Is there a serotonin-induced hypertensive coronary chemoreflex in the nonhuman primate?
The purpose of this study was to investigate the nature of the serotonin-induced coronary chemoreflex in the conscious monkey. Ten chronically prepared and four acute monkeys were used in this study. Five chronically prepared animals had catheters in the left atrium, ascending aorta, descending aorta, and, bilaterally, in the common carotid arteries. In addition, Silastic catheters were placed next to both vagi to permit vagal block with 2% lidocaine. Serotonin was injected (12-200 micrograms/kg) into the left atrium, ascending aorta, descending aorta, or, bilaterally, into the carotid arteries while blood pressure, heart rate, and respiratory movements were recorded. Injections of serotonin were associated with hypertension and bradycardia followed by tachycardia, all of which were preceded by a cough response. Atropine blocked the bradycardia, whereas atropine and phentolamine eliminated the cardiovascular components of the reflex. Vagal blockade eliminated the bradycardia but otherw
