Epidermal ornithine decarboxylase activity and thymidine incorporation following treatment with ultraviolet A combined with topical 8-methoxy-psoralen or anthracene in the hairless mouse

Author:
Publisher website
Google Scholar
Abstract
Epidermal thymidine incorporation, as a measure of DNA synthesis, and ornithine decarboxylase activity [ODC] were estimated in hairless albino mice following phototoxic reactions induced by topical anthracene + UV-A, and topical 8-methoxypsoralen (8-MOP) + UV-A [used for psoriasis therapy]. Both treatments caused depression of epidermal thymidine incorporation to 26% of control values at 4 h; this depression persisted through 24 h following 8-MOP + UV-A. Animals treated with anthracene + UV-A showed a 4-fold increase in thymidine incorporation at 48 h, declining at 72 and 96 h. After 8-MOP + UV-A increased thymidine incorporation was observed between 4 and 10 days, when a plateau of 96 h duration was observed. After treatment with anthracene + UV-A, ODC activity was maximal at 4 h, and exhibited a rapid decline, with normal levels at 48 h. Following 8-MOP, UV-A dose-dependent ODC induction occurred. This was later than that induced by anthracene + UV-A with no detectable activity at 4 or 12 h, and maximum activity at 24 h, the elevation persisting through 96 h. The relationship between ODC induction and epidermal hyperproliferation following these treatments is discussed.

This publication has 15 references indexed in Scilit: