The aortic bodies of spontaneously hypertensive (SHR) and normotensive rats--a study concerning location and size

The aortic bodies, including the right and left subclavian bodies and the superior aorticopulmonary bodies, were examined in inbred normotensive control rats (NCR) of the Wistar strain and in spontaneously hypertensive rats (SHR) of the OKAMOTO-AOKI strain. Paraganglia were found in all rats of either group. They were located near to the left common carotid artery and less frequently between the branching right subclavian and right common carotid artery. Superior aorticopulmonary bodies were rarely seen. No significant differences were found regarding the volume of individual aortic bodies when comparing these paraganglia in NCR and SHR. However, aortic bodies are more numerous in SHR and therefore the total volume of aortic body tissue per rat is significantly larger in this strain. There was good correlation between the total volume of aortic bodies and the total volume of carotid bodies in both strains of rats studied. These findings indicate, that the paraganglionic system as a whole is enlarged in SHR. This enlargement probably is caused genetically and not a result of increased blood pressure.