Electron microscopic demonstration of glucocorticoid recognition sites on isolated rat hepatocytes.
Ultrastructural evidence is presented for the presence of membrane-bound glucocorticoid recognition and binding sites. Corticosterone was derivatized at 3 different positions and coupled covalently to bovine serum albumin (BSA). All three derivatives competed for binding of [3H]corticosterone by isolated rat hepatocytes. The most effective competitor, corticosterone-succinate-BSA (CSB), was adsorbed onto colloidal gold particles (CSB-gold, 17 +/- 3 nm dia). When isolated rat hepatocytes or mouse pituitary tumor cells (AtT 20) are incubated with CSB-gold, specific binding in the microvilli-rich region of these cells is seen. This binding of CSB-gold is reduced by about 50% in the presence of unlabelled CSB or corticosterone.
Spindler
K D
KD
Institute of Zoology, Heinrich-Heine-University of Düsseldorf, Fed. Rep. Germany.
Krahwinkel
R
R
Kolb-Bachofen
V
V
Schlepper-Schäfer
J
J
D000818:Animals; D003345:Corticosterone / Q000378:metabolism; D066298:In Vitro Techniques; D008099:Liver / Q000737:chemistry* / Q000648:ultrastructure; D008297:Male; D016253:Microscopy, Immunoelectron; D051381:Rats; D011919:Rats, Inbred Strains; D011965:Receptors, Glucocorticoid / Q000032:analysis* / Q000648:ultrastructure; D013379:Substrate Specificity
D011965:Receptors, Glucocorticoid; D003345:Corticosterone