Fig. 2.

Aging downregulates SM contractile and regulatory protein expression in rat IAS. A: RNA and protein were extracted from 6-, 18-, and 26-mo-old rat IAS SMCs and subjected to RT-PCR (left) and immunoblot (right) analysis for the indicated proteins. Representative blots from 4 independent experiments are presented. B: graph showing significant decrease in the relative expression (*P < 0.05; n = 4; Student's t-test) of different proteins (corresponding to the mRNAs described in Fig. 1) in 26-mo-old vs. 6-mo-old rats compared with younger rats.