[Changes in glucocorticoid receptor and phospholipase A2 in guinea pig asthma models]

In this study we determined the glucocorticoid receptor (GR) level (using 3H-dexamethasone as a ligand) and phospholipase A2 (PLA2) activity of lung tissue in guinea pig asthma models at 1st, 3rd, 7th and 14th day of asthma attacks. The results showed that the GR maximal binding capacity (Bmax, fmol/mg pro.) were 54.36 +/- 26.57, 30.99 +/- 10.01, 19.40 +/- 10.06, and 29.16 +/- 11.35; GR dissociation constant (Kd, nmol/L) were 12.73 +/- 4.06, 8.28 +/- 3.23, 5.70 +/- 2.91, and 6.40 +/- 2.64 respectively; and PLA2 actisis (U) were 181.58 +/- 41.50, 239.80 +/- 61.15, 243.08 +/- 31.35, and 235.71 +/- 86.13 respectively. The GR Bmax, Kd and PLA2 of actisis control group were 61.48 +/- 27.60 (fmol/mg pro.), 13.11 +/- 2.88 (nmol/L), 81.06 +/- 15.97 (U). The GR Bmax and Kd of asthmatic animals decreased significantly since the 3rd day, but the PLA2 activity increased significantly since the 1st day as compared to the control group (P < 0.01). The changes of GR Bmax had significant negative correlation with those of the PLA2 activity (r = -0.9023, P < 0.05). The mechanism of the GR and PLA2 actisis changes of asthma animal models were discussed.