疾病诱导大鼠α-肾上腺素能受体介导的心脏和血管反应的变化。

Disease-induced changes in alpha-adrenoceptor-mediated cardiac and vascular responses in rats.

Brown L, Amos G, Miller B

Department of Physiology and Pharmacology, University of Queensland, Australia.

Clin Exp Pharmacol Physiol. 1994 Sep;21(9):721-8. doi: 10.1111/j.1440-1681.1994.tb02575.x.

Abstract

The physiological relevance of cardiac and vascular alpha-adrenoceptors may increase in disease states in which beta-adrenoceptors are altered. To test this, positive inotropic and vasoconstrictor responses to phenylephrine were measured in isolated tissues from rats with experimentally-induced hyperthyroidism, hypothyroidism and diabetes as well as in genetically spontaneous hypertensive rats (SHR). 2. In left atria, positive inotropic responses to phenylephrine were increased in hypothyroid and diabetic rats and abolished in hyperthyroid and SHR. 3. In contrast, phenylephrine produced increased positive inotropy in left ventricular papillary muscles from hyperthyroid rats, increased potency in diabetic rats and negative inotropic responses in hypothyroid rats. 4. The potency of phenylephrine as a vasoconstrictor in thoracic aortic rings was increased in hyperthyroid and SHR and decreased in hypothyroid rats. 5. Thus, disease states which alter beta-adrenoceptor responsiveness can independently regulate atrial, ventricular and vascular responses to the alpha 1-adrenoceptor agonist, phenylephrine. Therefore, these disease states may alter the physiological control of the cardiovascular system by noradrenaline and adrenaline as well as the responsiveness in disease states to therapeutic agents acting via alpha-adrenoceptors.

摘要

在β-肾上腺素能受体发生改变的疾病状态下，心脏和血管α-肾上腺素能受体的生理相关性可能会增加。为了验证这一点，对实验性诱导的甲状腺功能亢进、甲状腺功能减退和糖尿病大鼠以及遗传性自发性高血压大鼠（SHR）的离体组织，测量了对去氧肾上腺素的正性肌力和血管收缩反应。2. 在左心房，甲状腺功能减退和糖尿病大鼠对去氧肾上腺素的正性肌力反应增强，而甲状腺功能亢进和SHR大鼠则消失。3. 相反，去氧肾上腺素使甲状腺功能亢进大鼠左心室乳头肌的正性肌力增加，糖尿病大鼠的效力增强，甲状腺功能减退大鼠则产生负性肌力反应。4. 去氧肾上腺素作为胸主动脉环血管收缩剂的效力在甲状腺功能亢进和SHR大鼠中增加，而在甲状腺功能减退大鼠中降低。5. 因此，改变β-肾上腺素能受体反应性的疾病状态可独立调节心房、心室和血管对α1-肾上腺素能受体激动剂去氧肾上腺素的反应。因此，这些疾病状态可能会改变去甲肾上腺素和肾上腺素对心血管系统的生理控制，以及疾病状态下对通过α-肾上腺素能受体起作用的治疗药物的反应性。