Circadian variation of cytosol glucocorticoid receptors in human polymorphonuclear leukocytes (PMN) and mononuclear cells (MN) in a normal population.
Glucocorticoid cytosol and whole cell receptors from human PMN's have been quantified, and compared to those of human MN leukocytes on the same blood sample. The normal cytosol PMN receptor density (N = 15) averaged 1,254 +/- 105 (SE) molecules bound/cell at 0900 h and increased significantly to 1,497 +/- 98 at 2,100 h (P less than 0.02). MN cell cytosol receptor density was 1,198 +/- 145 at 0900 h and increased significantly to 1,551 +/- 117 molecules bound/cell at 2,100 h (P less than 0.01). Corresponding whole cell receptor densities at 0900 h were 2,845 +/- 273 (PMN) and 3,547 +/- 290 (MN) and these did not change significantly at 2,100 h.


CONCLUSIONS
Cytosol receptors in normal human PMN and MN cells increased significantly at 2,100 h from the 0900 h level while serum cortisol levels were dropping. Whole cell receptors in the same PMN and MN cell samples did not change significantly between 0900 and 2,100 h. The normal circadian variation in serum cortisol influences the distribution of the glucocorticoid receptor between the cytosol and the nucleus, but does not influence the amount of receptor available to the whole cell. This is the first time that an endogenous physiological variation of cortisol concentration has been utilized to demonstrate a corresponding change in receptor capacity in vivo.
D002940:Circadian Rhythm; D003600:Cytosol / Q000378:metabolism; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D009000:Monocytes / Q000378:metabolism*; D009504:Neutrophils / Q000378:metabolism*; D011965:Receptors, Glucocorticoid / Q000378:metabolism*
D011965:Receptors, Glucocorticoid; D006854:Hydrocortisone