[Endothelial hyperactivation in heat shock in rats of different genetic strains].

Heat shock was found to induce a drop in the AP due to the endothelium-dependent relaxation of the vessels and potentiation of the endothelium suppression of the vasoconstrictor responses. The responses were more obvious in the August rats as compared with the Wistar line. No lines or rats revealed any changes in the sensitivity of adrenoceptors to the agonist which suggests a leading role of the nitrogen oxide hyperproduction in these effects of the heat shock. The data obtained show that inherent endothelial-dependent vascular responses to heat shock may play a role in resistance against the shock in rats of different genetic lines.