Comparison of carotid sinus baroreceptors in dogs, cats, monkeys, and rabbits.

Single-unit recordings were obtained from the vascularly isolated Krebs-Henseleit-perfused carotid sinus of the rabbit and cat, and the results were compared with those obtained previously from the monkey and dog. Carotid sinus pressure was altered using static pressure steps. There was a highly significant correlation between resting arterial pressure and carotid sinus baroreceptor threshold pressure. The baroreceptors of the monkey and rabbit had a significantly lower threshold than those of the dog and cat. The baroreceptors of the monkey had a significantly lower gain than those of the three nonprimates. This is the first study in which baroreceptor activity has been studied under the same experimental conditions in four different species.