Dendroaspis natriuretic peptide administered intracerebroventricularly increases renal water excretion

1. The effects of intracerebroventricular (i.c.v.) infusion of Dendroaspis natriuretic peptide (DNP) on renal function were examined in anaesthetized rats. The results were compared with those obtained following intravenous (i.v.) infusion of the same dose of DNP. 2. Urine volume was increased four- to six-fold over basal values by i.c.v. infusion of DNP (6 pmol/min). Urine osmolality was decreased, whereas sodium excretion was not significantly altered. Intravenous infusion of the same dose of DNP had little effect on urinary water excretion. Neither arterial pressure nor heart rate was changed significantly by either i.v. or i.c.v. infusion of DNP. Glomerular filtration rate, measured by creatinine clearance, remained unaltered. 3. The diuretic response to i.c.v. DNP was markedly attenuated in rats that were deprived of their water supply for 3 days before the experiment. 4. These results suggest that DNP can act within the central nervous system to increase renal water excretion.