Modulation of the rat adrenal medulla norepinephrine secretion in a sodium-free medium by atrial natriuretic factor.
The effects of atrial natriuretic factor (ANF) on [3H]norepinephrine ([3H]NE) release evoked by a sodium-free medium (SFM) were studied. Experiments were performed in rat adrenal medulla slices incubated in vitro. Results showed that [3H]NE release evoked by the omission of Na+ was decreased by 10 nM ANF. In addition, when the Ca2+ was omitted from the SFM, NE output was partially diminished. Nevertheless, if ANF was added to SFM/Ca(2+)-free medium (CFM), NE secretion showed no modifications compared with SFM/CFM. Present results raise the hypothesis that two mechanisms could be involved in NE output evoked by a SFM in the rat adrenal medulla: one independent of and the other dependent on the extracellular calcium. Moreover, ANF only diminished NE secretion evoked by SFM dependent on extracellular calcium and did not modify calcium-independent NE release.
Vatta
M S
MS
Cátedras de Fisiología & Fisiopatología, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Argentina.
Papouchado
M L
ML
Bianciotti
L G
LG
Fernandez
B E
BE
D000313:Adrenal Medulla / Q000187:drug effects* / Q000378:metabolism; D000818:Animals; D009320:Atrial Natriuretic Factor / Q000494:pharmacology*; D002118:Calcium / Q000494:pharmacology; D003470:Culture Media; D005089:Exocytosis / Q000187:drug effects*; D066298:In Vitro Techniques; D008297:Male; D009638:Norepinephrine / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D012964:Sodium / Q000502:physiology; D013268:Stimulation, Chemical
D003470:Culture Media; C472610:atrial natriuretic peptide, rat; D009320:Atrial Natriuretic Factor; D012964:Sodium; D002118:Calcium; D009638:Norepinephrine