Dataset Information

Angiotensin II promotes development of the renal microcirculation through AT1 receptors.

ABSTRACT: Pharmacologic or genetic deletion of components of the renin-angiotensin system leads to postnatal kidney injury, but the roles of these components in kidney development are unknown. To test the hypothesis that angiotensin II supports angiogenesis during postnatal kidney development, we quantified CD31(+) postglomerular microvessels, performed quantitative PCR analysis of vascular growth factor expression, and measured renal blood flow by magnetic resonance. Treating rats with the angiotensin II type 1 receptor antagonist candesartan for 2 weeks after birth reduced the total length, volume, and surface area of capillaries in both the cortex and the medulla and inhibited the organization of vasa recta bundles. In addition, angiotensin II type 1 antagonism inhibited the transcription of angiogenic growth factors vascular endothelial growth factor, angiopoietin-1, angiopoietin-2, and the angiopoietin receptor Tie-2 in cortex and medulla. Similarly, Agtr1a(-/-);Agtr1b(-/-) mouse kidneys had decreased angiopoietin-1, angiopoietin-2, and Tie-2 mRNAs at postnatal day 14. To test whether increased urinary flow leads to microvascular injury, we induced postnatal polyuria with either lithium or adrenalectomy, but these did not alter vascular endothelial growth factor expression or vasa recta organization. Compared with vehicle-treated rats, renal blood flow was significantly (approximately 20%) lower in candesartan-treated rats even 14 days after candesartan withdrawal. Taken together, these data demonstrate that angiotensin II promotes postnatal expansion of postglomerular capillaries and organization of vasa recta bundles, which are necessary for development of normal renal blood flow.

SUBMITTER: Madsen K

PROVIDER: S-EPMC2831863 | biostudies-other | 2010 Mar

REPOSITORIES: biostudies-other

ACCESS DATA

Publications

Angiotensin II promotes development of the renal microcirculation through AT1 receptors.

Madsen Kirsten K Marcussen Niels N Pedersen Michael M Kjaersgaard Gitte G Facemire Carie C Coffman Thomas M TM Jensen Boye L BL

Journal of the American Society of Nephrology : JASN 20100107 3

Pharmacologic or genetic deletion of components of the renin-angiotensin system leads to postnatal kidney injury, but the roles of these components in kidney development are unknown. To test the hypothesis that angiotensin II supports angiogenesis during postnatal kidney development, we quantified CD31(+) postglomerular microvessels, performed quantitative PCR analysis of vascular growth factor expression, and measured renal blood flow by magnetic resonance. Treating rats with the angiotensin II ...[more]

PMID: 20056745

Similar Datasets

Project description:Adiponectin, an abundant adipose tissue-derived protein, exerts protective effect against cardiovascular disease. Adiponectin receptors (AdipoR1 and AdipoR2) mediate the beneficial effects of adiponectin on the cardiovascular system. However, the alteration of AdipoRs in cardiac remodeling is not fully elucidated. Here, we investigated the effect of angiotensin II (AngII) on cardiac AdipoRs expression and explored the possible molecular mechanism. AngII infusion into rats induced cardiac hypertrophy, reduced AdipoR1 but not AdipoR2 expression, and attenuated the phosphorylations of adenosine monophosphate-activated protein kinase and acetyl coenzyme A carboxylase, and those effects were all reversed by losartan, an AngII type 1 (AT1) receptor blocker. AngII reduced expression of AdipoR1 mRNA and protein in cultured neonatal rat cardiomyocytes, which was abolished by losartan, but not by PD123319, an AT2 receptor antagonist. The antioxidants including reactive oxygen species (ROS) scavenger NAC, NADPH oxidase inhibitor apocynin, Nox2 inhibitor peptide gp91 ds-tat, and mitochondrial electron transport chain complex I inhibitor rotenone attenuated AngII-induced production of ROS and phosphorylation of extracellular signal-regulated kinase (ERK) 1/2. AngII-reduced AdipoR1 expression was reversed by pretreatment with NAC, apocynin, gp91 ds-tat, rotenone, and an ERK1/2 inhibitor PD98059. Chromatin immunoprecipitation assay demonstrated that AngII provoked the recruitment of c-Myc onto the promoter region of AdipoR1, which was attenuated by PD98059. Moreover, AngII-induced DNA binding activity of c-Myc was inhibited by losartan, NAC, apocynin, gp91 ds-tat, rotenone, and PD98059. c-Myc small interfering RNA abolished the inhibitory effect of AngII on AdipoR1 expression. Our results suggest that AngII inhibits cardiac AdipoR1 expression in vivo and in vitro and AT1 receptor/ROS/ERK1/2/c-Myc pathway is required for the downregulation of AdipoR1 induced by AngII.

Dataset Information

Angiotensin II promotes development of the renal microcirculation through AT1 receptors.

Publications

Angiotensin II promotes development of the renal microcirculation through AT1 receptors.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets