Possible Interaction: Neuropeptide Y and Oxytocin

“ Oxytocin treatment significantly reduced the NPY response to hypoglycemia.”

“The finding demonstrates for the first time in humans that the systemic administration of OT exerts an inhibitory effect on the NPY rise caused by insulin-induced hypoglycemia.”

“The intra-arterial infusions of NPY also increased (P< or =0.05) in a dose-dependent manner the secretion rate of oxytocin , which was positively correlated (P< or =0.05) with the observed increase in ovarian blood flow.”

“ NPY significantly increased ACTH, corticosterone and oxytocin secretion in the virgins but had no such effect on ACTH or oxytocin in the pregnant rats; the corticosterone response to NPY was markedly attenuated in pregnant rats.”

“Furthermore, the addition of NPY to oxytocin during the perifusion elicited a further increase in LH release (p < 0.05).”

“Stimulation of LH release by GnRH was synergistically augmented by exposure of the tissue to … (p < 0.01) or NPY (p < 0.05) for the immediately preceding 2 h. When NPY was … oxytocin in the perifusion medium, stimulation of LH release … GnRH was increased even further (p < 0.05).”

“However, long-term infusions of NPY for 5 days increased to response to both NPY and OT.”

“Short-term exposures to NPY markedly desensitized the tissue affecting subsequent responses to NPY as well as to oxytocin (OT).”

“Injection of NPY or of the related peptide YY (PYY) alone into the SON or the PVN/ACN also dose dependently increased plasma OT ; this was also significantly attenuated by prazosin.”

“The cooperative stimulation by NE and NPY may be of physiological importance in mediating the episodic release of OT in response to suckling.”

“These results indicate that 1) the stimulatory noradrenergic influence on OT secretion in the lactating rat is mediated by the alpha-1 adrenergic receptor …) NPY also stimulates OT secretion in the lactating rat through the Y-1 receptor subtype in the PVN/ACN and SON; 3) NPY … OT secretory ….”