Inorganic phosphate promotes relaxation of chemically skinned smooth muscle of guinea-pig Taenia coli
Schneider, M.; Sparrow, M.; Rüegg, J.C.
Experientia 37(9): 980-982
1981
ISSN/ISBN: 0014-4754 PMID: 7297662 Document Number: 177579
In the presence of calmodulin and phosphate and an ATP-regenerating system, Triton-treated skinned fibers of the tenia coli could be made to contract and relax by step changes of Ca2+ within .apprx. 30 s. In the absence of phosphate, relaxation was slower. During this slow relaxation, tension was not maintained actively. The passive tension could be abolished by phosphate (3-6 mM). Phosphate had little effect on contractile tension but decreased the speed of contraction.