|
|
Enhanced regional AT2-receptor and PKC expression during cardioprotection induced by AT1-receptor blockade after reperfused myocardial infarction
Bodh I Jugdutt
Cardiology Division, Department of Medicine, University of Alberta, Edmonton, Alberta, bjugdutt{at}ualberta.ca
Mohammed Balghith
Cardiology Division, Department of Medicine, University of Alberta, Edmonton, Alberta
We assessed the effects of the angiotensin II (Ang II) type 1 receptor (AT1-receptor) blocker, candesartan, (CN, 1 mg/kg i.v. over 30 minutes pre-ischaemia) alone or after intracoronary administration of Ang II type 2 receptor (AT 2-receptor) blocker (PD 123319), protein kinase C (PKC) inhibitor (chelerythrine), endothelial nitric oxide (NO) synthase inhibitor (NG-monomethyl-L-arginine or L-NMMA), and bradykinin (BK) -B2 receptor inhibitor (HOE140) on in vivo left ventricular (LV) function and remodelling (echocardiograms/ Doppler) and haemodynamics in 30 dogs with reperfused anterior infarction (90 minutes ischaemia, 120 minutes reperfusion), and ex vivo infarct size, AT1-receptor/AT2-receptor proteins and PKC (immunoblots), and cyclic guanosine 3', 5' monophosphate (cGMP, immunoassay). Compared with controls, CN inhibited the Ang II pressor response, reduced LV preload, improved LV systolic and diastolic function, limited LV remodelling, decreased infarct size, and increased AT2-receptor and PKC proteins in the infarct zone (IZ), and these responses were abrogated by PD 123319, chelerythrine, L-NMMA and HOE140. In addition, the increase in LV cGMP with CN was attenuated by PD 123319, L-NMMA and HOE140. The overall results suggest that AT2-receptor activation and signalling via BK, PKC and cGMP contribute to cardioprotection associated with AT1-receptor blockade during ischaemia-reperfusion injury.
Key Words: AT1-receptor AT2-receptor PKC cGMP ischaemia-reperfusion
Journal of Renin-Angiotensin-Aldosterone System, Vol. 2, No. 2,
134-140 (2001)
DOI: 10.3317/jraas.2001.015

CiteULike Connotea Del.icio.us Digg Reddit Technorati What's this?
This article has been cited by other articles:

|
 |

|
 |
 
D. Kumar, V. Menon, W. R. Ford, A. S. Clanachan, and B. I. Jugdutt
Effect of Angiotensin II lype 2 Receptor Blockade on Activation of Mitogen-Activated Protein Kinases after Ischemia-Reperfusion in Isolated Working Rat Hearts
Journal of Cardiovascular Pharmacology and Therapeutics,
December 1, 2003;
8(4):
285 - 296.
[Abstract]
[PDF]
|
 |
|

|
 |

|
 |
 
B. I. Jugdutt and V. Menon
Upregulation of Angiotensin II Type 2 Receptor and Limitation of Myocardial Stunning by Angiotensin II Type 1 Receptor Blockers during Reperfused Myocardial Infarction in the Rat
Journal of Cardiovascular Pharmacology and Therapeutics,
September 1, 2003;
8(3):
217 - 226.
[Abstract]
[PDF]
|
 |
|
|
|