Maintenance of cerebral blood flow and metabolism during pharmacological hypotension in aged hypertensive rats.
Cerebral blood flow (CBF) and cerebral oxygen metabolism (CMRO2) were measured in aged (24 month) spontaneously hypertensive rats (SHR) during sodium nitroprusside (SNP) and nitroglycerin induced hypotension. Both CBF and CMRO2 were decreased in SHR during hypotension induced with SNP. Significant decrements in CMRO2 were observed in aged SHR during even moderate hypotension (80-90 torr). Cerebral autoregulatory responses during nitroglycerin infusion in aged SHR were similar to SNP treated WKY and CMRO2 was maintained at control levels under all hypotensive test conditions. These results indicate that aged SHR are susceptible to cerebral ischemia during SNP induced hypotension, probably due to the combined effects of aging and hypertension on the cerebral vasculature. NTG moderated the decreases in CBF and CMRO2 seen during hypotensive challenges and may decrease the risk of stroke during hypotensive anesthesia.
D000818:Animals; D001794:Blood Pressure; D001921:Brain / Q000378:metabolism*; D002560:Cerebrovascular Circulation; D006973:Hypertension / Q000235:genetics / Q000503:physiopathology*; D007022:Hypotension / Q000139:chemically induced / Q000503:physiopathology*; D005996:Nitroglycerin; D009599:Nitroprusside; D010101:Oxygen Consumption; D051381:Rats; D011922:Rats, Mutant Strains
D009599:Nitroprusside; D005996:Nitroglycerin