Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01185 (vasopressin)
 23,126 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A high affinity Ca2+-stimulated, Mg2+-dependent ATPase (Ca2+-Mg2+-ATPase) was identified in microsomes and plasma membrane vesicles isolated from rat hepatocytes. The distribution of this enzyme was similar to that of the plasma membrane marker enzymes alkaline phosphodiesterase and 5'-nucleotidase. The Ca2+-Mg2+-ATPase had an apparent half-saturation constant of approximately 75 nM for Ca2+. After incubation of rat hepatocytes with 25 nM vasopressin for 3 min, the activity of Ca2+-Mg2+-ATPase was decreased 15-30%. The effect of vasopressin on the activity of this enzyme was near maximal after incubating hepatocytes with vasopressin for only 15 sec. The concentration of vasopressin needed for half-maximal inhibition of this enzyme in hepatocytes was approximately 6 nM. Treatment of the hepatocytes with 10 microM phenylephrine caused about a 10% decrease in ATPase activity while 10 nM glucagon or 200 microU/ml insulin did not affect the enzyme. These findings suggest that inhibition of the Ca2+-Mg2+-ATPase activity may be part of the mechanism by which vasopressin and alpha-adrenergic agonists elevate cytosolic Ca2+ in hepatocytes.
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PMID:Regulation of Ca2+-Mg2+-ATPase activity in hepatocyte plasma membranes by vasopressin and phenylephrine. 613 76

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

It was shown that kallikreinogen content was decreased in blood of old rabbits, kallikrein activity was somewhat increased, kininase activity was significantly decreased. In old animals, adenosine metabolism was activated, this being evident from the rise of 5'-nucleotidase and adenosine deaminase activity in blood and myocardium. Hypothalamic stimulation resulted in significant activation of the kallikrein-kinin system and sharp increase of kallikrein activity, the shifts being less marked in old animals than in adults. In adult animals, vasopressin administration elicited more marked activation of the kallikrein-kinin and adenosine metabolism systems.
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PMID:Kallikrein-kinin system and adenosine metabolism system of blood and heart and their changes at hypothalamic-hypophyseal stimulation in rabbits of different age. 624 32