[Peripheral vasodilator effect of 1,1,1-trichloroethane inhalation].

It is presumed that systemic hypotension resulting from high concentration of 1,1,1-trichloroethane (1,1,1-TCE) inhalation may be induced by functional depression of the central nervous system. However, it is still uncertain the possibilities that one of the site of action where 1,1,1-TCE acts in systemic hypotension existed in the portion without the central nervous system. The present experiment was performed to investigate the role of the peripheral vessels as a site of action in the systemic hypotension following 1,1,1-TCE inhalation. The right hindlimb of a dog anesthetized with sodium pentobarbital (25-30 mg/kg, intravenously) was amputated at the central level of the thigh bone leaving muscles and nerves. The isolated hindlimb was perfused with blood at a constant flow rate using a pump. Venous blood circulated in the isolated hindlimb was returned to the femoral vein. To measure the perfusion pressure of the isolated hindlimb, a small catheter was inserted into the artery and was connected to a pressure transducer (Nihon Kohden, MPU-0.5). In this perfusion experiment, the changes in perfusion pressure following 1,1,1-TCE inhalation are shown to be the reaction of peripheral vessels only as the site of action of 1,1,1-TCE. In other words, the effects of 1,1,1-TCE on central nervous system could be completely removed. Various concentrations of 1,1,1-TCE vapor, made by an inside circuit vaporizer, were inhaled during a period of approximately 2 min. Perfusion pressure was continuously recorded before, during and after the termination of inhalation.(ABSTRACT TRUNCATED AT 250 WORDS)