RESUMO
Chondroitin 4-sulfate (Ch 4-S), three dermatan sulfates (DS18, DS45a, DS45b) and hyaluronic acid (HA) were the major glycosaminoglycans (GAG) isolated from the skin of 4 groups of albino rats. The yields from Group 1 (control) were: Ch 4-S, 0.015%; HA, 0.028% and DS (total), 0.098% (w/w). Traces of heparin were detected only in rats irradiated with ultraviolet (UV) light (Group II), in the GAG pool isolated with 45% ethanol. Yields increased by at least 28% (w/w) in Group II, but decreased, except HA's, also by at least 28%, below the level of the control, in irradiated rats that also ingested vitamin E (Group III). The sulfate composition of these GAG determined by infrared spectroscopy was as follows: approx. 17% (w/w) for DS18, 21-30% for DS45a, 21-35% for DS45b and 26-44% for Ch 4-S. A 60-70% (mol/mol) N-acetylation of hexosamine in DS45 was estimated by Fourier transform 1H-NMR spectroscopy; the IdUA composition of this DS was 30-46% (mol/mol), and the uronic acid/hexosamine ratio ranged from 2.50:1 to 1.6:1. The data show UV light irradiation of rat skin to result in an abnormally elevated production of the major GAG and oversulfation of Ch 4-S and DS. These effects are reversed, except for the sulfation of DS45b, when the irradiated animals also ingest vitamin E.
