A comparison of the blood supply of the carotid body in rats and rabbits.

Light-microscopic findings regarding the arterial blood supply of the carotid bodies in 145 Wistar rats, in 175 spontaneously hypertensive rats (SHR) and in 14 rabbits were compared. In rats, only one glomic artery was found in each of 637 carotid bifurcations. In 2 bifurcations 2 carotid body arteries supplied the glomus caroticum, the glomic artery being of the muscular type. At the origin of the carotid body artery almost regularly intraarterial cushions were observed in rats. They were also demonstrable at the origin of first or second order branches of the glomic artery. Concerning the origin of the carotid body artery as well as presence and form of the intraarterial cushions some differences between the 2 strains of rats studied were detected. In rabbits the glomic artery was of the elastic type. In 2 out of 28 carotid bifurcations 2 carotid body arteries were found. In all other cases the glomus caroticum was supplied by one artery only. The glomic artery did not terminate in the glomus caroticum in rats as well as in rabbits. Many similarities between the light-microscopic picture of the internal carotid artery and the carotid body artery were observed in rabbits. Therefore a baroreceptor function of the glomic artery seems to be possible.