RESUMO
Introduction to the diet of adult (7-8 months) and old (24-26 months) male rats for 30 days after a single R-irradiation at a dose of 5 Gy of preparation "Korargin" (whose active ingredients are L-arginine, contributing to the prevention of endothelial dysfunction, and inosine) in old irradiated rats significantly increased the relaxation of isolated segments of thoracic aorta by the action of acetylcholine, sodium nitroprusside and insulin. In adults irradiated animals this effect was not observed. Vasoconstriction response of isolated segments of thoracic aorta to norepinephrine was decreased in isolated segments of thoracic aorta by adults and old irradiated rats compared with controls, and application of korargin had no significant effect. Thus, in old irradiated rats, in contrast to adult irradiated animals, the use of korargin increased of vascular sensitiveness to act of endothelial-dependent and endothelial-nondependent vazodilatators, helped to preserve of endothelial function and increase the capacity of vazodilatator potential.
Assuntos
Aorta Torácica/efeitos dos fármacos , Arginina/farmacologia , Endotélio Vascular/efeitos dos fármacos , Inosina/farmacologia , Vasoconstrição/efeitos dos fármacos , Vasodilatação/efeitos dos fármacos , Acetilcolina/farmacologia , Administração Oral , Fatores Etários , Animais , Aorta Torácica/metabolismo , Aorta Torácica/efeitos da radiação , Endotélio Vascular/metabolismo , Endotélio Vascular/efeitos da radiação , Raios gama/efeitos adversos , Insulina/farmacologia , Masculino , Nitroprussiato/farmacologia , Norepinefrina/farmacologia , Ratos , Ratos Wistar , Técnicas de Cultura de Tecidos , Irradiação Corporal TotalRESUMO
Studies were made of the effects of various classes of lipoproteins (LP) from the blood of rabbits with experimental hypercholesterolemia and human subjects with pronounced atherosclerosis on the vascular tone of rat thoracic aorta specimens. In hypercholesterolemia, there was a considerable weakening of a vasodilatory action of atherogenic LP fractions--LDL and VLDL. A vasodilatory effect of HDLP was not changed. In subjects suffering from atherosclerosis vasodilatory effects of both atherogenic and antiatherogenic HDLP decreased significantly. The revealed changes were related to shifts in lipid and protein components of LP complexes manifesting in the development of dyslipoproteinemia and dysapoproteinemia. In atherosclerosis accompanied with more profound changes suppression of vasodilatory effects of LP is greater than in transient experimental hypercholesterolemia. Consequently, changes of lipid and apo composition of LP and weakening of their vasodilatory action play a considerable role in the vessel tone changes in atherogenic situation.
