Effects of topical prostaglandin E analogue on normal hairless mouse epidermal DNA synthesis

The in vivo topical effects of a synthetic analogue of prostaglandin E2 (15(S)-15-methyl PGE2 methyl ester [PGE2 analogue]), have been studied on the epidermis of hairless mice. One microgram of the PGE2 analogue increased DNA synthesis significantly by 5 hr, a maximum increase of 390% was reached by 12 hr, and DNA synthesis returned to control levels by 24 hr. Twenty micrograms of the PGE2 analogue reduced epidermal DNA synthesis for 12 hr after application, DNA synthesis was increased at 24 hr, returning to control levels by 48 hr. One hundred micrograms of topical PGE2 had no significant effect on epidermal DNA synthesis over 48 hr, but 1 mug of intradermal PGE2 increased DNA synthesis by 160% at 24 hr. These results suggest that topical 15(S)-15-methyl PGE2 methyl ester is biologically active compared with PGE2.