Is phenylethanolamine-N-methyltransferase (PNMT) contained in rat hypothalamic neurons?

Three polyclonal antisera raised against bovine adrenal phenylethanolamine-N-methyltransferase (PNMT) were used to stain PNMT-containing neurons in rat medulla oblongata and hypothalamus. Without colchicine pretreatment all three antisera stained nerve fibres in both the medulla and hypothalamus and nerve cell bodies in the medulla only. In colchicine pretreated rats one antiserum only stained cell bodies in the hypothalamus as well. All staining was prevented by prior absorption of the antiserum with purified bovine PNMT. Thus, if PNMT is present in the rat hypothalamic neurons then it is not identical to the form of PNMT present in rat medullary neurons.