Effect of Swimming at Low Temperature on Uncoupling Protein Gene Expression in Skeletal Muscle of Wistar Rats

As the economy develops and living standards improve, overweight and obesity are increasingly prevalent. Currently, weight-loss medications are primarily administered orally or intravenously, which can result in poor targeting, low bioavailability, frequent administration, and high toxicity and side effects. The study aimed to address these challenges by preparing polylactic acid-polyethylene glycol staple fibers that carry the browning drug pioglitazone hydrochloride using electrostatic spinning and freeze-cutting techniques. Animal experiments were conducted to test the effectiveness of these fibers. Additionally, the study investigated the expression of uncoupling protein genes in rats exposed to different water temperatures by measuring changes in serum urea nitrogen and mRNA expression levels of skeletal muscle uncoupling protein genes. The physiological and genetic effects of low-temperature swimming exercise on changes in energy metabolism in rats were also analyzed at both the individual and molecular levels. The results revealed that serum urea nitrogen remained more stable in hypothermic swimming rats compared to rats in the swimming group. Furthermore, the study observed an induced up-regulation of uncoupling proteins in the skeletal muscle of Wistar rats in response to external temperature stimulation, and the expression of mRNA for skeletal muscle uncoupling proteins significantly increased as the temperature decreased. And the prepared short nanofibers also had a significant promotive effect on uncoupling protein gene, COX7A1, while suppressing the expression of lipogenic gene.