First Author | Cervenka L | Year | 2008 |
Journal | J Hypertens | Volume | 26 |
Issue | 7 | Pages | 1379-89 |
PubMed ID | 18551014 | Mgi Jnum | J:279763 |
Mgi Id | MGI:6367542 | Doi | 10.1097/HJH.0b013e3282fe6eaa |
Citation | Cervenka L, et al. (2008) Pivotal role of angiotensin II receptor subtype 1A in the development of two-kidney, one-clip hypertension: study in angiotensin II receptor subtype 1A knockout mice. J Hypertens 26(7):1379-89 |
abstractText | OBJECTIVE: The present study was performed to examine in two-kidney, one-clip (2K1C) Goldblatt hypertensive mice: first, the relative contribution of angiotensin II receptor subtypes 1A (AT(1A)) and 1B (AT(1B)); second, the role of angiotensin II type 2 (AT(2)) receptors in the development of hypertension in wild-type (AT(1A)+/+) and AT(1A) receptor knockout (AT(1A)-/-) mice; and third, the role of increased nitric oxide synthase activity in counteracting the hypertensinogenic action of angiotensin II in this model. METHODS: AT(1A)+/+ and AT(1A)-/- mice underwent clipping of one renal artery and were infused with either saline vehicle or selective AT(2) receptor agonist CGP-42112A (CGP). Blood pressure was monitored by radiotelemetry. Blood pressure responses to the nitric oxide synthase inhibitor nitro-L-arginine-methyl-ester were evaluated. RESULTS: AT(1A)+/+ mice responded to clipping by a rise in blood pressure that was not modified by CGP infusion. Clip placement caused a slight increase in blood pressure in AT(1A)-/- mice that remained significantly lower than in AT(1A)+/+ mice. Acute nitric oxide synthase inhibition caused greater increase in blood pressure in 2K1C/AT(1A)+/+ than in AT(1A)+/+ mice. CONCLUSION: The present data support the critical role of AT(1A) receptors in the development of 2K1C hypertension, whereas AT(1B) receptors play only a minor role in blood pressure regulation in this model of angiotensin II-dependent hypertension. Activation of AT(2) receptors does not play an antagonistic role in the AT(1) receptor-mediated hypertensinogenic actions of angiotensin II in this model. Finally, enhanced nitric oxide synthase activity plays a protective role by counteracting the vasoconstrictor influences of angiotensin II in 2K1C hypertensive mice. |