In vitro influence of oxygenation on enzymes of rat adipose tissue.
Pre-incubation of rat adipose tissue from ad lib fed rats in the presence of 1.2 U/ml insulin and 2.8 x 10(-7) M prostaglandin F2 alpha for 16 hours in a gas atmosphere of 5% O2 led to an increase in glucose-6-phosphate dehydrogenase activity. No increase in glycerol-3-phosphate dehydrogenase or hexokinase activities were noted. Actinomycin D (50 micrograms/ml) and dehydroepiandrosterone (120 micrograms/ml) attenuated this increase and the increase in incorporation of [1-14C] glucose into carbon dioxide and tissue seen under these conditions. No increase in glucose-6-phosphate dehydrogenase was seen when pre-incubation was made in a gas atmosphere containing 20% O2. Although dehydroepiandrosterone inhibited both enzyme activity and isotope incorporation in a 20% O2 gas atmosphere, actinomycin D was without effect.