Local cerebral blood flow in gently restrained rats: effects of propranolol and diazepam

The cerebrovascular consequences of the gentle restraint commonly used for the measurement of local cerebral blood flow (LCBF) in conscious rats has been tested by using two drugs, propranolol and diazepam. Propranolol induced small LCBF decreases in 7 structures suggesting that the cerebral circulation was partially controlled by the activation of intra or extracerebral aminergic pathways in this protocol. Sedative doses of diazepam reduced LCBF in most of the structures but anxiolytic doses increased it in 4 structures. This effect may be due to a regionally differentiated modification of activity in the brain due to the selective inhibition of limbic structures by diazepam. Since propranolol and diazepam induced only small changes, the LCBF of gently restrained rats appeared to be minimally affected by the stressful situation imposed by the protocol.