Alteration of specific binding of prostaglandin F2 alpha by hyperproliferative skin membrane fractions from essential fatty acid-deficient rats.

Specific binding of [3H] PGE2 and [3H] PGF2 alpha to smooth endoplasmic reticulum (SER) membranes prepared from rat skin at various stages of the development of essential fatty acid (EFA)-deficiency syndrome was demonstrated in these studies. The normal SER-binding capacity for [3H] PGE2 per mg of membrane protein was approximately two-fold that for [3H] PGF2 alpha in control rats fed a diet rich in essential fatty acids (EFA). Two weeks following the feeding of the animals with the EFA-deficient diet: histological evaluation revealed hyperplasia and acanthosis of the epidermal layer; a two-fold increase in labeling index (a marker for DNA synthesis) and no alteration in the SER-binding capacity for [3H] PGE2 or [3H] PGF2 alpha. By the 12th week however, labeling index had increased six-fold, accompanied by a five-fold increase in SER-binding capacity for [3H] PGF2 alpha. SER-binding for [3H] PGE2 was relatively unaltered. These results have demonstrated a relationship between marked alteration of skin SER-binding capacity for PGF2 alpha and the increase in epidermal hyperplasia and proliferation characteristic of the skin of the EFA-deficient rat. Refeeding of the animals with EFA-rich diet restored the epidermal proliferation and the SER-binding capacity to PGF2 alpha to normal conditions.