Localization of angiotensin-II type 1(AT1) receptors on buffalo spermatozoa: AT1 receptor activation during capacitation triggers rise in cyclic AMP and calcium

2014 ◽  
Vol 41 (4) ◽  
pp. 1959-1965 ◽  
Author(s):  
Sivaram Vedantam ◽  
Rita Rani ◽  
Monica Garg ◽  
Suresh K. Atreja
Keyword(s):  
Angiotensin Ii ◽  
Cyclic Amp ◽  
Receptor Activation ◽  
At1 Receptor ◽  
At1 Receptors

scholarly journals Enhanced hemodynamic responses to angiotensin II in diabetes are associated with increased expression and activity of AT1 receptors in the afferent arteriole

2017 ◽  
Vol 49 (10) ◽  
pp. 531-540 ◽  
Author(s):  
Jie Zhang ◽  
Helena Y. Qu ◽  
Jiangping Song ◽  
Jin Wei ◽  
Shan Jiang ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Mrna Level ◽  
At1 Receptor ◽  
Receptor Expression ◽  
Ang Ii ◽  
Diabetic Mice ◽  
At1 Receptors ◽  
Enhanced Expression ◽  
Bolus Intravenous Injection

The prevalence of hypertension is about twofold higher in diabetic than in nondiabetic subjects. Hypertension aggravates the progression of diabetic complications, especially diabetic nephropathy. However, the mechanisms for the development of hypertension in diabetes have not been elucidated. We hypothesized that enhanced constrictive responsiveness of renal afferent arterioles (Af-Art) to angiotensin II (ANG II) mediated by ANG II type 1 (AT1) receptors contributes to the development of hypertension in diabetes. In response to an acute bolus intravenous injection of ANG II, alloxan-induced diabetic mice exhibited a higher mean arterial pressure (MAP) (119.1 ± 3.8 vs. 106.2 ± 3.5 mmHg) and a lower renal blood flow (0.25 ± 0.07 vs. 0.52 ± 0.14 ml/min) compared with nondiabetic mice. In response to chronic ANG II infusion, the MAP measured with telemetry increased by 55.8 ± 6.5 mmHg in diabetic mice, but only by 32.3 ± 3.8 mmHg in nondiabetic mice. The mRNA level of AT1 receptor increased by ~10-fold in isolated Af-Art of diabetic mice compared with nondiabetic mice, whereas ANG II type 2 (AT2) receptor expression did not change. The ANG II dose-response curve of the Af-Art was significantly enhanced in diabetic mice. Moreover, the AT1 receptor antagonist, losartan, blocked the ANG II-induced vasoconstriction in both diabetic mice and nondiabetic mice. In conclusion, we found enhanced expression of the AT1 receptor and exaggerated response to ANG II of the Af-Art in diabetes, which may contribute to the increased prevalence of hypertension in diabetes.

Angiotensin II type 1 receptor-mediated stimulation of c-fos gene expression in astroglial cultures

1993 ◽  
Vol 265 (4) ◽  
pp. C1046-C1049 ◽  
Author(s):  
M. K. Raizada ◽  
B. Rydzewski ◽  
D. Lu ◽  
C. Sumners
Keyword(s):  
Gene Expression ◽  
Angiotensin Ii ◽  
Receptor Activation ◽  
At1 Receptor ◽  
Mrna Levels ◽  
Ang Ii ◽  
Astroglial Cells ◽  
Pai 1 ◽  
Stimulation Of

Angiotensin II (ANG II) stimulates plasminogen activator inhibitor 1 (PAI-1) gene expression in astroglial cells prepared from rat brains. In this study, we investigated whether c-fos gene expression may be involved in this cellular action of ANG II. Incubation of astroglial cultures with ANG II caused a time- and dose-dependent transient stimulation of the steady-state levels of c-fos mRNA, with a maximal stimulation of 50-fold observed with 100 nM ANG II within 30-45 min. This stimulation was completely abolished by the presence of the type 1 ANG II (AT1) receptor antagonist losartan but not by the type 2 ANG II receptor blocker PD-123177. Depolarization of brain cell cultures with 50 mM K+ also caused a 100-fold increase in c-fos mRNA levels, an effect partially blocked by losartan. These observations show that AT1 receptor activation stimulates expression of the c-fos gene, which may act as a third messenger in the regulation of cellular actions of ANG II, including PAI-1 gene expression in astroglial cells.

A novel mechanism of mechanical stress-induced angiotensin II type 1–receptor activation without the involvement of angiotensin II

2007 ◽  
Vol 377 (4-6) ◽  
pp. 393-399 ◽  
Author(s):  
Noritaka Yasuda ◽  
Hiroshi Akazawa ◽  
Yingjie Qin ◽  
Yunzeng Zou ◽  
Issei Komuro
Keyword(s):  
Angiotensin Ii ◽  
Mechanical Stress ◽  
Receptor Activation

Lipid signal transduction pathways in angiotensin II type 1 receptor-transfected fibroblasts

1995 ◽  
Vol 269 (2) ◽  
pp. C435-C442 ◽  
Author(s):  
Y. Wen ◽  
M. C. Cabot ◽  
E. Clauser ◽  
S. L. Bursten ◽  
J. L. Nadler
Keyword(s):  
Signal Transduction ◽  
Angiotensin Ii ◽  
Chinese Hamster ◽  
Receptor Activation ◽  
Signal Transduction Pathways ◽  
Ang Ii ◽  
Vascular Type ◽  
Lipid Signal ◽  
Fibroblast Line

A stable Chinese hamster ovary fibroblast line expressing the rat vascular type 1a angiotensin II (ANG II) receptor was used to study the lipid-derived signal transduction pathways elicited by type 1a ANG II receptor activation. ANG II caused a biphasic and dose-dependent increase in diacylglycerol (DAG) accumulation with an initial peak at 15 s (181 +/- 11% of control, P < 0.02) and a second sustained peak at 5-10 min (214 +/- 10% of control, P < 0.02). The late DAG peak was derived from phosphatidylcholine (PC), and the formation was blocked by ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid. ANG II also increased phosphatidic acid (PA) production nearly fourfold by 7.5 min. In the presence of ethanol, ANG II markedly increased phosphatidylethanol (PEt) formation, indicating activation of phospholipase D (PLD). ANG II was shown to increase the mass of three separate PA species, one of which apparently originated from DAG kinase action on PC-phospholipase C (PLC)-produced DAG, providing evidence for PC-PLC activity. ANG II also formed a third PA species, which originated neither from PLD nor from DAG kinase. These results demonstrate that multiple lipid signals propagated via collateral stimulation of PLC and PLD are generated by specific activation of the vascular type 1a ANG II receptor.

Involvement of Runx3 in the basal transcriptional activation of the mouse angiotensin II type 1 receptor-associated protein gene

2011 ◽  
Vol 43 (14) ◽  
pp. 884-894 ◽  
Author(s):  
Miyuki Matsuda ◽  
Kouichi Tamura ◽  
Hiromichi Wakui ◽  
Toru Dejima ◽  
Akinobu Maeda ◽  
...  
Keyword(s):  
Gene Expression ◽  
Angiotensin Ii ◽  
Transcriptional Activation ◽  
At1 Receptor ◽  
Distal Convoluted Tubule ◽  
Luciferase Assay ◽  
Serum Starvation ◽  
Receptor Associated Protein ◽  
Tubule Cells

We previously cloned a molecule that interacts with angiotensin II type 1 (AT1) receptor to exert an inhibitory function on AT1 receptor signaling that we named ATRAP/ Agtrap (for AT1 receptor-associated protein). In the present study we examined the regulation of basal ATRAP gene expression using renal distal convoluted tubule cells. We found that serum starvation upregulated basal expression of ATRAP gene, a response that required de novo mRNA and protein synthesis. Luciferase assay revealed that the proximal promoter region directs transcription and that a putative binding site of runt-related transcription factors (RBE) is important for transcriptional activation. The results of RBE-decoy transfection and endogenous knockdown by small interference RNA showed that the runt-related transcription factor Runx3 is involved in ATRAP gene expression. Chromatin immunoprecipitation assay also supported the binding of Runx3 to the ATRAP promoter in renal distal convoluted tubule cells. Immunohistochemistry demonstrated the expression of Runx3 and ATRAP proteins in the distal convoluted and connecting tubules of the kidney in consecutive sections. Furthermore, the Runx3 immunostaining was decreased together with a concomitant suppression of ATRAP expression in the affected kidney after 7 days of unilateral ureteral obstruction. These findings indicate that Runx3 plays a role in ATRAP gene expression in renal distal tubular cells both in vitro and in vivo.

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