The Regulation of Catecholamine Biosynthesis by the Gas Transmitters Carbon Monoxide and Hydrogen Sulfide.

The gas transmitters nitric oxide (NO), carbon monoxide (CO), and hydrogen sulfide (H2S) play important roles in physiological regulation, including adrenal function. Among them, only NO has been directly implicated in controlling catecholamine biosynthesis. This study examined whether CO and H2S exert similar effects by treating PC12 cells with a CO donor (CORM-2) or an H2S donor (NaHS), with or without glucocorticoid stimulation. Gene expression of tyrosine hydroxylase (Th), dopamine β-hydroxylase (Dbh), and phenylethanolamine N-methyltransferase (Pnmt) was assessed by RT-qPCR, and catecholamine release was measured by ELISA. We found that exogenous CO decreased Th and Dbh expression, attenuated glucocorticoid-induced upregulation of catecholamine biosynthesis genes, and differentially modulated dopamine and norepinephrine release. In contrast, exogenous H2S treatment had no significant effect. These findings identify CO as a novel regulator of catecholamine biosynthesis and highlight important differences among gas transmitters in stress-related signaling.