Cholinoceptor Activation Subserving the Effects of Interferon Gamma on the Contractility of Rat Ileum

[摘要] Recombinant rat interferon γ stimulated the contractility ofisolated rat ileum at doses of 4–12 units/ml. Muscariniccholinoceptors were involved, as treatment of the tissue withatropine prevented the contractile response of the ileum.Furthermore, interferon γ increased the affinity of carbachol forthe cholinoceptors and did not change its maximum effect. Neurogenicpathways were also involved since pretreatment of ileum withhexamethonium, hemicholinium or tetrodotoxin impaired thecontractile effect of interferon γ. In contrast to the action ofexogenous carbachol, the effects of interferon γ are indirect. Theyappear to involve a G protein regulating phosphoinositide turnoverand cytoskeletal structures since they could not be induced in ileumstrips that were pretreated with pertussis toxin, phospholipase Cinhibitors (2-nitro-carboxyphenyl,NN-diphenyl carbamate andneomycin), cytochalasine B or colchicine.

[学科分类] 生理学与病理学