血症、生理水平睾酮血症、高睾酮血症，测定血清雌二醇（E2）、睾酮（T）水平和E2／T比值的变化，动物于第12周末处死．心肌切片染色，测定肌间小动脉硬化发生率、内膜增厚发生率、计算内膜面积占有率（RIA）、内膜／中膜比值。结果 肌间小动脉粥样硬化发生率、肌间小动脉内膜增厚率、RIA、内膜／中膜：对照组与生理睾酮血症补充组相当且均明显低于单纯去势组、低睾酮血症补充组和高睾酮血症补充组（P〈0．05）。结论 补充生理水平的外源性睾酮能降低高脂饮食去势雄兔的冠状小动脉粥样硬化发生率、肌间小动脉内膜增厚率、RIA，改善内膜／中膜比值，从而改善动脉粥样硬化。

Effects of exogenous testosterone on small coronary arteries in castrated cholesterol-fed rabbits

Objective To study the effect of intravenous testosterone on the small coronary arteries in castrated cholesterol-fed rabbits. Methods Thirty-five male New Zealand white rabbits were randomly allocated to 5 groups:(1)control group, (2)castrated group ,(3)small dosage(3mg/kg) intravenous testosterone and castrated group, (4)physiological dosage(6mg/kg) intravenous testosterone and castrated group, (5)large dosage(12mg/kg) intravenous testosterone and castrated group. All animals were fed with high cholesterol diet. At the end of the 12th week, the serum levels of testosterone (T), estrogen(E2), estrogen/ testosterone (E2/T) ratio were measured, and all rabbits were sacrificed by air embolism .Hearts were removed and kept in 10% formalin for a week. The ventricles were obtained for determination of the degree of arteriolosclerosis by computer image analysis system. The incidences of atherogenesis and intimal thickening and the ratio of the intimal area to total area (intimal area plus intraluminal area) and intimal/medial ratio were determined. Results The incidences of atherogenesis and intimal thickening and the ratio of the intimal area to total area (intimal area plus intraluminal area) and intimal/medial ratio were markedly more serious in groups 2,3,5 than those in groups 1 and 4 (P<0.05). Conclusions Intravenous testosterone at physiological dosage (6mg/kg) has beneficial effect on vascular endothelium and can decrease the incidences of atherogenesis and intimal thickening and the ratio of the intimal area to total area and intimal/medial ratio, thus benefiting the prevention of coronary artherosclerosis.