title: Ca2+ release by inositol trisphosphate from Ca2+-transporting microsomes derived from uterine sarcoplasmic reticulum.
abstract: Microsomes derived from pregnant uterine sarcoplasmic reticulum, isolated by differential and sucrose density gradient centrifugation, accumulates Ca2+ in the presence of ATP. Inositol trisphosphate caused release of this Ca2+, in a dose dependent manner. 40% of the Ca2+ that can be released by the ionophore A23187 was released by 5 microM inositol trisphosphate. Removal of Mg by EDTA prior to addition of inositol trisphosphate did not change the course of Ca2+ release. These results indicate that by mobilizing intracellular Ca2+, inositol trisphosphate may be the link between hormonal stimuli and smooth muscle contraction.
mesh_terms: D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D002417:Cattle; D002458:Cell Fractionation; D002499:Centrifugation, Density Gradient; D005260:Female; D015544:Inositol 1,4,5-Trisphosphate; D007295:Inositol Phosphates / Q000378:metabolism*; D007700:Kinetics; D008861:Microsomes / Q000378:metabolism* / Q000648:ultrastructure; D011247:Pregnancy; D011270:Pregnancy, Animal; D012519:Sarcoplasmic Reticulum / Q000378:metabolism* / Q000648:ultrastructure; D013403:Sugar Phosphates / Q000378:metabolism*; D014599:Uterus / Q000378:metabolism*
chemical_list: D007295:Inositol Phosphates; D013403:Sugar Phosphates; D000001:Calcimycin; D015544:Inositol 1,4,5-Trisphosphate; D002118:Calcium