[Glucocorticoid receptor (GCR) in canine peripheral lymphocyte during early postburn period]

In this report, using the radio-ligand binding assay with [3H]-dexamethasone (Dex) as the ligand, we studied the changes in glucocorticoid receptor (GCR) in canine peripheral lymphocyte under unstressed condition and during the early postburn period (within 48 hours after burn). The results showed that the apparent binding capacity (Ro) and the apparent dissociation constant (Kd) of GCR were 8468 +/- 993 sites per cell and 10.2 +/- 0.6 nM (n = 6), respectively, under unstressed condition. The number of [3H]-Dex specific binding sites measured by the single saturated analysis (Rs) from 16 healthy mongrel dogs under unstressed condition was 4531 +/- 396 sites per cell. The Rs was decreased sharply at the second post-burn hour, reaching the lowest level of 2501 +/- 460 sites per cell. But it recovered to 78.9% of the level measured in unstressed condition. There was significant negative relationship between the plasma cortisol concentration and GCR levels of lymphocyte. The results suggest that the changes in GCR in postburn period may be related to the down-regulation of GCR by Gc; that GCR may be of very important significance in the pathophysiologic changes after burn injury.