Blockade of angiotensin II AT1 receptors inhibits pressor action of centrally administered interleukin-1beta in Sprague Dawley rats.
The aim of the present study was to evaluate the influence of intraventricular administration of recombinant rat interleukin-1beta (IL-1beta) on regulation of resting blood pressure and heart rate and to test the hypothesis that the brain angiotensinergic system is involved in regulation of hemodynamic parameters by centrally applied IL-1beta. The experiments were performed on Sprague Dawley rats, assigned to three series of experiments. In series 1 (control, n = 6), mean arterial pressure (MAP) and heart rate (HR) were recorded for 15 min under baseline conditions. This was followed by infusion of saline (0.9% sterile NaCl 5 microL/h) into the left cerebral ventricle (LCV). Measurements were continued during the next 60 min. In series 2 (n = 6) and 3 (n = 6) the experimental design was similar, except that in series 2 the animals were LCV infused with saline containing IL-1beta (100 ng/h) and in series 3 with saline containing IL-1beta (100 ng/h) and angiotensin type 1 (AT1) receptors antagonist (Losartan, 10 microg/h). LCV infusion of saline alone did not influence MAP and HR while administration of IL-1beta elicited significant increase in MAP, but not in HR. The pressor effect was absent during combined infusion of IL-1beta and Losartan. Results of the study provide evidence that centrally administered IL-1beta exerts pressor effect, and reveal that this effect is mediated by stimulation of the brain angiotensin system and requires activation of AT1 receptors.
Ufnal
Marcin
M
Department of Experimental and Clinical Physiology, Medical University of Warsaw, Poland. marcinufnal@poczta.onet.pl
Zera
Tymoteusz
T
Szczepańska-Sadowska
Ewa
E
D047228:Angiotensin II Type 1 Receptor Blockers / Q000008:administration & dosage / Q000378:metabolism* / Q000494:pharmacology; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D007276:Injections, Intraventricular; D007375:Interleukin-1 / Q000008:administration & dosage / Q000378:metabolism* / Q000494:pharmacology*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D044140:Receptor, Angiotensin, Type 1 / Q000378:metabolism*
D047228:Angiotensin II Type 1 Receptor Blockers; D007375:Interleukin-1; D044140:Receptor, Angiotensin, Type 1