Altered cerebral vessel innervation in spontaneously hypertensive and renal hypertensive rats

The ultrastructural distributions of sympathetic and non-sympathetic nerve terminals in cerebral arteries of normotensive Wistar-Kyoto rats (WKY), spontaneously hypertensive rats (SHR) and one-kidney, one clip renal hypertensive rats (RHR) were examined. When compared with WKY, the SHR cerebral arteries receive denser sympathetic nerve terminals and fewer non-sympathetic nerve terminals. On the other hand, both sympathetic and non-sympathetic nerve terminals decrease in the cerebral arteries of RHR. These results suggest that the sympathetic vasoconstriction may surpass the non-sympathetic vasodilation in some brain regions of SHR, while the functional significance of cerebral sympathetic vasoconstrictor and non-sympathetic vasodilator nerves may decrease in RHR. The pattern of cerebral vessel innervation differs in different types of hypertension.