title: Effect of cold acclimation on glucagon receptors of rat white adipocytes.
abstract: In order to determine the role of glucagon in cold acclimation, the changes in glucagon receptor were investigated in white adipocytes from cold-acclimated rats by establishing a glucagon radioreceptor assay method for isolated white adipocytes. The following conditions were found to be appropriate for specific glucagon receptor binding assay; cell concentration of about 1 X 10(5) cells/ml, 15 min preincubation with glucagon and 30 min-reaction at 25 degrees C in the presence of bacitracin (1 mg/ml). Cold acclimation decreased the size and increased the number of epididymal white adipocytes. Cold acclimation increased the number of glucagon receptors of white adipocytes, resulting in 140% in terms of unit cell, and 260% increase per unit surface area and 210% increase per whole tissue. However, the affinity of the binding site for glucagon was not affected. The results suggested that an enhanced metabolic response of cold-acclimated rats to glucagon could be partly explained by the increased number of glucagon receptor in white adipocytes.
mesh_terms: D000222:Adaptation, Physiological; D000273:Adipose Tissue / Q000502:physiology*; D000818:Animals; D001414:Bacitracin / Q000494:pharmacology; D003080:Cold Temperature; D005934:Glucagon / Q000378:metabolism; D007700:Kinetics; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D011964:Receptors, Gastrointestinal Hormone / Q000502:physiology*; D018027:Receptors, Glucagon; D013997:Time Factors
chemical_list: D011964:Receptors, Gastrointestinal Hormone; D018027:Receptors, Glucagon; D001414:Bacitracin; D005934:Glucagon