B and C types natriuretic peptides modulate norepinephrine uptake and release in the rat hypothalamus

VATTA MS; PRESAS M; BIANCIOTTI LG; ZARRABEITIA V; FERNADEZ BE

REGULATORY PEPTIDES

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 1996 vol. 65 p. 175 - 184

0167-0115

We previously reported that atrial natriuretic factor (ANF) regulates catecholamine metabolism in the central nervous system. ANF, Band C types natriuretic peptides (BNP and CNP) also play a regulatory role in body fluid homeostasis, cardiovascular activity andhormonal and neuro-hormonal secretions. The aim of the present work was to investigate BNP and CNP effects on the uptake and releaseof norepinephrine (NE) in rat hypothalamic slices incubated in vitro. Results showed that BNP (100 riM) and CNP (1, 10 and 100 nM)enhanced total and neuronal [3H]NE uptake but did not modify non-neuronal uptake. BNP (100 nM) and CNP (1 nM) caused a rapidincrease in NE uptake (1 rain), which was sustained for 60 min. BNP (100 nM) did not modify the intracellular distribution of NE;however, 1 nM CNP increased the granular store and decreased the cytosolic pool of NE. BNP (100 nM) and CNP (1, 10 and 100 riM),diminished spontaneous NE release. In addition, BNP (1, 10, 100 nM) and CNP (1, 10 and 100 pM, as well as 1, 10 and 100 nM) reducedNE output induced by 25 mM KC1. These results suggest that BNP and CNP may be involved in the regulation of several central as wellas peripheral physiological functions through the modulation of noradrenergic neurotransmission at the presynaptic neuronal level. Presentresults provide evidence to consider CNP as the brain natriuretic peptide since physiological concentrations of this peptide (pM)diminished NE evoked release.