Stimulatory and cytotoxic effects of an antiserum to adipocyte plasma membranes on adipose tissue metabolism in vitro and in vivo.
Antibodies to rat adipocyte plasma membranes raised in sheep had a dual effect in vitro; at low concentrations they mimicked the actions of insulin whilst higher concentrations inhibited glucose incorporation into lipid. The insulin-like effects of the antibody appeared to be due to direct activation of the glucose transport system since the antibodies did not bind to the insulin receptor, as judged by their inability to immunoprecipitate the receptor or to inhibit insulin binding, and antibodies were able to stimulate glucose transport in cells which had had their insulin receptors removed by trypsinization. The inhibitory effects of the antiserum were due to cytotoxicity since, in the presence of antiserum, adipocytes began to release large quantities of the intracellular enzyme, lactate dehydrogenase, and were ultimately lysed. This cytotoxic effect of the antiserum was complement-dependent since heat-inactivated antiserum or a crude immunoglobulin fraction of the serum possessed only stimulatory effects on lipid metabolism. When injected into rats for 4 days the antiserum produced gross abnormality of adipose tissue depots. Dissolution of adipocytes and massive infiltration by lymphocytes and polymorphs were evident. Preliminary observations suggest that such treatment results in long-term reduction of the number of adipocytes in internal fat depots.
Flint
D J
DJ
Coggrave
H
H
Futter
C E
CE
Gardner
M J
MJ
Clarke
T J
TJ
D000273:Adipose Tissue / Q000378:metabolism* / Q000648:ultrastructure; D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002462:Cell Membrane / Q000276:immunology; D003602:Cytotoxicity, Immunologic / Q000187:drug effects*; D005260:Female; D005947:Glucose / Q000378:metabolism; D007106:Immune Sera / Q000494:pharmacology*; D007328:Insulin / Q000378:metabolism; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D050356:Lipid Metabolism; D009928:Organ Specificity / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D012756:Sheep; D005719:gamma-Globulins / Q000494:pharmacology
D007106:Immune Sera; D007328:Insulin; D005719:gamma-Globulins; D007770:L-Lactate Dehydrogenase; D005947:Glucose