Response of epidermal polyamines to orally administered aromatic retinoid RO 10-9359

Polyamine levels were measured in skin (pure epidermis) and 24-h urine before and 15 days after the start of continuous oral treatment with Etretinate (1 mg/kg/day) in 20 patients with various dermatoses. In uninvolved epidermis, treatment modified levels of spermidine (45% increase, P<0.05) and spermine (30% increase, P<0.05). In urine, the putrescine concentration was significantly altered, incresing from 1.96 to 2.60 μg/mg creat (P<0.05.). During the time interval cosidered, variations in polyamine levels did not reflect the inhibiting mechanism of retinoids on ornithine decarboxylase, the key enzyme in the regulation of polyamine synthesis.