Regulation of atrial catecholamine enzymes and adrenoceptor gene expression after chronic stress

Chronic stress is a risk factor for the development of numerous psychopathological conditions in humans including depression. Changes in gene expression of tyrosine-hydroxylase (TH), dopamine-beta-hydroxylase (DBH) phenylethanolamine N-methyltransferase (PNMT), beta(1)-, beta(2)-and beta(3)-adrenoceptors in right and left rat atria upon chronic unpredictable mild stress (CMS) were investigated. CMS decreased TH and DBH gene expression levels both in right and left atria and increased PNMT mRNA in left atria. No changes in mRNA levels of beta(1)-and beta(2) adrenoceptors were recorded, whereas beta(3)-adrenoreceptor mRNA level was significantly elevated in right atria of CMS rats. At the same time, CMS produced a significant increase of beta(1)-and beta(2)-adrenoreceptor mRNA levels in left atria, but did not affect beta(3)-adrenoceptor mRNA level. The results presented here suggest that stress-induced depression expressed differential effects on catecholamine biosynthetic enzymes and beta-adrenoceptors at molecular level in right and left atria of adult rat males. Elevated gene expression of PNMT in left atria of rats exposed to CMS can lead to altered physiological esponse and may play a role in the pathophysiology of cardiovascular function