冠動脈におけるムコ多糖分子種解析ならびに水・脂肪含量に関する研究

Acidic glycosaminoglycans (AGAG) in arterial tissues may play a role in the process of atherosclerosis as negatively charged substances. Previous work shows that arterial AGAG possess anti-atherogenic, anti-thrombogenic and anticoagulant properties. Little biochemical information is available on the AGAG composition of coronary arteries. In analytical processing of AGAG, we succeeded in precisely analyzing AGAG by microenzymatic assay methods, using chondroitinases, hyaluronidase and heparitinase. The data obtained indicated that the AGAG compositions of coronary arteries differ both according to the topographical site and the degree of atherosclerosis. The AGAG content of coronary arteries was relatively higher in the main branches than in their distal parts, and it decreased with increasing severity of atherosclerosis.<br>Fresh human coronary arteries were prepared from 48 male subjects in their fifth decade, and then divided into three parts: the left and right branches and their distal parts. The specimens, thus prepared, were then classified into 3 grades on the basis of the severity of atherosclerosis. The preparation of AGAG from coronary arteries were performed principally by the method reported in previous papers. The specimens were digested with pronase and treated with 4M sodium hydroxide and trichloroacetic acid. After the specimens were centrifuged, the supernatant was dialyzed against running tap and distilled water. The undialyzed AGAG were completely precipitated by addition of 5% cetylpyridinium chloride. The yield of uronic acid in units of AGAG was determined; it varied between 3 and 5.5mg/g defatted dry tissue weight. The AGAG thus prepared were applied onto a Dowex 1-X2 column (0.7×20cm) and eluted with 0.25M and 3.0M NaCI. The latter eluate was desalted by passing through a Sephadex G-10 column (0.7×25cm) and then used for the subsequent chemical analysis.<br>Thus, the acidic glycosaminoglycans (AGAG) of the human coronary arteries (the left and right branches and their distal parts) were analyzed by enzymatic methods employing chondroitinases, hyaluronidase and heparitinase. The AGAG content of human coronary arteries was highest in the left branch, intermediate in the right branch and lowest in the distal parts. Some compositional differences in AGAG were found in these three parts. The amount of AGAG in the coronary arterial tree decreased with increasing severity of atherosclerosis. The main AGAG were heparan sulfate (HS) and chondroitin 6-sulfate (C-6S), constituting 33-38% and 24-36% of the total AGAG, respectively. Dermatan sulfate (DS) and chondroitin 4-sulfate (C-4S) each comprised 1/5-1/10 of the total AGAG. Hyaluronic acid (HA) and oversulfated DS comprised smaller proportions of the total AGAG. A small amount of heparin was occasionally detected in the coronary arteries, particularly in the distal parts. The lipid content of the main branches was increased in mildly atherosclerotic parts but diminished in severely affected parts. The water content was relatively higher in the main branches and decreased with severity of atherosclerosis. A possible function of these AGAG in atherosclerosis is discussed with respect to the compositional changes.