Effects of Immobilization Stress on Cerebral Blood Flow and Cerebrovascular Permeability in Spontaneously Hypertensive Rats

Abstract

Immobilization of unanesthetized, freely breathing, 10–12-month-old, spontaneously hypertensive rats (SHR) did not significantly alter regional cerebral blood flow (rCBF) in 13 of 14 brain regions assayed. After 5 or 15 min of immobilization, rCBF was unchanged except at the frontal lobe, where it rose significantly by 21%. Furthermore, immobilization did not increase the cerebrovascular permeability–area product for 14C-sucrose, except at three brain regions. The results indicate that immobilization of SHR does not significantly affect rCBF or blood–brain barrier permeability in most regions of the brain, and suggest that adequate autoregulation of rCBF is maintained under stress.