Identification of 12(S)-hydroxyeicosatetraenoic acid in the young rat lens.
Evidence is presented indicating that young rat lens has the capacity to synthesize 12(S)-hydroxyeicosatetraenoic acid (12(S)-HETE) from exogenous arachidonic acid (AA). A 9,000 xg supernatant prepared from 15 day old rat lenses, when incubated with calcium and U-[14C]-AA, generated a radiolabelled product with a retention time identical to authentic unlabelled 12-HETE in two different HPLC solvent systems. Mass spectral analysis provided evidence that the metabolite was 12-HETE while chiral studies demonstrated the exclusive presence of the 12(S) isomer. Radiolabelled 12-HETE synthesis was inhibited by preincubating the 15 day old rat lens supernatant with 0.2 Mm curcumin, a mixed cyclooxygenase/lipoxygenase inhibitor. Radiolabelled 12(S)-HETE synthetic capacity was highest in the 4 day old rat lens, the earliest time period measured, and rapidly declined with age reaching negligible levels at about 4 months. These results suggest that the young rat lens possess the biosynthetic capacity to generate radiolabelled 12(S)-HETE from U-[14]C-AA. The profile of 12-HETE synthetic activity suggests a possible regulatory function of the hydroxylated AA metabolite in the developing lens.
Lysz
T W
TW
Department of Surgery, UMDNJ-New Jersey Medical School, Newark 07103.
Wu
Y
Y
Brash
A
A
Keeting
P E
PE
Lin
C
C
Fu
S C
SC
D019377:12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; D000818:Animals; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000378:metabolism; D002122:Calcium Chloride / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid; D003474:Curcumin / Q000494:pharmacology; D006893:Hydroxyeicosatetraenoic Acids / Q000037:antagonists & inhibitors / Q000096:biosynthesis*; D007536:Isomerism; D007908:Lens, Crystalline / Q000378:metabolism*; D013058:Mass Spectrometry; D051381:Rats; D011919:Rats, Inbred Strains
D001095:Arachidonic Acids; D006893:Hydroxyeicosatetraenoic Acids; D016718:Arachidonic Acid; D019377:12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; D003474:Curcumin; D002122:Calcium Chloride