Cytosolic calcium changes induced by angiotensin II in human peripheral blood mononuclear cells are mediated via angiotensin II subtype 1 receptors
P Lijnen, R Fagard, V Petrov - Journal of hypertension, 1997 - journals.lww.com
P Lijnen, R Fagard, V Petrov
Journal of hypertension, 1997•journals.lww.comObjective To determine the effects of angiotensin II (AII)(1–8) on cytosolic free calcium
concentrations in the absence and in the presence of the selective angiotensin subtype 1
(AT 1) receptor antagonist losartan and of the selective angiotensin subtype 2-receptor
antagonist P-186 in human peripheral blood mononuclear cells (PBMC). We also assessed
the effect of the AII analogues AII (2–8), AII (3–8) and AII (4–8) on the cytosolic free-calcium
concentration in human PBMC. Methods The cytosolic free-calcium concentration was …
concentrations in the absence and in the presence of the selective angiotensin subtype 1
(AT 1) receptor antagonist losartan and of the selective angiotensin subtype 2-receptor
antagonist P-186 in human peripheral blood mononuclear cells (PBMC). We also assessed
the effect of the AII analogues AII (2–8), AII (3–8) and AII (4–8) on the cytosolic free-calcium
concentration in human PBMC. Methods The cytosolic free-calcium concentration was …
Abstract
Objective
To determine the effects of angiotensin II (AII)(1–8) on cytosolic free calcium concentrations in the absence and in the presence of the selective angiotensin subtype 1 (AT 1) receptor antagonist losartan and of the selective angiotensin subtype 2-receptor antagonist P-186 in human peripheral blood mononuclear cells (PBMC). We also assessed the effect of the AII analogues AII (2–8), AII (3–8) and AII (4–8) on the cytosolic free-calcium concentration in human PBMC.
Methods
The cytosolic free-calcium concentration was assayed in human peripheral blood mononuclear cells by measuring the fluorescence of fura-2 entrapped by these cells.
Results
Administration of AII caused a concentration-dependent increase in the cytosolic free-calcium concentration in human peripheral blood mononuclear cells with a half-maximal increase at 5× 10− 8 mol/l. Also administration of the heptapeptide AII (2–8) increased the intracellular free-calcium concentration in human PBMC, whereas AII (3–8) and AII (4–8) had no effect. The AII (1–8)-induced rise in cytosolic free-calcium concentration was blocked completely by losartan but not by P-186.
Conclusion
Our data demonstrate that the effects of AII on the cytosolic free-calcium concentration in human PBMC are AT 1 receptor-mediated since they were abolished by the specific AII AT 1 receptor antagonist losartan but not by the specific angiotensin subtype 2 receptor antagonist P-186.
Lippincott Williams & Wilkins