Figure 4: Carbachol inhibition of Isc is mediated by muscarinic receptors.
From: Inhibition of airway surface fluid absorption by cholinergic stimulation
(A) Carbachol (100 μM) inhibition of Isc in sheep trachea recovered slowly after washout (top Isc trace) and after application of atropine (Atrp, 10 μM, basolateral, bottom Isc trace). Inhibition could be repeated (top Isc trace). (B) Dose-dependent block of cholinergic effects on Isc by atropine. Sheep tracheas treated with 1 or 10 μM atropine prior to 1 to 100 μM carbachol. Both the initial increase and the later decrease in Isc are blocked. Atropine block was observed in 6 experiments with sheep (n = 3) and pigs (n = 2, Supplementary Figure 2A).
