补肾方对自然衰老大鼠睾酮调节作用及机制研究

Regulatory effect of Bushenfang on the serum testosterone level of naturally aging rats and its mechanism

目的:探讨补肾方对自然衰老大鼠睾酮调节作用及机制,为临床治疗迟发性睾丸功能减退提供理论和实验依据。方法:将32只18月龄老年雄性SD大鼠随机分为4组,自然衰老模型组,补肾方低、中、高剂量组,每组8只;另选4月龄青年雄性SD大鼠8只作为正常对照。正常对照组、自然衰老模型组予生理盐水,补肾方低剂量、中剂量、高剂量组分别按生药量3.25、7.5、15.0 g/kg体重予中药复方连续灌胃,各组给药3周后处死。采用苏木精-伊红(HE)染色观察大鼠睾丸组织形态,放免法检测大鼠血清睾酮水平,RT-PCR法检测大鼠类固醇合成急性调节蛋白(StAR)、细胞色素胆固醇侧链裂解酶(P450 scc)、3β-羟类固醇脱氢酶Ⅰ(3β-HSDⅠ)mRNA的相对表达。结果:睾丸组织病理切片显示补肾方干预后大鼠睾丸间质细胞数目增多,补肾方低、中、高剂量组血清睾酮水平[(6.74±1.56)、(8.50±1.99)、(12.41±2.91)nmol/L]与自然衰老模型组[(3.48±0.75)nmol/L]比较显著提高(P<0.05),睾酮合成相关酶StAR、P450 scc、3β-HSDⅠmRNA相对表达(StAR:0.74±0.29、0.83±0.32、1.35±0.50;P450 scc:0.72±0.36、1.02±0.30、1.41±0.37;3β-HSDⅠ:0.58±0.14、0.72±0.07、0.85±0.18)与自然衰老模型组(StAR:0.44±0.09;P450 scc:0.33±0.05;3β-HSDⅠ:0.34±0.02)比较均提高,其中高剂量组StAR,中、高剂量组P450 scc、3β-HSDⅠ的表达与自然衰老模型组比较差异有显著性(P<0.05)。结论:改善睾丸组织衰老的病理状态,提高睾酮合成酶表达可能是补肾方调节自然衰老大鼠睾酮水平的作用机制。

Objective： To study the regulatory effect of Bushenfang on the serum testosterone （T） level of naturally aging rats and its mechanism, in order to provide a theoretical and experimental basis for the clinical treatment of late onset hypogonadism （LOH） in males. Methods： Thirty-two 18-month-old male SD rats were randomly divided into four groups of equal number, naturally aging model and low-, medium- and high-dose Bushenfang groups, and another eight 4-month-old rats were taken as normal controls. The rats of the aging model and normal control groups were treated with normal saline, while those of the low-, medium- and high-dose Bushenfang groups received intragastrically Bushenfang at 3.25, 7.50 and 15.00 g/kg, respectively, all for 3 weeks. Then the rats were sacrificed, the histomorphologic changes of the testis observed by HE staining, the serum T level measured by radioimmunoassay, and the expressions of the StAR protein, P450scc and 3 β-HSD Ⅰ determined by RT-PCR. Results ： The number of Leydig cells was obviously increased after Bushenfang treatment. The levels of serum T were significantly higher in the low-, medium- and high-dose Bushenfang groups （[6.74 ± 1.56] nmol/L, [8.50 ± 1.99] nmoL/L and [12.41± 2.911 nmol/L） than in the model group （ [ 3.48 ± 0.75 ] nmol/L） （P 〈 0.05 ）. The three Bushenfang groups also showed a remarkable elevation in the mRNA expressions of StAR （0.74 ± 0.29, 0.83 ±0.32 and 1.35 ± 0.50）, P450sce （0.72 ±0.36, 1.023 ±0.30 and 1.41 ±0.37） and 3β- HSD Ⅰ （0.58 ± 0.14, 0.72±0.07 and 0.85± 0.18）, as compared with the models （STAR： 0.44 ± 0.09; P450scc： 0.33 ± 0.05 ; 3β-HSD Ⅰ： 0.34 ± 0.02）, with significant differences in the StAR expression between the high-dose Bushenfang and the model groups, as well as in P450scc and 3 β-HSD Ⅰ expressions between the medium- and high-dose Bushenfang and the model groups （P 〈 0.05）. Conclusion ： Bushenfang could improve the pathological status of testicular injury and increase the expression of testosterone synthetase, which might be the mechanism behind its regulatory effect on the serum T level of aging rats.