Central natriuretic peptides regulation of peripheral atrial natriuretic factor release

Atrial natriuretic factor (ANF) and C-type natriuretic peptide (CNP) recept ors have been described in encephalic areas and nuclei related to the regul ation of cardiovascular as well as sodium and water homeostasis. Stimulatio n of the anterior ventral third ventricular region of the brain modifies pl asma ANF concentration, suggesting the participation of the central nervous system in the regulation of circulating ANF. The aim of this work was to s tudy the effect of centrally applied ANF or CNP on plasma ANF. Normal and b lood volume expanded rats (0.8 ml isotonic saline/100 g body weight) were i ntra cerebralventricularly injected with 1, 10 or 100 ng/mu l/min ANF. Bloo d volume expanded animals were also centrally injected with the same doses of CNP. Blood samples were collected at 5 and 15 min. after intracerebralve ntricular administration of either ANF or CNP. Centrally applied ANF did no t affect circulating ANF in normal blood volume rats. In blood volume expan ded animals both ANF (1, 10 or 100 ng/mu l/min) and CNP (1 ng/mu l/min) dec reased plasma ANF concentration after 15 min. Moreover, CNP(10 and 100 ng/m u l/min) lowered circulating ANF levels not only at 15 min but also at 5 mi n. Neither ANF nor CNP elicited any change in mean arterial pressure and he art rate in normal and blood volume expanded rats. These results suggest th e existence of a central regulation exerted by natriuretic peptides on circ ulating ANF levels. Furthermore, this is the first study reporting an effec t on plasma ANF induced by centrally applied CNP. (C) 2000 Elsevier Science B.V. All rights reserved.