Mouse Glycine N-methyltransferase is Sexually Dimorphic and Regulated by Growth Hormone

The secretion pattern of putuitary growth hormone (GH) in rodents is sexually dimorphic and regulates the expression of some hepatic genes. We report cloning of mouse glycine N-methyltransferase (GNMT) cDNA. The mouse GNMT mRNA is expressed at much lower levels in male than in female livers. Hypophysectomy in male mice resulted in as a high level of the expression as in female mice. Treatment with GH of hypophysectomized 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.