Hypothalamic paraventricular nucleus mediates sodium-induced changes in cardiovascular and renal function in conscious sheep

Abstract

The contribution of the paraventricular nucleus of the hypothalamus (PVN) in mediating cardiovascular, renal, hormonal, and sympathetic nerve responses to increased cerebrospinal fluid (CSF) [Na+] was investigated in conscious sheep. Intracerebroventricular hypertonic NaCl (0.5 mol/l, 20 μl/min for 60 min) increased arterial blood pressure [AP; +13.4 (SD 2.0) mmHg, P < 0.001] and central venous pressure [CVP; +2.8 (SD 1.3) mmHg, P < 0.001], but did not significantly change heart rate or cardiac output (n = 6). Elevated CSF [Na+] also lowered plasma ANG II levels [-3.3 (SD 1.6) pmol/l, P = 0.004] and increased creatinine clearance [+31.5 (SD 32.7) ml/min, P = 0.03] and renal sodium excretion ..