Angiotensin II receptor 1 involved in the central pressor response induced by interleukin-1 beta in the paraventricular nucleus

Objective: To investigate the possible participation of angiotensin II receptor 1 (AT(1) receptor) in pressor response induced by IL-1 beta in the paraventricular nucleus (PVN) of hypothalamus. Methods: The experiments were performed on adult Wistar rats. Mean arterial pressure (MAP) were recorded during microinjection of different doses of IL-1 beta, IL-1 beta together with Losartan, an AT1 receptor antagonist, or Ang II pre-treated with IL-1 beta into PVN. Rats microinjected with saline were served as controls in all experiments. Results: Microinjection of IL-1 beta (0.1 or 0.2 ng) resulted in increases in blood pressure in a dose-dependent manner, and the pressor effect caused by administration of IL-1 beta (0.2 ng) could be attenuated by pre-treatment with AT(1) receptor antagonist (100 ng Losartan). A subpressor dose of IL-1 beta (0.05 ng) could augment the pressor response induced by microinjection of Ang II (10 ng). Discussion: The present results provide support that central infusion of IL-1 beta increases blood pressure and the pressor response requires stimulation of AT(1) receptors. It is also shown that IL-1 beta has the effect of increasing the magnitude of pressor response induced by Ang II in PVN. [Neurol Res 2009; 31: 420-424]