РОЛЬ ПАРАТИРЕОИДНОГО ГОРМОНА В ФУНКЦИОНАЛЬНОЙ АКТИВНОСТИ СЕРДЕЧНО-СОСУДИСТОЙ СИСТЕМЫ

Abstract

A comprehensive comparative study of the contractile ability of aorta and systemic hemodynamic responses has been performed in animals with impaired calcium-phosphorus metabolism, caused by removing the parathyroid glands and under the influence of parathyroid hormone (PTH). In addition, the analysis of its pharmacological mechanism of action has been performed. The results of aorta contractility in vitro studies in control and parathyreoidectomied rats as well as under the influence of PTH physiological concentrations (10-10 M), L-blocker of Са-channels of myocyte membrane - verapamil (10-5 M) and a phosphodiesterase inhibitor - theophylline (10-4 M) demonstrated the possible regulatory impact of PTH and related disorders to reduce the aorta contractility induced by adrenaline (10-5 M) and its relaxation caused by papaverine (10-4 M). Further, in vivo studies revealed that the increase of heart rate (HR) and the decrease of blood pressure (BP) in rats with impaired calcium-phosphorus metabolism is caused by the parathyroidectomy. Special attention should be paid to the fact that we have observed increased reactivity of aortic myocytes in parathyreoidectomied animals in response to the action of adrenaline and papaverine, as well as a sharp increase in adrenoreactivity of heart and blood vessels, thus the increase in HR and BP in response to the usual doses of adrenaline. The clinical significance of this phenomenon is undeniable. The possibility of a sharp increase of BP in patients with PTH-dependent disturbance of calcium-phosphorus metabolism and the potential of development of severe vascular complications (strokes, heart attacks) in the context of emotional and stress influences should be considered in clinically similar conditions.