Figure 3. Dose-response relationships of muscarinic agonists on follicular responses.

A, F_in generated by ACh and oxotremorine in a single follicle. The ACh concentrations were 0.05, 0.1, 0.5, 1, 10 and 100 μm, and the oxotremorine concentrations were 1, 10 and 100 μm. B, inhibition by oxotremorine of I_K,cAMP (elicited by ADE). Oxotremorine (0.5 or 100 μm) was applied at the peak of the K⁺ current. C, preincubation with oxotremorine also blocked I_K,cAMP. The oxotremorine concentrations were 0.1, 1, 10, 100 and 1000 μm. Note that at intermediate concentrations (1-100 μm) I_K,cAMP inhibition was reversed rapidly on washout. D, carbachol (open symbols) and oxotremorine (filled symbols) dose-response relationships for F_in activation (circles) and I_K,cAMP inhibition (triangles). Mean of 9-13 follicles from 5 frogs.