Prior exposure of macrophages to a low temperature enhances their cyclic AMP responses due to microtubule disruption

摘要: Abstract Prior exposure of intact macrophages to a low temperature (4 °C) resulted in tremendous increases their cAMP-generating responses prostaglandin (PG) E1, epinephrine, adenosine, forskolin, and cholera toxin. The extent the enhancement was dependent on site stimulation by these agents. effect cold (a) completely reversed reexposure cold-treated cells 37 °C; (b) mimicked antimicrotubule agents, colchicine vinblastine; (c) not further increased or vinblastine treatment; (d) efficiently antagonized D2O taxol, microtubule stabilizers. These results demonstrated that cAMP generation mediated through disruption. effects microtubule-disrupting agents hormone-induced refractoriness also studied. Macrophages stimulated at °C PGE1 became refractory subsequent PGE1, regardless whether had been, were subsequently, exposed 4 °C. In contrast, presence colchicine, pretreated with °C, responded rechallenge normally. suggested disassembly microtubules provides condition unfavorable for development receptor refractoriness, but never favors recovery therefrom.