Glucocorticoid Receptor And Beta-adrenoceptor Expression In Epididymal Adipose Tissue From Stressed Rats

Adipocytes isolated from epididymal adipose tissue of foot-shock stressed rats are supersensitive to isoprenaline and subsensitive to norepinephrine. These alterations are probably mediated by a stress-induced increase in plasma corticosterone levels. We investigated whether foot-shock stress modifies the expression of glucocorticoid receptors (GRs) and β-adrenergic protein receptors (β-ARs) in epididymal adipose tissue from rats submitted to one daily foot-shock session on three consecutive days. This stress protocol caused decreases in GR, β1-AR, and β3-AR protein levels, but caused an increase in β2-AR. These results confirm and support previous functional studies. The alterations in protein expression may be modulated by the high corticosterone levels that downregulate the glucocorticoid receptor.1018328332Langin, D., Coexistence of three beta-adrenergic receptor subtypes in white fat cells of various mammalian species (1991) Eur. J. Pharmacol., 199, pp. 291-301Farias-Silva, E., Stress-induced alteration in the lipolytic response to beta-adrenoceptor agonists in rat white adipocytes (1999) J. Lipid Res., 40, pp. 1719-1727Vanderlei, L.C.M., Influence of the estrous cycle on the sensitivity to catecholamines in rat atria from rats submitted to foot-shock stress (1996) Can. J. Physiol. Pharmacol., 74, pp. 670-678Marcondes, F.K., Stress-induced subsensitivity to catecholamines depends on the estrous-cycle (1996) Can. J. Physiol. Pharmacol., 74, pp. 7-13Kant, G.J., Effects of chronic stress on plasma corticosterone (1987) Physiol. Behav., 40, pp. 775-779Laemmli, U.K., Cleavage of structural proteins during the assembly of head of bacteriophage T4 (1970) Nature, 227, pp. 680-685Nourani, F.R.R., Spadari, R.C., De Moraes, S., Foot-shock stress-induced supersensitivity to isoprenaline in the isolated pacemaker of the rat: Effects of the compounds RU-38486 and RU-28362 (1992) Gen. Pharmacol., 23, pp. 787-791Evans, B.A., Differential regulation of β3-adrenoceptors in gut and adipose tissue of genetically obese (ob/ob) C57BL/6J (1998) Br. J. Pharmacol., 124, pp. 763-771Bakipanos, E., Silva, J.E., Opposing effects of glucocorticoids on β3-adrenergic receptor expression in HIB-1B brown adipocytes (2002) Mol. Cell. Endocrinol., 190, pp. 29-37Collins, S., A cAMP response element in the β2-adrenergic receptor gene confers transcriptional autoregulation by cAMP (1990) J. Biol. Chem., 265, pp. 19330-19335Deak, T., Long-term changes in mineralocorticoid and glucocorticoid receptor occupancy following exposure to an acute stressor (1999) Brain Res., 847, pp. 211-220McEwen, B.S., Gould, E.A., Sakai, R.R., The vulnerability of the hippocampus to protective and destructive effects of glucocorticoids in relation to stress (1992) Br. J. Psych., 2 (SUPPL.), pp. 18-23Scribner, K.A., Chronic streptozotocin diabetes in rats facilitates the acute stress response without altering pituitary or adrenal responsiveness to secretagogues (1991) Endocrinology, 120, pp. 99-108Al-Mohaisen, M., Cardounel, A., Kalimi, M., Repeated immobilization stress increases total cytosolic glucocorticoid receptor in rat liver (2000) Steroids, 65, pp. 8-15Alexandrova, M., Farkas, P., Stress-induced changes of glucocorticoid receptor in rat liver (1992) J. Steroid Biochem. Mol. Biol., 42, pp. 493-498Verago, J.L., Grassi-Kassisse, D.M., Spadari-Bratfisch, R.C., Metabolic markers following beta-adrenoceptor agonist infusion in foot-shock stressed rats (2001) Braz. J. Med. Biol. Res., 34, pp. 1197-1207Farias-Silva, E., Subsensitivity to insulin in adipocytes from rats submitted to foot-shock stress (2002) Can. J. Physiol. Pharmacol., 80, pp. 783-78