Abstract
FUNYU, T., KIMURA, T., YAMAMOTO, T., OTA, K., SHOJI, M., OHTA, M., SATO, K. and ABE, K. Role of Atrial Natriuretic Peptide in Interleukin 1β-Induced Natriuresis in Conscious Rats. Tohoku J. Exp. Med., 1995, 177 (1), 73-87 - To assess whether atrial natriuretic peptide (ANP) plays a role in the natriuresis induced by interleukin 1β (IL-1β), the following experiments were carried out. Experiment (Ex) I: IL-1β (7.5μg/kg BW) was given intravenously (i.v.) in conscious hydrated rats (n=6). Plasma ANP, vasopressin (AVP) osmolality (Posm), Na and K, urine Na (UNaV) and K excretion (UKV), osmolality and flow (UF), and mean arterial blood pressure (MABP) and heart rate were simultaneously determined. In the control group (n=6), the drug was omitted, and the same protocols were carried out. Ex II: Three mg/kg BW of the specific ANP antagonist, HS-142-1 (HS), was administered i.v. and then, IL-1β (7.5μg/kg BW) was given i.v. (n=6). In the HS alone group (n=6), IL-1β was omitted. The experimental protocols were the same as those in Ex I. IL-1β increased significantly plasma ANP and AVP and UNaV, but not UF, accompanied by decreases in Posm and UKV and increases in MABP (ExI). HS inhibited the natriuresis mediated by IL-1β, despite increases in plasma ANP and had no influence on plasma AVP and MABP. In the control (ExI) and HS alone (EXII) groups, these parameters did not change, except for decreases in Posm in both groups and increased plasma ANP in the latter. These results suggest that plasma ANP may play an essential role in the IL-1β-mediated natriuresis.
