B-Type and C-Type Natriuretic Peptides Modify Norepinephrine Uptake in Discrete Encephalic Nuclei of the Rat

RODRIGUEZ FERMEPIN M; VATTA MS; BIANCIOTTI LG; WOLOVICH T; FERNADEZ BE

CELLULAR AND MOLECULAR NEUROBIOLOGY.

SPRINGER/PLENUM PUBLISHERS

Lugar: New York; Año: 2000 vol. 20 p. 763 - 771

0272-4340

1. We previously demonstrated that atrial natriuretic factor and B- and C-type natriureticpeptides (ANF, BNP, and CNP, respectively) modified catecholamine metabolismby increasing the neuronal uptake and decreasing the neuronal release of norepinephrinein the rat hypothalamus. The aim of the present work was to study the effects of natriureticpeptides BNP and CNP on norepinephrine uptake as an index of the amine metabolismin discrete areas and nuclei of the central nervous system (CNS) of the rat.2. Experiments were carried out in vitro using the punchout technique in diverseareas and nuclei of rat CNS. Results showed that 100 nM BNP and 1 nM CNP incresednorepinephrine (NE) uptake in all brain areas and nuclei studied.3. Present results permit us to conclude that BNP and CNP regulate NE metabolismindependently of the encephalic area or nucleus involved. In fact, NE uptake increasedin nuclei related to the regullation of cardivascular activity as well as nuclei associatedwith endocrine metabolism and hydrosaline homeostasis. These observations suggest thatBNP and CNP may be involved in the regulation of these physiological processes in anindirect manner through modifications of noradrenergic neurotransmission. Present findingsprovide futher support to the hypothesis that CNP would be the main natriureticpeptide in brain. Furthermore, previous as well as present results support the role of thenatriureic peptides as neuromodulators of noradrenergic transmission at the presynapticlevel.