[Various physiological mechanisms of regulation of incorporation of H3-noradrenaline into the adrenal glands of rats].

It was revealed on the isolated adrenal glands of rats that an increase of noradrenaline-3H concentration in the incubation medium was accompanied by the elevation of the KM (Machaelis' constant) and Vmakc (V maximum) amine uptake parameters. A simultaneous elevation of the KM and Vmakc leads that the efficacy (E) of the uptake altered much less than the main parameters. The revealed dependency between the substrate concentration in the medium and the rate of noradrenaline uptake was apparently caused by the heterogeneity of the system reserving catecholamines in the medullary layer of the adrenal glands. It was shown that under the effect of phentholamine (2-5.10(-7) M) the alpha-adrenoceptor blockers, and propranolol (2-5.10(-7) M) the uptake of noradrenaline-3H by rat adrenal glands became activated. However, with the action of urea (5.10(-3)--1.10(-2) M) an activator of alpha-receptors, and of isopropylnoradrenaline (5.10(-7)--5.10(-6) M), and activator of beta-adrenocereceptors, the rate of noradrenaline-3H uptake was decreased. It is supposed that one of the ways of regulation of noradrenaline accumulation in the adrenal glands was connected with the heterogeneity of the reserving catecholamine system, and another one--with the changes in the functional condition of the adrenal gland cell adrenoceptors.