Vasopressin and oxytocin gene expression in the porcine forebrain under basal conditions and following acute stress.

This study, the first using the pig, examined expression of mRNAs for vasopressin (VP), oxytocin (OT), preproenkephalin (PENK) and pro-opiomelanocortin (POMC) in the forebrain, and of POMC and prolactin in the pituitary. High basal expression of VP and OT mRNAs was present in the paraventricular (PVN) and supraoptic (SON) nuclei. In the PVN, VP was found in magnocellular regions whereas OT was also seen in the parvocellular portion; the distribution of VP and OT mRNAs in the SON was as reported in other species. The suprachiasmatic nucleus contained VP mRNA but only OT message was present in the dorsomedial SON, a structure peculiar to swine. Gene expression for PENK occurred in the caudate putamen (CPu), for POMC in the mediobasal hypothalamus (MBH) and for prolactin and POMC in the hypophysis. Following restraint, VP message increased in the magnocellular PVN, as did PENK in the CPu and POMC in the MBH.