Prostaglandin binding to membrane fractions from rat skin

[3H]PGE2 and [3H]PGF2alpha bound to PM and ER prepared from rat skin with high affinity and specificity. Maximum binding was achieved in the presence of Ca2+ (5.0 x 10(-4) M). Unlabeled PGE2 and PGF2alpha inhibited [3H] PGE2alpha binding to ER in a dose-dependent manner with approximately 90% inhibition at a concentration of 1.5 x 10(-10) M. PGF2alpha inhibited approximately 40% of the same concentration. A variety of fatty acids inhibited binding less than 30% at 3.0 x 10(-10) M. The [3H]PGE2 binding was inactivated by pronase, trypsin, and heat treatment. Decreased specific binding of [3H]PGE2 to membrane fractions of EFA-deficient rats was demonstrated in our experiments, whereas binding of [3H]PGF2alpha was elevated. These results indicate that the abnormality of skin under EFA deficiency alters the ability of the membrane preparations to bind prostaglandins.