Effects of restraint stress on alpha(1) adrenoceptor mRNA expression in the hypothalamus and midbrain of the rat

We examined the effects of restraint stress on alpha(1) adrenoceptor mRNA e xpression in the rat brain using reverse transcriptase-polymerase chain rea ction (RT-PCR). After rats had been restrained for 10, 30, 60, 120 or 240 m in, the hypothalamus and midbrain were removed immediately and alpha(1) adr enoceptor mRNA levels in these regions were determined by RT-PCR. Blood sam ples were also collected for simultaneous measurement of serum adrenocortic otropic hormone (ACTH) and corticosterone. Restraint stress resulted in a v ariety of changes in the hypothalamus and midbrain. In the hypothalamus, 30 and 60 min of stress resulted in a significant fall in the level of alpha( 1) adrenoceptor mRNA relative to the control. This was associated with a ri se in serum ACTH and corticosterone. In the midbrain, significant elevation of alpha(1) adrenoceptor mRNA was noted after CO, 120 and 240 min of restr aint stress. Our findings indicated that the influence of restraint stress on alpha(1) adrenoceptor mRNA level in the hypothalamus is different to tha t of the midbrain region in rats. (C) 1999 Elsevier Science B.V. All rights reserved.