Effects of interleukin-1 beta on blood pressure, thermoregulation, and the release of vasopressin, ACTH and atrial natriuretic hormone.

To assess how interleukins (IL) affect the release of vasopressin (AVP), atrial natriuretic hormone (ANH), and ACTH and the regulation of blood pressure (BP), heart rate (HR) and rectal temperature (RT), the 3 doses of 1.73 (low dose, LD), 8.63 (medium dose, MD), and 43.16 pmol/100 gBW (high dose, HD) of human recombinant IL-1 beta were intravenously (iv) administered in conscious rats, and plasma AVP, ANH, and ACTH, BP, HR and RT were determined simultaneously. In the control group (CON), the drug was omitted. Circulatory IL-1 beta levels were determined in each dose, and indomethacin (1 mg/rat, IM) was administered iv in the HD and CON groups. Plasma IL-1 beta increased transiently following IL-1 beta administration in each group. Plasma AVP, ANH, and ACTH increased in the LD, MD, and HD groups, respectively. Mean arterial BP (MABP) and RT increased in the LD group, but HR did not change. In the MD and HD groups, MABP decreased at 30 min followed by its increase at 120 min, but RT in both groups decreased. In the CON group, these parameters did not change. IM attenuated plasma AVP and ACTH responses to HD and also inhibited decreases in MABP and RT. These results suggest that IL-1 beta affects the release of AVP and ACTH, blood pressure and thermogenesis via prostaglandins (PGs), but ANH release related to IL-1 beta may not be mediated by PGs.