Figure 3

Cardiac fibrosis and gene expression. (a) Collagen deposition as revealed by Azan–Mallory staining in perivascular (upper panels) or interstitial (lower panels) regions of the LV myocardium of DS/lean and DS/obese rats at 15 weeks of age. Scale bars, 200 μm. (b, c) Relative extents of perivascular and interstitial fibrosis, respectively, in the LV myocardium as determined from sections similar to those in (a). (d–g) Quantitative real-time (RT) PCR analysis of collagen type I, collagen type III, TGF-β1, and CTGF mRNAs in the left ventricle of DS/lean and DS/obese rats at 15 weeks of age, respectively. The amount of each mRNA was normalized by that of 18S rRNA and then expressed relative to the mean value for DS/lean rats. Data in (b) through (g) are means±s.e.m. for surviving animals (n=10 and 14 for DS/lean and DS/obese rats, respectively). *P<0.05 vs. DS/lean rats.