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P Belfrage

Publications and source records attributed to P Belfrage.

160 records · Page 9Linked to original sources
PubMed1970

Activation of hormone-sensitive lipase in extracts of adipose tissue.

Rat adipose tissue was homogenized in 0.154 m KCl, and the supernatant fluid, obtained after centrifugation at 15,000 g, was extracted with benzene to remove triglycerides. Most of the lipase activity in the extracted fluid was precipitated with ammonium sulfate between 15 and 40% saturation. The specific activity of the lipase in this fraction was about three times that in the benzene-extracted supernatant fluid. The specific activity of the monoglyceride esterase was increased to a lesser extent. Lipase activity in the benzene-extracted fluid and in the ammonium sulfate fraction was increased 15-45% by incubation with 0.3 mm ATP, 10 mm MgCl(2), and 0.03 mm cyclic AMP for 10 min before assay. None of these compounds alone or in combinations of two was as effective as all three together. The specific activity of the 15-40% ammonium sulfate fraction prepared from fat cells exposed to epinephrine and glucagon was greater than that from portions of the same cell pool not exposed to hormones. In addition, the already elevated lipase activity in preparations from hormone-treated cells was not enhanced by incubation with ATP, MgCl(2), and cyclic AMP. Thus, it seems probable that the lipase activity in the ammonium sulfate fractions represents, at least in part, hormone-sensitive lipase.

Adenosine Triphosphate↗
PubMed1969

Simple liquid-liquid partition system for isolation of labeled oleic acid from mixtures with glycerides.

Oleic acid has a partition coefficient, upper phase/lower phase, of 1.9 (22 degrees C) in the liquid-liquid partition system described herein. Tri-, di-, and monoolein are found almost exclusively in the lower (organic) phase. Oleic acid can be quantitatively removed from mixtures of triglyceride and partial glycerides by means of this partition system under conditions resembling those in a lipase assay.

Animals↗