| Abstract: | With the radioligand binding assay, the maximal binding capacity (Bmax) and affinity (Kd) of alpha, beta-adrenoceptors(alpha AR,beta AR) in the lung membrane and glucocorticoid receptor (GCR) in the lung cytoplasma of rats with experimental respiratory distress syndrome (RDS) induced by oleic acid have been measured. The results demonstrated that the content of alpha AR in rat lungs increased continuously during the experiment, the Bmax at 1st, 4th and 6th hour after oleic acid injection were 139 +/- 40, 127 +/- 12, 116 +/- 25 fmol/mg protein, significantly higher than normal value (83 +/- 7, n = 8-10, P < 0.01). Meanwhile, the content of beta AR and GCR decreased continuously, the Bmax at the same time were 364 +/- 18, 307 +/- 55, 240 +/- 66 and 146 +/- 28, 153 +/- 37, 150 +/- 32 fmol/mg protein respectively, significantly lower than their normal value (490 +/- 61, 227 +/- 14 fmol/mg protein, n = 6-10, P < 0.01). The results indicate that the changes of these receptors may be of significance in the pathogenesis of ARDS. |
