Arosio B, Perlini S, Calabresi C, Tozzi R, Palladini G, Ferrari AU, Vergani C, Annoni G. Adenosine A1 and A2A receptor cross-talk during ageing in the rat myocardium.
Exp Gerontol 2003;
38:855-61. [PMID:
12915207 DOI:
10.1016/s0531-5565(03)00095-0]
[Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Adenosine (Ado), a naturally occurring autacoid, exerts cardioprotective effects against myocardial ischemia and reperfusion injury, through activation of its receptors type 1 (A1) and 2A (A2A). Since ageing involves a complex change in these effects, we evaluated A1 and A2A gene expression in left (LV) and right ventricle (RV) from 2-, 5-, 12-, and 21-month-old Sprague-Dawley rats. LV end-diastolic (EDD) and end-systolic (ESD) internal dimensions (mm) and LV fractional shortening (FS, %) were measured by M-mode echocardiography. Senescence was associated with a reduction in FS (42+/-1, 38+/-2, 39+/-2 and 35+/-2, in 2-, 5-, 12- and 21-month-old rats; p<0.02) and increases in EDD (7.5+/-0.2, 8.1+/-0.2, 8.5+/-0.2 and 8.8+/-0.2; p<0.001) and ESD (4.2+/-0.1, 4.4+/-0.2, 4.7+/-0.2 and 5.1+/-0.2; p=0.002). Ado A1 mRNA levels were highest in 12 and 21-month-old animals in both ventricles (LV: p<0.001; RV: p=0.001). By contrast, Ado A2A gene expression was lower in the aged LV (p<0.001), but higher in the aged RV (p<0.001). These modifications of Ado receptor gene expression and especially the increase in A1 receptor mRNA may partially explain the stronger antiadrenergic effects of Ado in the senescent heart.
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