H. Ruiz

Acid mucopolysaccharides of human aorta

Summary Concentrations of acid mucopolysaccharides (MPS) in the aortic intima and outer layers (externa) with varying extent and severity of atherosclerosis have been studied in Negro females. An increase initially, followed by a decrease, of MPS concentrations was observed as the disease extended from 10 to 55 %. The increase of MPS was characteristic of the fatty streaks and the decrease characteristic of fibrous plaques, complicated and calcified lesions. Chondroitin sulfate B concentrations paralleled the extensiveness of the fatty streaks while it was almost absent in intimai tissue from vessels with fibrous plaques. The chondroitin sulfate B increase may represent an intimai reaction, the disappearance of which coincides with advancement of the disease. It appears that the variations in concentration of MPS in the aorta represent diffuse metabolic changes. Certain early changes predispose to the initiation of atherosclerosis, but progression of the disease is associated with a marked alteration of the content of specific MPS.

Acid mucopolysaccharides of human aorta: Part 1. Variations with maturation*

Summary Acid mucopolysaccharide (MPS) contents in the intima and remaining outer wall of human aortas were studied to observe variations with age. Attempts were made to dissociate changes occurring with aging from those related to atherogenesis by the careful selection of vessels. MPS were isolated from 76 female aortas with and without lesions, and compared to 15 samples from Negro females, the only ones available essentially free of atherosclerotic disease. Aortas available in this population limits the study from extending into older age groups. Detailed MPS analyses were carried out on the lesion-free vessels. The total amount of MPS increases to around the third decade, with more marked changes of compounds occurring in the intima. Chondroitin sulfates C and B both increased in concentration in the intima and then decreased; chondroitin sulfate A progressively increased, while hyaluronic acid and heparitin sulfate showed a tendency to reach peak levels at an early age and then only gradually decreased. Other compounds were noted, but were not in sufficient amount to be clearly characterized. The importance of observing changes of each specific MPS compound and a careful selection of tissue to be studied are to be emphasized in these types of observations.

Acid mucopolysaccharides of fatty streaks in young, human male aortas.

Abstract The mucopolysaccharide (MPS) content and composition of fatty streaks (posterior thoracic and abdominal aorta) were compared to carefully selected un-involved aortic intima (anterior thoracic). An altered composition of MPS in the very earliest lesions occurring in adolescent males was observed. An increase of MPS, chondroitin sulfate C in particular, was found in the fatty streaks associated with spindle cell and extracellular lipid in 12 to 25 year age group. The area of the aorta more susceptible to atherosclerosis showed the most striking changes. These studies are a further indication that MPS contribute to the development of fatty streaks, likely through their interaction with lipids.

Composition of proteoglycans from human atherosclerotic lesions

Proteoglycans from human atherosclerotic lesions and from uninvolved aortic intima were isolated and their composition was studied. The tissues were sequentially extracted by guanidine hydrochloride followed by hydrolysis of the tissue by elastase. Chondroitin sulfate/dermatan sulfate proteoglycans were predominant in guanidine hydrochloride extracts of the tissue. Most of the heparan sulfate proteoglycans were released from the tissue by hydrolysis with elastase. The content of proteoglycan material, measured as uronate per unit weight of wet tissue, was lower in fatty streaks and fibrous plaques than in uninvolved tissue (0.58 and 0.48 mg vs. 0.7 mg/g wet tissue). The distribution of different glycosaminoglycans in guanidine hydrochloride-extracted proteoglycans was similar among the lesions and uninvolved tissue, but varied in the elastase-hydrolyzed extracts. Gel filtration studies suggested that the major proteoglycan material, chondroitin sulfate proteoglycans, from lesions had greater molecular weight than proteoglycans from uninvolved tissue. The studies indicate that alteration in intrinsic composition and molecular size of proteoglycans occurs in atherosclerotic lesions.

Connective Tissue Macromolecular Changes in Rats with Experimentally Induced Diabetes and Hyperinsulinism

A study of connective tissue components from skin of rats with induced diabetes and hyperinsulinism was performed. Diabetes was induced in rats by a single injection of streptozotocin (50 to 75 mg./kg. body weight) and hyperinsulinism by daily injection of NPH insulin (½ to 2½ U.). Serum was analyzed for protein-bound carbohydrates and free sugars. A decrease in serum protein-bound sugars was observed in the diabetic animals. These slightly increased in hyperinsulin state. Acid mucopolysaccharides (MPS), glycoproteins (GP) and collagen were isolated from skin of experimental animals and compared with the controls. The contents of total MPS and GP decreased in diabetic skin; these increased in hyperinsulin state, similar to that observed in human diabetes. Diabetic rat skin had more soluble collagen, while less soluble collagen was observed in hyperinsulin state. It is suggested from these observations that insulin is a driving force toward the synthesis and accumulation of these compounds in connective tissue in experimental hyperinsulinism and, perhaps, in human diabetes with prolonged insulin treatment.

Acid Mucopolysaccharide Changes in Diabetic Kidneys

Studies were conducted on the mucopolysaccharide (MPS) composition of kidneys from seventeen diabetic patients and from six control individuals presumably without renal disease. Thekidney tissues were divided by gross dissection into cortical and medullary portions, and the MPSwere isolated and quantitated from these sections. The contents of hyaluronic acid, heparitin sulfate, and chondroitin sulfates were compared to the clinical and pathological observations on thepatients. According to the MPS pattern of heparitin sulfate and hyaluronic acid, the diabetic kidneys were divided into three groups. Heparitin sulfate was increased fairly consistently in most of the diabetic samples, and was particularly increased in one group with clinically severe diabetes showing the nodular diabetic (Kimmelstiel-Wilson) lesion. Seven of the samples demonstrated a MPS composition somewhat similar to controls, and these were observed to have fewer abnormal changes histologically. A third group showed an increase of hyalufonic acid, and in these kidneys diffuse glomerulosclerosis was the most consistent glomerular lesion. The observations suggest that the two types of specific glomerular lesions found in diabetic kidneys have different cellular origins. The increased heparitin sulfate suggests a relationship of renal changes in diabetes to a vascular origin. A rather interesting similarity of MPS changeshas been observed in amyloidosis and in intima sections of the aorta with atherosclerosis.

Studies of glycosaminoglycan composition and biologic activity of Vessel®, a hypolipidemic agent

Heparin-like glycosaminoglycans (GAG) were isolated from commerical Vessel and their biologic properties studied. Vessel was found to be a mixture of chondroitin sulfates, dermatan sulfate and heparin-like GAG. Chondroitin sulfates and dermatan sulfate in Vessel were hydrolyzed by chondroitinase ABC and the residual Vessel was fractionated on a Dowex-1 Cl- column eluting with a stepwise-increasing concentration of NaCl (1.2--4.0 M). The major fractions eluted at 1.6 M and 1.8 M NaCl were tentatively identified by chemical analysis as heparin-like GAG with somewhat lower sulfate content than standard heparin. Both fractions had lipoprotein lipase-releasing activity and anticoagulant activity similar to heparin, but 1.6 M NaCl fraction had a third of the anticoagulant activity of standard heparin. The 1.8 M NaCl fraction complexed with serum lipoproteins similarly to heparin. In preliminary studies cholesterol-fed rabbits treated with Vessel exhibited somewhat less atherosclerosis than controls.

Changes of acid mucopolysaccharides in the heart involved by amyloidosis

Abstract The acid mucopolysaccharide composition of cardiac tissue from 5 patients with amyloidosis and from control tissue was determined. Heparitin sulfate was consistently increased in the heart and other organs with amyloid deposition. (A corollary study of experimentally induced amyloidosis closely mimicked secondary amyloidosis in man, but in addition to the marked increase of heparitin sulfate in parenchymal organs, a slight increase of this mucopolysaccharide was observed in the heart as well.) In the myocardium, particularly with primary cardiac disease, hyaluronic acid was significantly increased. The observations of acid mucopolysaccharide chemistry in amyloidosis and in diabetic kidneys and the aorta suggest that heparitin sulfate arises from mesangial cells intimately involved in the formation of blood vessels and other cardiovascular structures. Hyaluronic acid, which also increases in the heart in forms of cardiac localization of amyloid, is probably part of the general connective tissue response of the cardiac tissue to disease.

Rapid serum lipoprotein changes in spider monkeys on short-term feeding of high cholesterol-high saturated fat diet.

Summary Serum lipoprotein changes resulting from high cholesterol (0.5% and 2.0%)-high saturated fat diets have been studied in spider monkeys (Ateles geoffroyi). Rapid increase in β-lipoprotein, significant elevation in α-lipoprotein, and marked variations in individual responses to cholesterol intake were observed during these dietary periods.

Variations in the composition of arterial wall isomeric chondroitin sulfate proteoglycans among different animal species

1. Isomeric chondroitin sulfate proteoglycans were extracted from human, bovine, swine and rabbit aortas by 4 M guanidine-HCl and were fractionated and purified by CsCl isopycnic centrifugation, Sepharose CL-4B gel filtration, DEAE-Sepharose ion-exchange chromatography and octyl-Sepharose hydrophobic interaction chromatography. 2. The molecular size and the composition of isomeric chondroitin sulfate proteoglycans varied among species. Variations were also noted in the composition and molecular weight of constituent glycosaminoglycan chains. 3. Observations made on chondroitinase ABC and chondroitinase AC digests of proteoglycans indicate that dermatan sulfate is linked to the core proteins through chondroitin sulfates.