title: Differential regulation of Paramecium ciliary motility by cAMP and cGMP.
abstract: cAMP and cGMP had distinct effects on the regulation of ciliary motility in Paramecium. Using detergent-permeabilized cells reactivated to swim with MgATP, we observed effects of cyclic nucleotides and interactions with Ca2+ on the swimming speed and direction of reactivated cells. Both cAMP and cGMP increased forward swimming speed two- to threefold with similar half-maximal concentrations near 0.5 microM. The two cyclic nucleotides, however, had different effects in antagonism with the Ca2+ response of backward swimming and on the handedness of the helical swimming paths of reactivated cells. These results suggest that cAMP and cGMP differentially regulate the direction of the ciliary power stroke.
authors.affiliation: Department of Biochemistry and Neurosciences Training Program, College of Agricultural and Life Sciences, University of Wisconsin, Madison 53706.
authors.forename: N M
authors.initials: NM
authors.lastname: Bonini
authors.forename: D L
authors.initials: DL
authors.lastname: Nelson
mesh_terms: D000818:Animals; D002118:Calcium / Q000502:physiology; D002465:Cell Movement / Q000187:drug effects; D002923:Cilia / Q000187:drug effects / Q000502:physiology*; D000242:Cyclic AMP / Q000494:pharmacology*; D006152:Cyclic GMP / Q000494:pharmacology*; D008954:Models, Biological; D010247:Paramecium / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure
chemical_list: D000242:Cyclic AMP; D006152:Cyclic GMP; D002118:Calcium