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-β-hydroxylase (DBH) phenylethanolamine N-methyltransferase (PNMT), β1-, β2- and β3-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 β1- and β2-adrenoceptors were recorded, whereas β3-adrenoreceptor mRNA level was significantly elevated in right atria of CMS rats. At the same time, CMS produced a significant increase of β1- and β2-adrenoreceptor mRNA levels in left atria, but did not affect β3-adrenoceptor mRNA level.The results presented here suggest that stress-induced depression expressed differential effects on catecholamine biosynthetic enzymes and β-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 response and may play a role in the pathophysiology of cardiovascular function.