睾酮对大鼠心肌梗塞后心肌肥大的影响

Effect of testosterone on myocardial hypertrophy and cardiac function after myocardial infarction in rats

本文应用立体形态定量技术,观察睾酮(T)对心肌梗塞后心肌肥大的影响。实验分为:假手术组(S组)、心肌梗塞组(MI组)。心肌梗塞后睾酮治疗组(MIT组)。结果证明,与S组相比,MI及MIT组大鼠心肌细胞核密度明显减少,尤其以MIT组变化显著,MIT组平均核长度明显增加;MI组的+dp/dt max明显降低,T值延长,MIT组的上两指标无显著差异。MI后血浆T总浓度与平均每核心肌细胞体积呈显著正相关关系。提示:睾酮确实促进了MI后心肌肥大,从而促进了心功能的恢复。

To determine the effects of testosterone (T) on hypertrophy and cardiac function of rats with myocardial infarction (MI), the rats were divided into 3 groups: ie, the sham-operated group (S group), the coronary artery ligating groups with or without the injection of T (MIT and MI group). T level of plasma was tested on all rats, by RIA on1/4, 1, 3, 9, 20 day after operation; then the nuclear profiles per unit area of myocardium N_((n)A) the average nuclear length D_((n)) and the volume fraction of number of myoeytes in the myoeardium V_((m)v) were measured under microscope; The number of myocyte nuclei per unit ovolume of myocardium N_((n)v) and average myocyte cell volume per nucleus V_((m)n) were calculated. The results were as follows: (1) Comparing with S group N_((n)A), N_((n)v) and V_((m)n) in MI had marked changes (P<0.01) while D_((n)) of the MI group increased insignificantly (P>0.05). Of all the mentioned changes were more marked in MIT group than that in MI group. (2) The total plasma concentration of T was correlated with V_((m)n) (r=0.60, P<0.01). (3) Compared with S group. +dp/dt max was reduced (P<0.05) while T value was prolonged (P<0.05) in MI group, but notable different (P>0.05) were not found in MIT rats. These results indicated that T may improve myocardial hypertrophy and promote the recovery of eardial function of MI.