Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01178 (oxytocin)
 15,767 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The distribution of [3H]oxytocin binding sites among various subcellular fractions of rat myometrium paralleled the distribution of 5'-nucleotidase, a plasma membrane marker enzyme, but not of NADPH-cytochrome c reductase or succinate-cytochrome c reductase, which are endoplasmic reticulum and mitochondrial marker enzymes respectively. [3H]Oxytocin binding to the most enriched plasma membrane fraction showed the degree of selectivity with respect to hormone analogues that is expected for the oxytocin receptor. The binding of oxytocin to this fraction showed an apparent Kd of 1.98 X 10(-9) M and a capacity of 1.28 pmol mg-1. It is concluded that the oxytocin receptor is located on the plasma membrane of the smooth muscle cells of the rat uterus.
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PMID:Localization of the oxytocin receptor in the plasma membrane of rat myometrium. 20 28

Direct binding of 125I-Tyr8-bradykinin to a microsomal fraction prepared from rat uterine smooth muscle, showed an apparent dissociation constant (KD) at 29 degrees C of 5.0 X 10(-10) M calculated from kinetic studies and 6.6 X 10(-10) M from Scatchard plot analysis. The binding of 125I-Tyr8-bradykinin was reversible and saturable, and demonstrated high specificity for Tyr8-bradykinin, bradykinin and Lys-bradykinin, but was not displaced by unrelated peptides angiotensin I, angiotensin II, Arg8-vasopressin and oxytocin. The binding sites were copurified by differential centrifugation and on a discontinuous sucrose density gradient with 5'-nucleotidase activity, a plasma membrane marker enzyme. Prolonged intravenous infusion of bradykinin (5 nmol/h for 2 days) induced a 20% decrease in the number of bradykinin binding sites without a change in the equilibrium dissociation constant. The present results demonstrate that receptors mediating the effect of bradykinin on rat uterine smooth muscle are situated on plasma membranes and the regulation of the receptors is in part under the control of endogenous bradykinin levels.
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PMID:Bradykinin receptors in rat uterine smooth muscle: studies using radiolabeled ligand binding. 615 Dec 67