Please use this identifier to cite or link to this item:
|The antilipolytic effect of insulin and epidermal growth factor in rat adipocytes are mediated by different mechanisms
|Tebar Ramon, Francesc
Soley i Farrés, María
Ramírez i Sunyer, Josep Ignasi
Factors de creixement
|Association for the Study of Internal Secretions
|Epidermal growth factor (EGF) and insulin induced similar effects in isolated rat adipocytes. To determine whether EGF and insulin produced similar effects through the same mechanisms, we focused on lipolysis. Insulin inhibited the lipolysis stimulated by isoproterenol, glucagon (either alone or in combination with adenosine deaminase), adenosine deaminase itself, or forskolin. In contrast, EGF did not inhibit the lipolysis stimulated by forskolin or by hormones when the cells were also incubated with adenosine deaminase. The effect of insulin, but not that of EGF, on isoproterenol-stimulated lipolysis disappeared when adipocytes were incubated with 1 microM wortmannin. These results indicate that EGF and insulin affected lipolysis through different mechanisms. We observed that EGF, but not insulin, increased cytosolic Ca2+. The effect of EGF, but not that of insulin, disappeared when the cells were incubated in a Ca2+-free medium. We suggest that EGF, but not insulin, mediate its antilipolytic effect through a Ca2+-dependent mechanism which, however, do not involve Ca2+-activated protein kinase C isoforms. This is based on the following: 1) phorbol 12-myristate 13-acetate affected lipolysis in an opposite way to that of EGF; and 2) the protein kinase C inhibitor bisindolylmaleimide GF 109203X did not affect the antilipolytic action of EGF. Our results indicate that the antilipolytic effect of EGF resembles more that of vasopressin than that of insulin.
|Reproducció del document publicat a: http://dx.doi.org/10.1210/en.137.10.4181
|It is part of:
|Endocrinology, 1996, vol. 137, num. 10, p. 4181-4188
|Appears in Collections:
|Articles publicats en revistes (Biomedicina)
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.