cDNA cloning and mRNA analysis of PGC-1 in epitrochlearis muscle in swimming-exercised rats

Peroxisome proliferator-activated receptor gamma coactivator-l (PGC-1), a c old-inducible coactivator of nuclear receptors, stimulates mitochondrial bi ogenesis and respiration in muscle cells, fn the present study, we first cl oned a rat PGC-1 gene from a brown adipose tissue cDNA library which encode s a predicted 796-amino-acid protein and exhibits respectively 98% and 95% identity with the mouse and human homologues. Next, we examined the effect of swimming exercise training on the level of expression of the PGC-1 gene in rat epitrochlearis (Epi) muscle. PGC-I mRNA level in Epi muscle in rats that swam 2 h a day for 3 and 7 days increased dramatically by 154% and 163 %, respectively, compared to the non-exercised control group. PGC-1 mRNA up -regulation was not observed in an immersion group treated at 35 degrees C during the training program but without swimming exercise. These results de monstrate that expression of the PGC-1 gene in Epi muscle is induced not on ly by cold exposure but also by prolonged low-intensity physical exercise. (C) 2000 Academic Press.