Inhibitory effects of neuropeptide Y (NPY) on CRF and stress-induced cecal motor response in rats.
The effects of NPY on CRF and stress-stimulated cecal motility were investigated by electromyography in rats. Intracerebroventricular (ICV) injection of NPY at 300 ng/kg significantly reduced the frequency of spike burst during the first 15 minutes after its administration while no effect was observed at a lower dose (150 ng/kg). Exposure to mental stress (MS) increased significantly (p less than 0.01) during 45 minutes, the frequency of cecal spike bursts. NPY (300 ng/kg) injected ICV, 30 minutes prior to MS periods abolished the excitatory effect induced by stress. The frequency of cecal spike bursts was also increased during the first 15-minutes following ICV injection of CRF (300 ng/kg). Prior (5 min) ICV administration of NPY (150 ng/kg) abolished the stimulatory effect of CRF on cecal motility. It is concluded that central administration of NPY suppresses the stress-induced cecal motor response probably by inhibiting the pathways involved in CRF mediation of these effects.
Jiménez
M
M
Department of Pharmacology, INRA, Toulouse, France.
Buéno
L
L
D000818:Animals; D001921:Brain / Q000187:drug effects*; D002432:Cecum / Q000187:drug effects / Q000502:physiology*; D003346:Corticotropin-Releasing Hormone / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005769:Gastrointestinal Motility / Q000187:drug effects*; D008297:Male; D009043:Motor Activity / Q000187:drug effects*; D009478:Neuropeptide Y / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D013312:Stress, Physiological
D009478:Neuropeptide Y; D003346:Corticotropin-Releasing Hormone