Atrial natriuretic factor does not affect norepinephrine catabolism in rat hypothalamus and adrenal medulla

VATTA MS; RUBIO M; BIANCIOTTI LG; FERNADEZ BE

NEUROSCIENCE LETTERS

ELSEVIER IRELAND LTD

Lugar: Amsterdam; Año: 1998 vol. 253 p. 151 - 154

0304-3940

We have previously reported that atrial natriuretic factor (ANF) increases neuronal uptake and endogenous content ofnorepinephrine (NE) and diminishes neuronal release, synthesis and turn-over of NE in rat hypothalamus and adrenal medulla.The aim of the present work was to study another aspect of NE metabolism and therefore investigate the possible effects of ANFon NE catabolism. The determination of monoamine oxidase (MAO) and catechol-O-methyl transferase (COMT) activity anddeaminates metabolites formation were studied in vitro in rat hypothalamus and adrenal medulla slices. Results showed that, inthe hypothalamus, 100 nM ANF diminished MAO activity while 10 nM ANF did not modify the enzyme activity. Conversely, 10and 100 nM ANF reduced MAO activity in adrenal medulla. On the other hand, the atrial factor modified neither COMT activitynor the formation of deaminates metabolites in the hypothalamus and adrenal medulla. Present results as well as previousfindings support a putative role for ANF in the modulation of NE metabolism not only in the hypothalamus but also in the adrenalmedulla of the rat, affecting the storage, release and uptake of NE but not its catabolism.