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Giovanni De Pergola, Xuefan Xu, Björn Carlsson, Peter Eriksson, Staffan Edén, Riccardo Giorgino, Per Björntorp, Estradiol regulation of mRNA expression of stimulatory G-protein α-subunit in white adipose tissue from female rats, Acta Endocrinologica, Volume 130, Issue 2, Feb 1994, Pages 146–150, https://doi.org/10.1530/eje.0.1300146
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Abstract
De Pergola G, Xu X, Carlsson B, Eriksson P, Edén S, Giorgino R, Björntorp P. Estradiol regulation of mRNA expression of stimulatory α-subunit in white adipose tissue from female rats. Eur J Endocrinol 1994;130:146–50. ISSN 0804–4643
Adipose tissue has been recognized as a major peripheral metabolic target of estrogens. The present study was addressed to examine in female rats whether differences in the adipose tissue mRNA expression of α-subunit of stimulatory (Gs) and/or inhibitory (Gj) G-proteins exist between intact and ovariectomized rats, the latter with or without estradiol or testosterone treatment. The fat cell membrane protein amount of Gs and Gj α-subunit also was examined. All these parameters were evaluated in parametrial fat tissue samples obtained from 40 female Sprague-Dawley rats. A group of rats (N=20) was investigated for evaluation of mRNA expression and another group (N=20) for quantification of the protein amount of Gs and Gj α-subunit. Each group was represented by five control rats (sham-operated), five ovariectomized (OVX) rats, five ovariectomized rats treated with estradiol (OVXE) and five ovariectomized rats treated with testosterone (OVXT). Ribonucleic acid extracted from adipose tissue and analyzed by northern blot with Gαs, Gαi-1 and Gαi-2 cRNA probes revealed three major bands with estimated sizes of 1.9, 3.5 and 2.35 kb, respectively. Messenger RNA quantitative analysis, by a solution of hybridization RNAase protection assay on total nucleic acid samples, showed that the amount of Gαi-1 and Gαi-2 mRNA was similar within the different groups, whereas the Gαs mRNA was significantly less abundant (p <0.01) in OVX and OVXT rats than in control or OVXE rats. No difference in Gαs mRNA content was found between control and OVXE rats. As with mRNA analysis, protein quantitative analysis by an enzyme-linked immunosorbent assay in fat cell membrane preparation showed that the amount of Gαi(1–2) was similar within the different groups and that the Gαs content was significantly higher in control and OVXE rats than in OVX and OVXT rats (p<0.01). This study in female rats shows that estradiol may be involved in the control of protein amount and mRNA expression of Gs α-subunit in adipose tissue. These results may explain in part how estrogens regulate the variations of body fat mass in female rats.
