Effects of Long-term Antihypertensive Treatment on Cerebral, Thalamic and Cerebellar Blood Flow in Spontaneously Hypertensive Rats (SHR)

SUMMARY Cerebral blood flows (CBF) were measured in the parietal cortex, the thalamus and the cerebellum by the hydrogen clearance technique in anesthetized spontaneously hypertensive rats, of which hypertension was treated for 16 weeks (long-term) or 8 weeks (short-term) with antihypertensive agents of hydralazine and guanethldine. As compared to non-treated control animals, CBF in the three regions were significantly increased while the calculated cerebrovascular resistances (CVR) were decreased in hypertension-treated animals. Such CBF and CVR changes were greater in SHR with long-term than short-term therapy. Both an increase in CBF and a decrease in CVR were closely related to a fall in the blood pressure. From the present results, it was concluded that earlier and longer treatment of hypertension could lessen or even prevent the increased CVR due to the hypertensive vascular changes, and increase CBF as a result. Stroke Vol 17, No 5, 1986 CEREBRAL BLOOD FLOW (CBF) is decreased and the lower limit of CBF autoregulation is shifted to a higher level in long-lasting severe hypertension with vascular changes.1"8 Antihypertensive treatment i