1992 Volume 38 Pages 122-127
Our hibernation studies on mammals started from the physiological finding that Ca ion regulatory system of cardiac muscles from chipmunks, a mammalian hibernator, was markedly changed for preparation for hibernation. From this evidence, the existence of an endogenous factor related to hibernation was assumed and four types of protein specific for hibernation were identified in the blood of chipmunks. These proteins (HP-20, 25, 27 and 55) were markedly reduced from the blood before, and during hibernation. HP-20, 25 and 27 are homologous and a novel type of protein, while HP-55 is similar to α_1-antitrypsin. These novel proteins were detected only in hibernating species in the squirrel family. In the present paper, our recent studies on the heart function and the blood proteins specific for hibernation were reviewed.
