Chen Y F, Meng Q C
Department of Medicine University of Alabama, Birmingham 35294.
Life Sci. 1991;48(1):85-96. doi: 10.1016/0024-3205(91)90428-e.
Intact male and female spontaneously hypertensive rats showed a progressive increase in blood pressure with growth; male attained systolic blood pressure levels of 244 +/- 6 mmHg, and females 205 +/- 3 mmHg at age 22 weeks. Orchidectomy at age 4 weeks significantly attenuated the systolic blood pressure elevation in the male (195 +/- 4 mmHg at age 22 weeks), but ovariectomy at age 4 weeks had no effect on the development of hypertension in the female. The pattern of development of hypertension in orchidectomized males was the same as that in intact and ovariectomized females. Administration of testosterone propionate to gonadectomized rats of both sexes conferred a male pattern of blood pressure development. These results indicate that the sexually dimorphic pattern of hypertension in the spontaneously hypertensive rat is androgen dependent, rather than estrogen dependent. Plasma norepinephrine levels did not differ between the sexes, nor were they altered by gonadectomy or testosterone replacement, suggesting that the higher blood pressures in the intact male and androgen treated male and female SHR are not dependent on increased sympathetic outflow in the established phase of hypertension. Stores of norepinephrine in the posterior hypothalamic region were significantly greater in intact male rats and testosterone treated rats of both sexes than in intact or ovariectomized females, and were higher in the pons of intact female rats than in all other groups. These alterations in central catecholamine stores were not correlated with blood pressure. Further study is needed to assess the functional significance of these androgen mediated alterations in posterior hypothalamic neurons as a determinant of the androgen mediated sexual dimorphism of blood pressure in the spontaneously hypertensive rat.
完整的雄性和雌性自发性高血压大鼠血压随生长而逐渐升高；22周龄时，雄性大鼠收缩压达到244±6 mmHg，雌性大鼠达到205±3 mmHg。4周龄时进行睾丸切除可显著减轻雄性大鼠收缩压的升高（22周龄时为195±4 mmHg），但4周龄时进行卵巢切除对雌性大鼠高血压的发展没有影响。去势雄性大鼠的高血压发展模式与完整和去势雌性大鼠相同。对两性去势大鼠给予丙酸睾酮可呈现雄性血压发展模式。这些结果表明，自发性高血压大鼠中高血压的性别二态性模式是雄激素依赖性的，而非雌激素依赖性。两性之间血浆去甲肾上腺素水平没有差异，去势或睾酮替代也不会改变其水平，这表明完整雄性以及雄激素处理的雄性和雌性自发性高血压大鼠的较高血压在高血压确立阶段并不依赖于交感神经输出增加。完整雄性大鼠以及两性睾酮处理大鼠下丘脑后区的去甲肾上腺素储备显著高于完整或去势雌性大鼠，完整雌性大鼠脑桥中的去甲肾上腺素储备高于所有其他组。中枢儿茶酚胺储备的这些变化与血压无关。需要进一步研究以评估下丘脑后神经元中这些雄激素介导的变化作为自发性高血压大鼠雄激素介导的血压性别二态性决定因素的功能意义。
