The effects of vitamin E depletion and repletion on prostaglandin dehydrogenase activity in tissues of young rabbits.

The key enzyme controlling prostaglandin (PG) catabolism, 15-hydroxyprostaglandin dehydrogenase (PGDH), was characterized in rabbit tissues. The apparent Michaelis constant (Km) using PGE2 as substrate was found to be 5.3, 4.0, 4.0 and 7.1 microM for semitendinosus and soleus muscles, heart and kidney, respectively. The effect of dietary vitamin E depletion and repletion on the PGDH activity in these tissues was studied. Vitamin E deficiency caused an elevation of PGDH activity in rabbit skeletal muscles but not in the heart and kidney. Oral supplementation of tocopherol acetate to the deficient animals did not affect the skeletal muscle PGDH activity. A long period of refeeding (30 days) was required to suppress the elevated PGDH level to the control values. The data indicates a higher turnover of the PGs in the vitamin E-deficient rabbit skeletal muscles. The significance of such a change in connection to prostaglandin metabolism is discussed.