ABSTRACT
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.
Subject(s)
Glycosaminoglycans/radiation effects , Radiation-Protective Agents/pharmacology , Skin/radiation effects , Ultraviolet Rays , Vitamin E/pharmacology , Animals , Chondroitin Sulfates/metabolism , Chondroitin Sulfates/radiation effects , Dermatan Sulfate/metabolism , Dermatan Sulfate/radiation effects , Diet , Glycosaminoglycans/metabolism , Hyaluronic Acid/metabolism , Hyaluronic Acid/radiation effects , Rats , Rats, Sprague-DawleyABSTRACT
Anhydrous sodium sulfate (Na2SO4) was analyzed at varying concentrations by infrared (ir) spectroscopy. A standard curve was obtained from a linear plot of sulfate (SO2-(4] concentration vs the weight of the ir band area of S = O stretching. Standard chondroitin 4-sulfate, chondroitin 6-sulfate, heparan sulfate, heparin, keratan sulfates, and various dermatan sulfates isolated from human and rat skins were also studied by ir spectroscopy. The spectrum of every glycosaminoglycan (GAG) displayed an ir band around 1230 cm-1 which originated from S = O stretching of sulfate esters. Therefore, the weight of the latter band was employed to quantify sulfate, by using the standard curve indicated above. Sulfate was also estimated quantitatively by the gelatin/BaCl2 method of K.S. Dodgson and R.G. Price (Biochem. J. 1962, 84, 106-110). The sulfate composition determined by ir spectroscopy ranged from 8.5 to 22.1% (w/w), and agreed closely with the values obtained chemically. In the ir spectroscopy method, sulfate was determined using the polymer forms of the GAGs. After analysis, these heteropolysaccharides were recovered unaffected in a yield greater than 95%. The data show that the infrared spectroscopy technique, in addition to being sensitive and reliable, is much more economical than the chemical procedures currently employed to quantify GAG sulfate.
