In vitro effect of neuropeptide Y on melatonin and norepinephrine release in rat pineal gland.
1. To study neuropeptide Y (NPY) effect on melatonin production, rat pineal explants were incubated for 6 hr with 10-1,000 nM NPY in the presence or absence of 10 microM norepinephrine (NE). Melatonin content in the pineal gland and media was measured by radioimmunoassay (RIA). 2. NPY (10-1,000 nM) increased melatonin production and, at 10 or 100 nM concentrations (but not 1,000 nM), enhanced NE stimulation of melatonin production. 3. NPY (1,000 nM) impaired 3H-labeled transmitter release induced by a K+ depolarizing stimulus in rat pineals incubated with 3H-NE. 4. These results suggest that NPY affects both pre- and postsynaptic pineal mechanisms.
Vacas
M I
MI
Departamento de Fisiología, Facultad de Medicina, UBA, Buenos Aires, Argentina.
Sarmiento
M I
MI
Pereyra
E N
EN
Etchegoyen
G S
GS
Cardinali
D P
DP
D000818:Animals; D066298:In Vitro Techniques; D008297:Male; D008550:Melatonin / Q000096:biosynthesis / Q000378:metabolism*; D009478:Neuropeptide Y / Q000494:pharmacology*; D009638:Norepinephrine / Q000378:metabolism* / Q000494:pharmacology; D010870:Pineal Gland / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains
D009478:Neuropeptide Y; D008550:Melatonin; D009638:Norepinephrine