Effects of atrial natriuretic factor on norepinephrine release in the rat hypothalamus

VATTA MS; PAPOUCHADO ML; LOCATELLI AS; BIANCIOTTI LG; FERNADEZ BE

REGULATORY PEPTIDES

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 1992 vol. 41 p. 171 - 181

0167-0115

The effects of atrial natriuretic factor on the mechanisms involved in norepinephrine release were studied 'in vitro' in slices of Wistar rat hypothalamus. Atrial natriuretic factor (10, 50 and 100 nM) decreased spontaneous [3H]norepinephrine secretion in a concentration dependent way. In addition, the peptide (10 nM) also reduced acetylcholine induced output of norepinephrine. The atrial factor (10 nM) was unable to alter the amine secretion when the incubation medium was deprived of calcium or when a calcium channel blocker such as diltiazem (100/~M) was added. In conclusion, atrial natriuretic factor reduced both spontaneous and acetylcholine evoked [3H]norepinephrine release in the rat hypothalamus. These findings suggest that the atrial natriuretic factor may alter catecholamine secretion by modifying the calcium available for the exocytotic process of catecholamine output.