EFFECT OF SYMPATHOMIMETIC DRUGS AND CORRESPONDING RECEPTOR ANTAGONISTS ON THE RATE OF CEREBROSPINAL-FLUID PRODUCTION

The bulk production of cerebrospinal fluid (CSF) was measured in rabbits on the basis of ventriculocisternal perfusion and dilution of [14C]inulin. Intraventricular or intravenous (i.v.) infusion of norepinephrine produced a dose-related decrease in the production by as much as 50%, the effect being counteracted by both α- and β-antagonists (except when the latter was given i.v., which potentiated the i.v. norepinephrine response). Also intraventricular (but not i.v.) administration of the β1-receptor agonist, H80 62, reduced CSF formation (effect blocked by practolol), in contrast to the β2 agonist, terbutaline, which had little or no effect. It is suggested that the sympathomimetic reduction in the rate of CSF formation is the result of a combined β1-receptor-mediated inhibition of the secretion from the plexus epithelium and a reduced blood flow in the tissue resulting from stimulation of the vascular α-receptors. © 1979.