MOUSE GLYCINE N-METHYLTRANSFERASE IS SEXUALLY DIMORPHIC AND REGULATEDBY GROWTH-HORMONE

The secretion pattern of putuitary growth hormone (GH) in rodents is s exually dimorphic and regulates the expression of some hepatic genes. We report cloning of mouse glycine N-methyltransferase (GNMT) cDNA. Th e mouse GNMT mRNA is expressed at much lower levels in male than in fe male livers. Hypophysectomy in male mice resulted in as a high level o f the expression as in female mice. Treatment with GH of hypophysectom ized male mice twice a day for 5 days decreased the expression. These results indicate that the sex difference of the mouse GNMT expression is regulated by GH secretion patterns.