[The effect of methohexital, fentanyl, droperidol, and chloralose on the aortic baroceptor discharge of decerebrated cats (author's transl)].

The effect of methohexitone, fentanyl, droperidol and chloralose on the response characteristics of aortic barorecptors was studied in decerebrated cats. The conclusions rest on the analysis of the drug effect on the stimulus-response curves of individual baroceptor fibres of the aortic region relating the average discharge rate (spike/s) to the average aortic arch pressure which was altered over wide ranges by a balloon catheter located in the thoracic aorta. The stimulus response curves were shifted to higher activities by methohexitone and less obviously also by droperidol. Contrarywise, chloralose and fentanyl shifted these curves to lower activities. Thus, the first two drugs increase the afferent receptor drive and favour the development of arterial hypotension, whereas the last two decrease the afferent receptor drive and act to stabilize the arterial pressure. Interestingly, at comparable depth of anesthesia arterial blood pressure levels tend to be lower with the first kind of anaesthetics as compared with the last.