Human serum albumin inhibits prostacyclin production by endothelial cells: the relation of the inhibitory activity to sulfhydryl groups in albumin.
Human serum inhibited calcium ionophore-induced production of prostacyclin by cultured bovine aortic endothelial cells. The inhibitory fraction was purified from serum by anion-exchange and Blue-Sepharose affinity chromatography. The molecular weight of the purified substance was 67k dalton as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. It was identified as human serum albumin by N-terminal amino acid sequence analysis. Human serum albumin was separated to two forms by high-performance liquid chromatography: mercaptalbumin (SH type) and nonmercaptalbumin (SS type). Both types of albumin inhibited the conversion of arachidonic acid to prostaglandin H2 in a dose-dependent manner without affecting phospholipase A2 or prostacyclin synthetase. This inhibition was more potent in mercaptalbumin than in nonmercaptalbumin. These results suggest that the conversion between mercaptalbumin and nonmercaptalbumin may play an important role in the modulation of prostacyclin synthesis by endothelial cells.
Murohara
Y
Y
Department of Internal Medicine, Faculty of Medicine, Kyoto University, Japan.
Yui
Y
Y
Hattori
R
R
Kadota
K
K
Kawai
C
C
D000244:Adenosine Diphosphate / Q000494:pharmacology; D000818:Animals; D001011:Aorta / Q000166:cytology / Q000378:metabolism; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000494:pharmacology; D001920:Bradykinin / Q000494:pharmacology; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D002417:Cattle; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism*; D011464:Epoprostenol / Q000096:biosynthesis*; D005110:Extracellular Space / Q000378:metabolism; D006801:Humans; D015759:Ionomycin / Q000494:pharmacology; D012709:Serum Albumin / Q000494:pharmacology*
D001095:Arachidonic Acids; D012709:Serum Albumin; C001702:mercaptoalbumin; D016718:Arachidonic Acid; D000001:Calcimycin; D015759:Ionomycin; D000244:Adenosine Diphosphate; D011464:Epoprostenol; D001920:Bradykinin; D002118:Calcium