Figure 6
The effect of 3-15 days of incubation with muscarinic agonists ACh and CCh on ASMC responsiveness. A. Cell responsiveness to ACh (10-3 M) or CCh (10-5 M) in the presence or absence of atropine (10-6 M). B-D. ACh (10-3 M) and CCh (10-5 M)-induced contractions of rabbit tracheal smooth muscle cells cultured as indicated in serum free medium (control), medium containing 10% FBS, ACh (10-5 M) or CCh (3 × 10-7 M) for 3 (B), 7 (C) or 15 (D) days. Cell responsiveness to ACh or CCh was estimated as a percentage of the area of cell measured 5 min after the addition of ACh or CCh in cell medium to the initial area before the addition of muscarinic agonist. *P < 0.05 and **P < 0.01 compared with the respective control.