Published May 1986 | Version v1
Journal article

Insulin alters cAMP-activated lipolysis but not cAMP-inhibited glycogen synthase in permeabilized adipocytes

  • 1. Univ. of Rochester School of Medicine and Dentistry, NY

Description

Lipolysis and, to a lesser extent, glycogen synthase activity are regulated in adipocytes by cellular cAMP and counter-regulated by insulin. These activities were measured in situ in digitonin (20 μg/ml) permeabilized rat adipocytes. Incorporation of 3H UDP-glucose into endogenous glycogen in the presence of KF, EDTA and 10mM glucose-6-phosphate was the basis of the G.S. assay. Cellular GS activity determined by this technique was 1.4 +/- 0.2 fold greater than that of matched homogenates. Insulin treatment of intact cells prior to permeabilization increased GS activity ratio (-/+ G-6-P) 2.5 fold when subsequently measured by the in situ assay. Following digitonin permeabilization, addition of cAMP to the suspension medium increased lipolysis 7 fold and decreased GS activity ratio to 0.38 +/- 0.01 from a basal value of 0.44 +/- 0.06. ATP had a negligible effect on lipolysis but decreased GS to 0.16 +/- 0.04. ATP plus cAMP was only slightly more effective on GS than ATP alone. Insulin at 10-9M inhibited cAMP-dependent lipolysis by 27% but had no effect on the cAMP- or ATP-dependent decrease in GS. These results suggest that insulin's counter-regulatory mechanisms on these two cAMP-dependent processes may be different

Additional details

Publishing Information

Journal Title
Fed. Proc., Fed. Am. Soc. Exp. Biol.
Journal Volume
45
Journal Issue
6
Journal Series
Fed. Proc., Fed. Am. Soc. Exp. Biol.
Journal Page Range
1686
ISSN
0014-9446
CODEN
FEPRA

Conference

Title
76. annual meeting of the Federation of American Society for Experimental Biology.
Dates
8-12 Jun 1986.
Place
Washington, DC (USA).

INIS

Country of Publication
United States
Country of Input or Organization
United States
INIS RN
18022892
Subject category
APPLIED LIFE SCIENCES;
Resource subtype / Literary indicator
Conference
Quality check status
Yes
Descriptors DEI
AMP; BIOLOGICAL EFFECTS; ENZYME ACTIVITY; FAT CELLS; GLUCOSE; HOMOGENATES; INSULIN; LIGASES; METABOLISM; RATS; TRACER TECHNIQUES; TRITIUM COMPOUNDS;
Descriptors DEC
ALDEHYDES; ANIMAL CELLS; ANIMALS; CARBOHYDRATES; CONNECTIVE TISSUE CELLS; ENZYMES; HEXOSES; HORMONES; HYDROGEN COMPOUNDS; ISOTOPE APPLICATIONS; MAMMALS; MONOSACCHARIDES; NUCLEOTIDES; ORGANIC COMPOUNDS; PEPTIDE HORMONES; RODENTS; SACCHARIDES; SOMATIC CELLS; VERTEBRATES;

Optional Information

Secondary number(s)
CONF-8606151--.