The Effect of Calcium on Purified Human Adipose Tissue "I" Form Glycogen Synthetase: A Possible Mechanism of Hormonal Regulation

Abstract

glycerol, known to disturb carbohydratc tolerancc (Schalch and Kipnis 1965). The highly significant increasc in blood glycerol associated with the overnight fast reflccts a marked lipolytic response to starvation. This increase is more pronounced than the incrcasc rcgistercd in connection with sacrifice stress in the previous study. Acknowlcdgcments Supported by grants from Götcborg Mcdical Society and Swedish Medical Council (B75-19X-251). Refercncc,

Calcium as a Mediator of Hormone Action

“…The enzyme has also been reported to be activated by CaZ+ in the ,UM concentration range in liver (Khoo & Steinberg, 1975;Shimazu & Amakawa, 1975), but the properties of the enzyme in adipose tissue are not yet clear (Khoo et al, 1973;Khoo, 1976;Khoo & Steinberg, 1975). The ability of PM concentrations of Ca2+ to activate adipose-tissue glycogen synthase (Hope-Gill, 1976) and to inhibit triglyceride lipase has been reported. Adiposetissue pyruvate dehydrogenase phosphatase, a mitochondrial enzyme, has been shown to require Ca2+ at 0.1-10pM (Denton et al, 1972; Severson et al, 1974).…”