Effect of low and high methional concentrations on prostaglandin biosynthesis in microsomes from bovine and sheep vesicular glands.

The effect of methional on prostaglandin biosynthesis from 5,8,11,14-eicosatetraenoic acid was studied with microsomes from both bovine vesicular glands (BVG) and sheep vesicular glands (SVG). Ethylene was identified when methional was added to the fatty acid-microsome incubation systems showing that oxygen centered radicals such as hydroxyl radical were generated during incubation. A low methional level, 1 mM, enhanced the rate of prostaglandin biosynthesis in both BVG and SVG. A high methional level, 10 mM, inhibited prostaglandin biosynthesis in both BVG alone and SVG solubilized with 1% Tween 20. The inhibitory effect of 10 mM methional was reversed by lyophilization. These data suggest that oxygen centered radicals are used in prostaglandin biosynthesis even though they inactivate the enzyme complex.