Prostaglandim E2 increases adenosine 3′,5′-monophosphate concentration and binding-site occupancy, and stimulates serotonin-N-acetyltransferase activity in rat pineal glands in vitro

The effects of prostaglandins (PGs) on rat pineal metabolism were examined in vitro. PGE2 (0.01-1 μM) increased the activity of serotonin-N-acetyltransferase (SNAT), the stimulation curve exhibiting a maximum at 0.1 μM. PGE1 increased SNAT activity only at the highest dose (1 μm) whereas PGF2α, 15-k...

Descripción completa

Guardado en:
Detalles Bibliográficos
Autores principales: Ritta, M.N., Cardinali, D.P.
Formato: JOUR
Materias:
cAMP
cAMP-binding sites
melatonin synthesis
pineal
prostaglandins
acyltransferase
arylamine acetyltransferase
cyclic AMP
prostaglandin derivative
prostaglandin E
prostaglandin E2
aralkylamine acetyltransferase
cyclic amp
drug receptor
prostacyclin
prostaglandin e2
prostaglandin f2 alpha
radioisotope
animal
article
binding site
comparative study
drug effect
enzyme activation
in vitro study
male
metabolism
pineal body
rat
rat strain
15 oxoprostaglandin f2 alpha
acetyl coenzyme a c 14
animal experiment
cyclic amp h 3
dose response
drug response
endocrine system
Acetyltransferases
Animal
Arylamine N-Acetyltransferase
Binding Sites
Comparative Study
Cyclic AMP
Dinoprostone
Enzyme Activation
In Vitro
Male
Pineal Gland
Prostaglandins E
Prostaglandins, Synthetic
Rats
Rats, Inbred Strains
Support, Non-U.S. Gov't
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_03037207_v23_n2_p151_Ritta
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
Descripción
Sumario:The effects of prostaglandins (PGs) on rat pineal metabolism were examined in vitro. PGE2 (0.01-1 μM) increased the activity of serotonin-N-acetyltransferase (SNAT), the stimulation curve exhibiting a maximum at 0.1 μM. PGE1 increased SNAT activity only at the highest dose (1 μm) whereas PGF2α, 15-keto-PGF2α or PGI2 did not affect the enzymic activity. The stimulation of SNAT activity brought about by PGE2 in pineals from ganglionectomized rats was greater than in sham-operated controls at all the doses studied, suggesting that the observed effect is predominantly post-synaptic. Only PGE2 significantly increased pineal cAMP accumulation in vitro at doses between 0.01 and 1 μm, and depressed the unoccupied cAMP-binding sites in pineal 900 g supernatants. The total number of cAMP-binding sites remained unaltered after incubation of PGE2. The present observations together with the previously reported NE-induced release of PGs in incubated pineal glands, the occurrence of pineal PG-binding sites and the indomethacin blockade of the nocturnal rise of pineal SNAT and melatonin content, support a role for PGs in the control of melatonin synthesis. © 1981.

Ejemplares similares