Increased concentrations of nonesterified arachidonic acid, 12L-hydroxy-5,8,10,14-eicosatetraenoic acid, prostaglandin E2, and prostaglandin F2alpha in epidermis of psoriasis

Abstract

Lesional epidermis of psoriasis has a probable reduction in the cyclic AMP/cyclic GMP ratio. This altered ratio may in part be responsible for the characteristic glycogen storage, rapid cell proliferation, and reduced differentiation in lesional epidermis. The concentrations of prostaglandins E2 and F2alpha, free arachidonic acid, and 12L-hydroxy-5,8,10,14-eicosatetrawnoic acid in specimens of uninvolved and involved epidermis of psoriasis were measured with deuterium-labeled carriers and multiple ion analysis. Snap frozen specimens contained: 1.4 +/- 0.4 mug/g (wet weight) of arachidonic acid in uninvolved in contrast to 36.3 +/- 16.7 mug/g in involved epidermis (P = 0.015); less than 0.05 +/- 0.01 mug/g of hydroxyeicosatetraenoic acid in uninvolved in contrast to 4.1 +/- 1.9 mug/g in involved epidermis (P = 0.015); 23.6 +/- 5.0 ng/g of prostaglandin E2 in uninvolved in contrast to 33.1 +/- 5.7 ng/g in involved epidermis (P less than 0.01); and 21.0 +/- 4.4 ng/g of prostaglandin F2alpha in uninvolved in contrast to 39.0 +/- 5.9 ng/g in involved epidermis (P less than 0.01). The arachidonic acid and hydroxyeicosatetraenoic acid levels in involved epidermis were strongly correlated (r = 0.97). The increased levels of arachidonic acid and 12L-hydroxy-5,8,10,14-eicosatetraenoic acid in involved epidermis may have diagnostic and pathophysiological importance.