Valsartan and PD123319 both attenuated Ang II-induced mesenteric vascular hypertrophy, suggesting that the trophic and proliferative effects of Ang II are mediated by both AT1 and AT2 receptors.
Do AT1 or AT2 receptor antagonists attenuate Angiotensin II-induced mesenteric vascular hypertrophy in male Sprague-Dawley rats?
Both AT1 and AT2 receptors mediate the trophic and proliferative effects of Angiotensin II on the mesenteric vasculature in rats.
The aim of this study was to explore the regulation of angiotensin receptors after chronic infusion with angiotensin II (Ang II) and to clarify the relative roles of the angiotensin type 1 (AT(1)) and type 2 (AT(2)) receptors in the mediation of Ang II-induced mesenteric vascular hypertrophy. In male Sprague-Dawley rats, Ang II infusion at a dose of 58.3 ng/min by subcutaneous osmotic minipumps for 14 days led to increased mesenteric weight and wall:lumen ratio of the vessels and proliferation of smooth muscle cells. These vascular changes were attenuated by either valsartan, an AT(1) receptor antagonist, at a dose of 30 mg. kg(-1). d(-1) by gavage, or PD123319, an AT(2) receptor antagonist, at a dose of 830 ng/min by intraperitoneally implanted osmotic minipumps. Ang II infusion was associated with hypertension, which was prevented by valsartan, but not PD123319. (125)I-Sar(1), Ile(8) Ang II binding to mesenteric vasculature was increased after Ang II infusion. Valsartan treatment was associated with reduced Ang II binding to both receptor subtypes, whereas PD123319 was associated with reduced Ang II binding to only the AT(2) receptor subtype. These findings suggest that the trophic and proliferative effects of Ang II on the mesenteric vasculature are mediated by both AT(1) and AT(2) receptors.
Cao et al. (Wed,) conducted a other in Angiotensin II-induced mesenteric vascular hypertrophy. Valsartan or PD123319 vs. Ang II infusion alone was evaluated on Mesenteric vascular hypertrophy and smooth muscle cell proliferation. Valsartan and PD123319 both attenuated Ang II-induced mesenteric vascular hypertrophy, suggesting that the trophic and proliferative effects of Ang II are mediated by both AT1 and AT2 receptors.