11-glutathionylhepoxilin-a3 and Insulinoma

11-glutathionylhepoxilin-a3 has been researched along with Insulinoma* in 1 studies

Other Studies

1 other study(ies) available for 11-glutathionylhepoxilin-a3 and Insulinoma

Article	Year
Biosynthesis of hepoxilins: evidence for the presence of a hepoxilin synthase activity in rat insulinoma cells. FEBS letters, 2003, Mar-13, Volume: 538, Issue:1-3 The 12(S)-lipoxygenase (12-LOX) pathway of arachidonic acid (AA) metabolism after dioxygenation to 12(S)-hydroperoxy-eicosatetraenoic acid is bifurcated in a reduction route to formation of 12(S)-hydroxy-eicosatetraenoic acid (12-HpETE) and an isomerization route to formation of hepoxilins. Interestingly, we found that the rat insulinoma RINm5F cells, which are devoid of cytoplasmic glutathione peroxidase (cGPx)/phospholipid hydroperoxide glutathione peroxidase (PHGPx), produce solely hepoxilin A(3) (HXA(3)). Since HXA(3) synthesis was abolished in heat-denatured or cGPx- or PHGPx-transfected cells, it was tempting to speculate that a HXA(3) synthase activity regulated by cGPx/PHGPx is present. To confirm this assumption we incubated AA with HeLa cells overexpressing the rat leukocyte-type 12-LOX. Neither HXA(3) nor 12(S)-HETE were detected due to abundance of cGPx/PHGPx. But, pretreatment of transfected cells with diethyl maleate, an inhibitor of glutathione and PHGPx, restored HXA(3) synthase and 12-LOX activities. Thus, we conclude, that cells containing rat leukocyte-type 12-LOX also possess an intrinsic HXA(3) synthase activity, which is activated by inhibition of cGPx/PHGPx. In normal cells HXA(3) is down-regulated by cGPx/PHGPx, but, it is persistently activated in oxidatively stressed cells deficient in cGPx/PHGPx, such as RINm5F. Topics: 8,11,14-Eicosatrienoic Acid; Animals; Arachidonate 12-Lipoxygenase; Chromatography, High Pressure Liquid; Gas Chromatography-Mass Spectrometry; Glutathione Peroxidase; Humans; Insulinoma; Intramolecular Oxidoreductases; Rats; Tumor Cells, Cultured	2003

Article

Year

Biosynthesis of hepoxilins: evidence for the presence of a hepoxilin synthase activity in rat insulinoma cells.

FEBS letters, 2003, Mar-13, Volume: 538, Issue:1-3

The 12(S)-lipoxygenase (12-LOX) pathway of arachidonic acid (AA) metabolism after dioxygenation to 12(S)-hydroperoxy-eicosatetraenoic acid is bifurcated in a reduction route to formation of 12(S)-hydroxy-eicosatetraenoic acid (12-HpETE) and an isomerization route to formation of hepoxilins. Interestingly, we found that the rat insulinoma RINm5F cells, which are devoid of cytoplasmic glutathione peroxidase (cGPx)/phospholipid hydroperoxide glutathione peroxidase (PHGPx), produce solely hepoxilin A(3) (HXA(3)). Since HXA(3) synthesis was abolished in heat-denatured or cGPx- or PHGPx-transfected cells, it was tempting to speculate that a HXA(3) synthase activity regulated by cGPx/PHGPx is present. To confirm this assumption we incubated AA with HeLa cells overexpressing the rat leukocyte-type 12-LOX. Neither HXA(3) nor 12(S)-HETE were detected due to abundance of cGPx/PHGPx. But, pretreatment of transfected cells with diethyl maleate, an inhibitor of glutathione and PHGPx, restored HXA(3) synthase and 12-LOX activities. Thus, we conclude, that cells containing rat leukocyte-type 12-LOX also possess an intrinsic HXA(3) synthase activity, which is activated by inhibition of cGPx/PHGPx. In normal cells HXA(3) is down-regulated by cGPx/PHGPx, but, it is persistently activated in oxidatively stressed cells deficient in cGPx/PHGPx, such as RINm5F.

Topics: 8,11,14-Eicosatrienoic Acid; Animals; Arachidonate 12-Lipoxygenase; Chromatography, High Pressure Liquid; Gas Chromatography-Mass Spectrometry; Glutathione Peroxidase; Humans; Insulinoma; Intramolecular Oxidoreductases; Rats; Tumor Cells, Cultured

2003