Kumai T, Tanaka M, Watanabe M, Nakura H, Kobayashi S
Department of Pharmacology, St Marianna University School of Medicine, Kawasaki, Japan.
Hypertension. 1995 Jul;26(1):208-12. doi: 10.1161/01.hyp.26.1.208.
We investigated the effects of castration and testosterone propionate on tyrosine hydroxylase mRNA, its activity, and catecholamine synthesis in the adrenal medulla of spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY). Four-week-old male rats were castrated. Testosterone propionate (500 micrograms per rat) was administered subcutaneously twice a week to castrated rats (between 14 and 25 weeks of age). Systolic pressure was measured at the age of 25 weeks, and rats were decapitated. The systolic pressure of castrated SHR was significantly lower than that of control and testosterone-replaced SHR. Epinephrine and norepinephrine levels, tyrosine hydroxylase activity, and tyrosine hydroxylase mRNA in the adrenal medulla of castrated SHR were significantly lower than in control and testosterone-replaced SHR. Systolic pressure and epinephrine and norepinephrine levels, tyrosine hydroxylase activity, and tyrosine hydroxylase mRNA levels in the adrenal medulla of WKY showed no significant differences among the control, castrated, and testosterone-replaced groups. These results suggest that androgens contribute to the development and maintenance of hypertension in SHR via sustained enhancement of tyrosine hydroxylase synthesis in the adrenal medulla, leading to increased epinephrine and norepinephrine levels.
我们研究了去势及丙酸睾酮对自发性高血压大鼠（SHR）和Wistar-Kyoto大鼠（WKY）肾上腺髓质中酪氨酸羟化酶mRNA、其活性以及儿茶酚胺合成的影响。对四周龄雄性大鼠进行去势。每周两次皮下注射丙酸睾酮（每只大鼠500微克）给去势大鼠（14至25周龄）。在25周龄时测量收缩压，然后将大鼠断头。去势SHR的收缩压显著低于对照组和补充睾酮的SHR。去势SHR肾上腺髓质中的肾上腺素和去甲肾上腺素水平、酪氨酸羟化酶活性以及酪氨酸羟化酶mRNA均显著低于对照组和补充睾酮的SHR。WKY的收缩压、肾上腺素和去甲肾上腺素水平、酪氨酸羟化酶活性以及肾上腺髓质中的酪氨酸羟化酶mRNA水平在对照组、去势组和补充睾酮组之间无显著差异。这些结果表明，雄激素通过持续增强肾上腺髓质中酪氨酸羟化酶的合成，导致肾上腺素和去甲肾上腺素水平升高，从而促进SHR高血压的发生和维持。
