Effects of acute 1,1,1-trichloroethane inhalation on aortic nerve impulse and blood pressure.

Effects of 1,1,1-trichloroethane (1,1,1-TCE) inhalation on the afferent impulse of the aortic nerve and aortic blood pressure were investigated in anesthetized dogs. In acute inhalation experiment, the threshold concentration of 1,1,1-TCE required to produce a decrease in the aortic nerve activity was approximately 0.4% in inspired air. Moreover, this threshold level and the threshold concentration required to produce a decrease in aortic blood pressure were identical in value. The aortic nerve activity obviously decreased and at the same time was accompanied by a marked decrease in aortic blood pressure following inhalation of high 1,1,1-TCE concentration. These results suggest that the afferent pathway of aortic baroreflex may be operated at a concentration of more than 0.4% in inspired air. It is further suggested that baroreceptor reflex plays a major role in the control of arterial blood pressure following acute 1,1,1-TCE inhalation in anesthetized dogs.