Identification of 11,13-dihydroxy-14-octadecaenoic acid as a circulating Na+/K(+)-ATPase inhibitor.
Two digitalis-like compounds (DLC) were purified to homogeneity from bovine plasma. The purification procedure consisted of organic extractions and batch chromatography followed by three subsequent separations using reverse-phase high-performance liquid chromatography. The presence of a DLC in the different fractions was monitored by their ability to inhibit (a) [3H]ouabain binding to rat brain synaptosomes, and (b) microsomal Na+/K(+)-ATPase activity. Using mass spectrometry and nuclear magnetic resonance spectroscopy the structure of one of the DLCs was identified as 11,13-dihydroxy-14-octadecaenoic acid. It is suggested that this new hydroxy, unsaturated, fatty acid derivative may regulate Na+/K(+)-ATPase activity under some physiological and pathological conditions.
Lichtstein
D
D
Department of Physiology, Hebrew University-Hadassah Medical School, Jerusalem, Israel.
Samuelov
S
S
Gati
I
I
Felix
A M
AM
Gabriel
T F
TF
Deutsch
J
J
D000818:Animals; D001921:Brain / Q000378:metabolism; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008861:Microsomes / Q000187:drug effects / Q000201:enzymology; D009829:Oleic Acids / Q000097:blood* / Q000737:chemistry; D010042:Ouabain / Q000378:metabolism; D011485:Protein Binding / Q000187:drug effects; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors*
D009829:Oleic Acids; C067685:11,13-dihydroxy-14-octadecaenoic acid; D010042:Ouabain; D000254:Sodium-Potassium-Exchanging ATPase