Corticosterone binding in myocardial tissue of rats after chronic stress and adrenalectomy.
Male rats were trained to swim for 9-10 days to assess the effect of chronic stress on the capacity and affinity of specific glucocorticoid binding in the cytosol fraction of myocardial tissue. A significant decrease in the binding capacity for corticosterone (Cpd B) was found 24 hours after the last swimming test, while the affinity constant remained unchanged. Contrary to Cpd B binding, there was no change in the capacity of dexamethasone binding, and there was no decrease in the Cpd B binding capacity in rats which had been adrenalectomized 2 days prior to the training period. We conclude that daily swimming for 9-10 days alters the numbers of cytoplasmic Cpd B binding sites in the face of increased adrenocortical activity, while not affecting dexamethasone binding in the cytosol fraction of myocardial tissue.
D000315:Adrenalectomy; D000818:Animals; D003345:Corticosterone / Q000378:metabolism*; D003600:Cytosol / Q000378:metabolism; D003907:Dexamethasone / Q000378:metabolism; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D010805:Physical Conditioning, Animal; D005082:Physical Exertion; D051381:Rats; D011919:Rats, Inbred Strains; D011965:Receptors, Glucocorticoid / Q000378:metabolism; D013550:Swimming
D011965:Receptors, Glucocorticoid; D003907:Dexamethasone; D003345:Corticosterone