Reduction of regional cerebral blood flow by melatonin in young rats

Abstract

Melatonin (10 ng) was subcutaneously administered to 14-day-old Sprague-Dawley rats. Regional blood flow (rCBF) was measured in 22 anatomically defined structures 20 min later using iodo[14C]antipyrine and quantitative autoradiography. rCBF was markedly reduced in the cerebral areas supplied by circle of Willis and the basilar arteries. Melatonin also significantly decreased blood flow to choroid plexuses. These findings suggest that circulating melatonin may contribute to regulation of cerebral blood flow and brain fluid balance.