Central and peripheral catecholamine stores in spontaneously hypertensive rats under immobilization stress

Abstract

The effects of increasing duration of immobilization stress (from 30 min to 240 min) on catecholamine stores in some central (hypothalamus, corpus striatum) and peripheral tissues (suprarenal glands, heart auricles) in spontaneously hypertensive rats were investigated. Sufficiently long immobilization induced significant depletion of both central and peripehral catecholamine stores. The greatest depletion occurred in the suprarenal gland(adrenaline) and in the hypothalamus (noradrenaline and dopamine). The corpus striatum (dopamine) and the heart auricles (noradrenaline) were the most resistant to immobilization stress. These data indicate that catecholamine depletion in all investigated structures in spontaneously hypertensive rats depended on the duration of immobilization. If was concluded that after immobilization for more than 30 min the release of catecholamines was stronger that the processes of synthesis and reuptake, thus leading to progressive depletion of catecholamine stores, particularly when imobilization lasted up to 240 min. The present results indicate a difference in the effects of immobilization stress on catecholamine stores between some brain regions and peripheral tissues in spontaneously hypertensive rats.