Cellular and molecular mechanisms of tissue protection by lipophilic calcium channel blockers

Item Type:	Article
Title:	Cellular and molecular mechanisms of tissue protection by lipophilic calcium channel blockers
Creators Name:	Menne, J. and Park, J.K. and Agrawal, R. and Lindschau, C. and Kielstein, J.T. and Kirsch, T. and Marx, A. and Muller, D. and Bahlmann, F.H. and Meier, M. and Bode-Böger, S.M. and Haller, H. and Fliser, D.
Abstract:	Long-acting third-generation dihydropyridine calcium channel blockers (CCBs) improve endothelial dysfunction and prevent cardiovascular events in humans, but their cellular and molecular mechanisms of tissue protection are not elucidated in detail. We assessed organ (renal) protection by the highly lipophilic CCB lercanidipine in a double-transgenic rat (dTGR) model with overexpression of human renin and angiotensinogen genes. We randomly treated dTGR with lercanidipine (2.5 mg/kg/day; n=20) or vehicle (n=20) for 3 wk. Furthermore, we explored the influence of lercanidipine on protein kinase C (PKC) signaling in vivo and in vitro using endothelial and vascular smooth muscle cell cultures. Cumulative mortality was 60% in untreated dTGR, whereas none of the lercanidipine-treated animals died (P<0.001). We found significantly less albuminuria and improved renal function in lercanidipine-treated dTGR (both P<0.05). Lercanidipine treatment also significantly (P<0.05) reduced blood levels of the endogenous NOS inhibitor asymmetric dimethylarginine. On histological examination, we observed significantly less tissue inflammation and fibrosis in lercanidipine-treated animals (both P<0.05). Lercanidipine significantly inhibited angiotensin (ANG) I-mediated PKC-α and -δ activation in vivo and in vitro, partly due to reduced intracellular calcium flux. As a result, lercanidipine improved endothelial cell permeability in vitro. Lercanidipine prevents tissue injury and improves survival in a model of progressive organ damage. These effects may result, at least in part, from inhibition of tissue inflammation as well as improved NO bioavailability. Modulation of PKC activity may be an important underlying intracellular mechanism.
Keywords:	Angiotensin II, Protein Kinase C, Asymmetric Dimethylarginine, Lercanidipine, Animals, Rats
Source:	FASEB Journal
ISSN:	0892-6638
Publisher:	Federation of American Societies for Experimental Biology
Volume:	20
Number:	7
Page Range:	994-996
Date:	May 2006
Official Publication:	https://doi.org/10.1096/fj.05-4087fje
PubMed:	View item in PubMed

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