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Lipid metabolism and secretory function of porcine intramuscular adipocytes compared with subcutaneous and perirenal adipocytes

Authors :
Florence Gondret
Delphine Gardan
Isabelle Louveau
Systèmes d'Elevage, Nutrition Animale et Humaine (SENAH)
Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Supérieure Agronomique de Rennes
Ecole Nationale Supérieure Agronomique de Rennes-Institut National de la Recherche Agronomique (INRA)
Source :
AJP-Endocrinology and Metabolism, AJP-Endocrinology and Metabolism, American Physiological Society, 2006, 291, pp.E372-E380. ⟨10.1152/ajpendo.00482.2005⟩, American Journal of Physiology. Endocrinology and Metabolism (291), E372-E380. (2006)
Publication Year :
2006
Publisher :
HAL CCSD, 2006.

Abstract

The function of adipocytes interspersed between myofiber fasciculi in skeletal muscle physiology and physiopathology is poorly documented. Because regional differences in adipocyte features have been reported in various species, we hypothesized that lipid metabolism and secretory function of intramuscular (IM) adipocytes differ from that of nonmuscular adipocytes. In the present study, adipocytes isolated from trapezius muscle were compared with subcutaneous and perirenal adipocytes in growing pigs. Between 80 and 210 days of age, gene expressions and/or activities of enzymes involved in lipogenesis or lipolysis were much lower ( P < 0.05) in adipocytes isolated from muscle than in those from other locations. Insulin-induced lipogenesis and lipolytic efficiency after catecholamine addition were also the lowest ( P < 0.05) in IM adipocytes. In these cells, the age-related increase (+300%) in the ratio of mRNA levels of fatty acid synthase to hormone-sensitive lipase paralleled the enlargement of adipocyte diameters (+70%, P < 0.05) and the increase in lipid content in muscle (+135%, P < 0.05) during growth. Expressions of genes coding for leptin, adiponectin, and IGF-I, as well as for various hormonal receptors, were lower ( P < 0.05) in IM adipocytes than in other adipocytes, whereas levels of TNF-α mRNA did not differ between sites. Interestingly, IGF-II mRNA levels were higher ( P < 0.05) in IM adipocytes than in other adipocytes. These data support the view that IM fat is not just an ectopic extension of other fat locations but displays specific biological features during growth.

Details

Language :
English
ISSN :
01931849 and 15221555
Database :
OpenAIRE
Journal :
AJP-Endocrinology and Metabolism, AJP-Endocrinology and Metabolism, American Physiological Society, 2006, 291, pp.E372-E380. ⟨10.1152/ajpendo.00482.2005⟩, American Journal of Physiology. Endocrinology and Metabolism (291), E372-E380. (2006)
Accession number :
edsair.doi.dedup.....2560672cebccc14e72c89cf484ffe72e