Effects of treatment with dithranol, etretinate and a combination of dithranol and etretinate on epidermal metabolism and histology. Mouse tail assay.
The mouse tail assay is useful for studying dermatological therapeutics that influence epidermal differentiation. The effect of dithranol (0.1% w/v in acetone, topically; DI), etretinate (2 mg/kg body weight/d, orally; ET) and of the simultaneous administration of both preparations (DI/ET) on the epidermis of the mouse tail was examined. The thickness of the epidermis, the number of nuclei per defined epidermal section, and the development of a granular layer in the interfollicular areas were determined. The incorporation of 3H-thymidine-triphosphate onto the DNA and global protein synthesis were also determined in vitro. The incorporation rates of leucine and histidine into protein in vitro were measured separately. DI caused retention acanthosis and at the same time orthokeratotic differentiation of the interfollicular areas of the epidermis. Light microscopy of the tail epidermis after application of ET showed no significant changes. Administration of ET/DI yielded the same effects as treatment with DI alone. DI partially reduced the biochemical parameters. ET increased DNA-polymerase activity, global protein synthesis, and the incorporation rate of histidine. The biochemical results after treatment with DI/ET were very similar to those obtained after DI administration. From the histological and biochemical results it is therefore concluded that the simultaneous administration of DI and ET produces the same effects as DI treatment alone.
Lubach
D
D
Department of Dermatology, Medizinische Hochschule Hannover, Fed. Rep. of Germany.
Kietzmann
M
M
D000818:Animals; D000875:Anthralin / Q000008:administration & dosage / Q000494:pharmacology*; D002454:Cell Differentiation; D004247:DNA / Q000378:metabolism; D004347:Drug Interactions; D000078404:Epidermal Cells; D004817:Epidermis / Q000187:drug effects* / Q000378:metabolism; D005050:Etretinate / Q000008:administration & dosage / Q000494:pharmacology*; D006639:Histidine / Q000378:metabolism; D007930:Leucine / Q000378:metabolism; D008297:Male; D051379:Mice; D014176:Protein Biosynthesis; D013623:Tail; D013942:Thymine Nucleotides / Q000378:metabolism
D013942:Thymine Nucleotides; D006639:Histidine; D005050:Etretinate; D004247:DNA; D007930:Leucine; C024157:thymidine 5'-triphosphate; D000875:Anthralin