Persistent hypertension does not alter the cerebral blood flow and glucose utilization in young-adult Dahl salt-sensitive rats

Abstract

The Dahl–Iwai salt-sensitive (DS) rat develops hypertension due to a high-salt diet without any structural alterations of the brain arteries and arterioles. We investigated the effect of persistent hypertension on the regional cerebral blood flow (rCBF) and regional cerebral glucose utilization (rCGU) in the DS rats. The rats were fed either a high-salt diet (HSD; 8% NaCl, n=5) or a low-salt diet (LSD; 0.3% NaCl, n=6) from 8 to 16 weeks of age, and the HSD group developed hypertension lasting for 1 month. At 16 weeks of age, the rCBF was measured in the sensorimotor and visual cortices using the hydrogen clearance method, and the rCGU was measured in 26 different brain structures using the [ 14C]deoxyglucose method. The mean arterial pressure was significantly higher in the HSD group (168±7 mm Hg) than in the LSD group (139±3 mm Hg) ( P<0.01). The mean rCBF and the rCGU values tended to be lower in the HSD group than in the LSD group; however, there were no statistically significant differences except for the reduced rCGU value in the nucleus accumbens. These results suggest that hypertension itself does not alter either the rCBF or the rCGU in young-adult DS rats. This indicates that the functional/structural changes of the cerebral arteries and arterioles that are associated with hypertension appear to be responsible for altered rCBF and rCGU in other animal models of hypertension.