Evidence against the central nervous system being involved in altered reflex control of sympathetic nerve activity by atrial natriuretic peptide

This study aimed to examine whether atrial natriuretic peptide (ANP) alters arterial baroreceptor control of sympathetic nerve activity (SNA) by acting on the CNS. In rabbits anestheitized with α-chloralose, we examined changes in arterial pressuire and renal SNA in response to graded electrical stimulation (1.7, 3.3, 5.0 Hz) of aortic depressor nerves during the i.v. infusion of saline or α-human atrial natriuretic peptide (α-hANP) (0.1, 1.0 μg/kg/min) or after the i.c.v. injections of saline or α-hANP (3, 10 μg). Sinoaortic denervation and bilateral vagotomy were done before examination in all rabbits to eliminate the influence of the known effects of ANP on arterial and cardiac receptors. I.v. α-hANP decreased arterial pressure but did not alter renal SNA. I.c.v. α-hANP did not change arterial pressure or renal SNA. Arterial pressure and renal nerve responses to graded electrical stimulation of aortic depressor nerves were not altered by i.v. or i.c.v. α-hANP. These results suggest that α-hANP does not modulate control of renal SNA by acting on the CNS.