Etgen A M, Petitti N
Department of Psychiatry, Albert Einstein College of Medicine, Bronx, New York 10461.
J Neurochem. 1987 Dec;49(6):1732-9. doi: 10.1111/j.1471-4159.1987.tb02430.x.
Adrenergic receptor agonists and antagonists were employed to establish (a) which receptor subtypes mediate the cyclic AMP response to norepinephrine in hypothalamic and preoptic area slices from gonadectomized female rats and (b) which receptor subtypes might be modulated by the steroid hormone estradiol. Slice cyclic AMP levels were elevated by the beta receptor agonist isoproterenol, but not by alpha 1 (phenylephrine, methoxamine) or alpha 2 (clonidine) agonists. However, the alpha agonist phenylephrine potentiated the effect of the beta agonist isoproterenol on slice cyclic AMP accumulation. In slices from rats given no hormone treatment, the beta antagonist propranolol inhibited norepinephrine-stimulated cyclic AMP production, while the alpha 1 antagonist prazosin was without effect. In contrast, the cyclic AMP response to norepinephrine in slices from estradiol-treated rats was blocked more effectively by prazosin than by propranolol. Estradiol treatment also attenuated the production of cyclic AMP by the beta agonist isoproterenol. The data suggest (a) that norepinephrine induction of cyclic AMP accumulation in hypothalamic and preoptic area slices is mediated by beta receptors and potentiated by alpha receptor activation and (b) that estradiol depresses beta and increases alpha 1 receptor function in slices from brain regions associated with reproductive physiology.
(a) 哪些受体亚型介导去势雌性大鼠下丘脑和视前区切片中去甲肾上腺素引起的环磷酸腺苷（cAMP）反应；(b) 哪些受体亚型可能受到甾体激素雌二醇的调节。β受体激动剂异丙肾上腺素可提高切片中的cAMP水平，但α1受体激动剂（去氧肾上腺素、甲氧明）或α2受体激动剂（可乐定）则不能。然而，α受体激动剂去氧肾上腺素可增强β受体激动剂异丙肾上腺素对切片cAMP积累的作用。在未接受激素处理的大鼠的切片中，β受体拮抗剂普萘洛尔可抑制去甲肾上腺素刺激的cAMP生成，而α1受体拮抗剂哌唑嗪则无此作用。相反，在雌二醇处理的大鼠的切片中，哌唑嗪比普萘洛尔更有效地阻断了对去甲肾上腺素的cAMP反应。雌二醇处理还减弱了β受体激动剂异丙肾上腺素引起的cAMP生成。这些数据表明：(a) 下丘脑和视前区切片中去甲肾上腺素诱导的cAMP积累是由β受体介导的，并由α受体激活增强；(b) 在与生殖生理相关的脑区切片中，雌二醇会抑制β受体并增强α1受体功能。
