Leukotriene C4 ([3H]-LTC4) binding to membranes isolated from a hamster smooth muscle cell line (DDT1MF2).
Leukotriene C4 (LTC4) has been demonstrated to induce contraction of the smooth muscle cell line DDT1MF2. A partially purified membrane fraction obtained from these cells exhibited a high affinity binding site for LTC4. Binding of [3H]-LTC4 was saturable, specific and reversible with a dissociation constant (Kd) of 21 +/- 4 nM. The maximum number of binding sites (Bmax) was 55 +/- 5 pmol/mg of protein. Specificity was demonstrated in competition studies in which the Ki of LTC4 against specifically bound [3H]-LTC4 was 12 nM whereas Leukotriene D4 (LTD4) and Leukotriene E4 (LTE4) had a Ki of 38 +/- 4 and 4.7 +/- 0.5 nM respectively. A previously described antagonist of leukotriene-induced smooth muscle contraction PFL 55712 had a Ki of 23 +/- 2 nM as determined by competition binding experiments.
D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D006224:Cricetinae; D007700:Kinetics; D007890:Leiomyosarcoma; D009130:Muscle, Smooth / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000378:metabolism*; D018077:Receptors, Leukotriene; D013189:SRS-A / Q000378:metabolism*
D011956:Receptors, Cell Surface; D018077:Receptors, Leukotriene; D013189:SRS-A