Figure 7.
Effects of glucocorticoid and PLC inhibitors on formoterol-induced upregulation of the expression of M3R. Rat ASMCs were randomly divided into five groups and treated as follows: 10−5 mmol/l formoterol for 1 or 24 h; 10−5 mmol/l formoterol for 24 h in the presence of 10−4 mmol/l BUD (glucocorticoid, BUD+F) or 10−5 mmol/l U73,122 (PLC inhibitor) or untreated. The expression levels of M3R, PLCβ1 and IP3 in the different treatment groups and the control were determined following a 15 min acetylcholine (10−4 mmol/l) stimulation. The protein levels of (A and B) M3R and (C and D) PLCβ1 in rat ASMCs were determined by western blot analysis and were determined by densitometry. The band densities were normalized to the β-actin control. (E) Expression of IP3 was determined by ELISA. The data are expressed as the mean ± standard deviation from three independent experiments. Δ P<0.05, compared with the 24 h formoterol only group. F1h, 1 h formoterol treatment; F24h, 24 h formoterol treatment; Con, control; IP3, inositol 1,4,5-trisphosphate; M3R, muscarinic M3 receptor, PLC, phospholipase C; BUD, budesonide; U, U73,122.