Hormonal regulation of adipose S-100 protein release.
The release of S-100 protein from epididymal fat pads was enhanced by epinephrine in vitro, and about 50% of S-100 protein in the tissue was released into the medium after 2-h incubation at 37 degrees C with 10 microM epinephrine. Similar results were obtained with the incubation of isolated adipocytes. The S-100 protein release was also enhanced by isoproterenol, norepinephrine, ACTH, and dibutyryl cyclic AMP, which all increase the lipolysis by increasing cyclic AMP levels in the tissue. Propranolol, a beta-adrenergic blocker, could block the increase of S-100 protein release by catecholamines, indicating that the release was mediated by the beta-adrenergic effect of catecholamines. However propranolol had no suppressive effect on the enhancement of S-100 protein release by ACTH or dibutyryl cyclic AMP. Insulin had an inhibitory effect on the epinephrine-enhanced S-100 protein release. Epinephrine or ACTH could not stimulate the S-100 protein release in the absence of Ca2+, whereas the epinephrine-enhanced glycerol release was not affected under the same conditions. The increase in S-100 protein release was induced by only a pretreatment of the tissue with epinephrine. However, the lipolysis in the tissue was not enhanced by the pretreatment alone. These results indicate that the release of S-100 protein from adipocytes is regulated by the hormones that have been known to control the lipolysis with a manner slightly different from that of lipolysis.
D000273:Adipose Tissue / Q000187:drug effects / Q000378:metabolism*; D000324:Adrenocorticotropic Hormone / Q000494:pharmacology; D000818:Animals; D003994:Bucladesine / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology; D004822:Epididymis / Q000378:metabolism; D004837:Epinephrine / Q000494:pharmacology; D005990:Glycerol / Q000378:metabolism; D006728:Hormones / Q000494:pharmacology*; D007545:Isoproterenol / Q000494:pharmacology; D008066:Lipolysis; D008297:Male; D009638:Norepinephrine / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D009418:S100 Proteins / Q000378:metabolism*
D006728:Hormones; D009418:S100 Proteins; D003994:Bucladesine; D000324:Adrenocorticotropic Hormone; D011433:Propranolol; D007545:Isoproterenol; D005990:Glycerol; D002118:Calcium; D009638:Norepinephrine; D004837:Epinephrine