title: Measurement of [Ca²+]i in smooth muscle strips using front-surface fluorimetry.
abstract: In regulating the contraction of smooth muscle cells, changes in the cytosolic concentrations of Ca(2+) ([Ca(2+)](i)) play a primary role as the initiation of contraction is associated with Ca(2+) binding to calmodulin with the subsequent activation of myosin light chain kinase. During the contraction induced by receptor-mediated stimulation, however, there are temporal changes in the relationship between [Ca(2+)](i) and the developed tension. Furthermore, the receptor-mediated stimulation also produces a proportionately greater tension for a given change in [Ca(2+)](i) than does K(+) depolarization. Therefore, it is important to measure [Ca(2+)](i) and tension simultaneously in order to determine the molecular and cellular mechanisms in both the regulation of contraction and relaxation of smooth muscle. For this purpose, front-surface fluorimetry of fura-2, a [Ca(2+)](i) indicator dye, has been performed on small smooth muscle strips.
authors.affiliation: Division of Molecular Cardiology, Research Institute of Angiocardiology, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
authors.forename: Hideo
authors.initials: H
authors.lastname: Kanaide
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002417:Cattle; D005470:Fluorometry / Q000379:methods*; D016257:Fura-2 / Q000031:analogs & derivatives* / Q000378:metabolism; D006168:Guinea Pigs; D006801:Humans; D009119:Muscle Contraction / Q000502:physiology*; D009130:Muscle, Smooth / Q000378:metabolism*; D011817:Rabbits; D051381:Rats
chemical_list: C049925:fura-2-am; D002118:Calcium; D016257:Fura-2