MANY PEPTIDES THAT ARE PRESENT IN THE EXTERNAL ZONE OF THE MEDIAN-EMINENCE ARE NOT SECRETED INTO THE HYPOPHYSEAL PORTAL BLOOD OF SHEEP

Abstract

Apart from the well recognized factors that are produced by the hypothalamus and secreted into hypophysial portal blood to regulate pituitary function, there is a range of neuropeptides that are present in the median eminence and could be secreted to serve a modulatory function. In this study we have collected hypophysial portal blood and jugular venous blood from sheep in an attempt to identify which of these putative modulatory peptides might be secreted from the median eminence. We have measured neuropeptide Y (NPY), substance P (SP), galanin (GAL), neurokinin A (NKA), peptide histidine isoleucine (PHI), vasoactive intestinal peptide (VIP), neurotensin (NT) and cholecystokinin (CCK). We a..