Cold-resistant mice with "bird" muscles

Mammals react to a decrease in ambient temperature by increasing the production of heat (thermogenesis) through mechanisms such as trembling and splitting of "brown fat" consisting of energy-rich fat cells contained in large numbers in the organisms of newborns and hibernating animals.

Researchers at two Colorado State universities – in Denver and Boulder – created mice whose muscles were characterized by increased expression of the lipoprotein lipase enzyme, which extracts fat molecules from the bloodstream and, thus, ensures their use as raw materials for heat production instead of carbohydrates. When such animals were placed in a chamber in which a temperature of about 4 degrees Celsius was maintained, they tolerated the cold much better than ordinary mice of the control group and in such conditions maintained a normal body temperature for several hours.

This resistance is due to the ability of lipoprotein lipase to enhance the processes of fat oxidation in muscles, which allows you to produce more heat without increasing physical activity. This mechanism is not typical for mammals, but is used to maintain body temperature by birds that do not have brown fat.

Article by Dalan R. Jensen et al. Increased thermoregulation in cold-exposed transgenic mice overexpressing lipoprotein lipase in skeletal muscle: an avian phenotype? published in the April issue of the Journal of Lipid Research.

Portal "Eternal youth" www.vechnayamolodost.ru based on the materials of ScienceDaily

18.03.2008