Stimulatory effect of angiotensin II on the proliferation of mouse spleen lymphocytes in vitro is mediated via both types of angiotensin II receptors.

The influence of different concentrations of angiotensin II (ANG II) and two specific nonpeptide ANG II receptor antagonists losartan (AT1 receptor blocker) and PD 123319 (AT2 receptor blocker) on the spontaneous proliferation of mouse spleen lymphocytes has been estimated in vitro by the [3H]thymidine uptake assay. It was found that ANG II (10(-6)-10(-12)M) significantly enhanced the [3H]thymidine incorporation into DNA of mouse splenocytes with the maximal effect at 10(-10)M. This stimulatory effect of ANG II on the proliferation of mouse spleen lymphocytes was completely blocked when ANG II receptor antagonists losartan (10(-8)M) or PD 123319 (10(-8)M) were added together with ANG II (10(-10)M). Losartan or PD 123319 tested alone were inactive in this experimental conditions. This findings indicate for the first time the stimulatory effect of ANG II on the proliferation of mouse spleen lymphocytes in vitro. This effect seems to be mediated by both types of ANG II receptors.