Stimulation of epidermal protein synthesis in vivo by topical triamcinolone acetonide.
The rate of epidermal protein synthesis in vivo was determined in the hairless mouse by a method in which a large dose of [3H]phenylalanine (150 mumol/100 g body wt.) is administered via the tail vein. The epidermal free phenylalanine specific radioactivity rapidly rose to a plateau value which by 10 min approached that of plasma, after which it declined. This dose of phenylalanine did not of itself alter protein synthesis rates, since incorporation of co-injected tracer doses of [3H]lysine and [14C]threonine was unaffected. The fractional rate of protein synthesis obtained for epidermis was 61.6%/day, whereas values for liver and gastrocnemius muscle in the same group of mice were 44%/day and 4.8%/day respectively. When expressed on the basis of RNA content, the value for epidermis (18.6 mg of protein/day per mg of RNA) was approx. 3-fold higher than those for liver and gastrocnemius muscle. Topical administration of 0.1% triamcinolone acetonide increased the epidermal fractional protein synthesis rate by 33% after 1 day and by 69% after 7 days, compared with vehicle-treated controls. These effects were entirely accounted for by the increase in protein synthesis rates per mg of RNA. RNA/protein ratios were unaffected by this treatment.
D000279:Administration, Cutaneous; D000818:Animals; D004817:Epidermis / Q000187:drug effects / Q000378:metabolism*; D008099:Liver / Q000378:metabolism; D008239:Lysine / Q000378:metabolism; D008297:Male; D051379:Mice; D008812:Mice, Hairless; D009132:Muscles / Q000378:metabolism; D010649:Phenylalanine / Q000378:metabolism / Q000494:pharmacology; D014176:Protein Biosynthesis; D013268:Stimulation, Chemical; D013912:Threonine / Q000378:metabolism; D014222:Triamcinolone Acetonide / Q000008:administration & dosage / Q000494:pharmacology*
D013912:Threonine; D010649:Phenylalanine; D014222:Triamcinolone Acetonide; D008239:Lysine