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Query: UMLS:C0004153 (atherosclerosis)
 77,401 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Connective tissue composition of aortas from several non-human primate species has been studied in an effort to relate collagen, elastin, ang glycosaminoglycan (GAG) content to species susceptibility to atherosclerosis. Among the species studied the baboon contained the highest content of GAG in the aorta. While the distribution of individual GAG varied from species to species, heparan sulfate (HS) was the highest GAG in aortas from most of the species. The ratio of HS to chondroitin sulfates (CS) plus dermatan sulfate (DS) was lowest in the baboon, a species relatively less susceptible to atherosclerosis, and highest in the squirrel monkey, a very susceptible primate. If a relationship exists between HS to CS + DS ratio in the aorta and atherosclerosis, the primates can be arranged in the following decreasing order of susceptibility: squirrel, chimpanzee, stump-tailed, rhesus, African green, patas, baboon. In studies of other connective tissue components, the proportion of total collagen to elastin was found lowest in the baboon. Such observations emphasize the importance of connective tissue in the pathogenesis of atherosclerosis.
Atherosclerosis 1978 Jan
PMID:Connective tissue composition of aortas from non-human primates. A comparative study. 41 48

Elastin was extracted from human aortic plaque and adjacent grossly normal intima by the following methods: (1) 0.1 N NaOH at 100 degrees C, (2) hot NaOH and 0.2 M EDTA, (3) 5 M guanidine--HCl and collagenase, (4) guanidine--collagenase and dithioerythritol--urea--sodium dodecyl sulfate, (5) guanidine--collagenase and EDTA, (6) 10% NaCl and collagenase, and (7) NaCl--collagenase and EDTA. All elastin samples contained small amounts of carbohydrate and hydroxyproline. The lipid content of non-plaque intimal elastin samples was small (2--3%), whereas it increased to 4--6% in plaque intima. The lipid composition of elastin preparations varied significantly with the extraction procedure. Elastin from plaque intima contained significantly more cholesterol (50--60%) and less triglyceride and phospholipid than elastin of non-plaque intima (30--50% cholesterol). The contents of free and esterified cholesterol were comparable in all preparations. The main phospholipid in all samples was sphingomyelin, which comprised between 50 and 80% of the total phospholipid. Compared with NaOH-purified elastin, the other elastin samples were characterized by an increased phosphatidyl--choline content, while they all contained an almost equal amount of phosphatidylethanolamine. In elastin samples from plaque intima, the polar amino acids were increased, whereas cross-linking amino acids were decreased. The polarity and hydroxyproline content of elastin samples were slightly decreased after treatment with EDTA or dithioerythritol--urea--sodium dodecyl sulfate.
Atherosclerosis 1979 May
PMID:Elastin--lipid interaction action in the arterial wall. Part 1. Extraction of elastin from human aortic intima. 46 28

After explaining the role of estrogens in normal human physiology with a discussion of fertilization which mentions cytogenetical research, the history of estrogen synthesis, forms of estrogen, and the roles estrogens play in female physiology after birth are discussed. The observation that estrus in an animal was mediated by a chemical agent was made in 1922. In 1927, studies showed that urine of pregnant women contained estrogenic substances, and in 1929, estrone, an oxidation product of estradiol, was isolated from this source. The natural oxidation products of estradiol include, besides estrone, estriol, equilin, and equilenin, these last 3 being very weak estrogens. Conjugated estrogens consist chiefly of sodium estrone sulfate. In 1938, diethylstilbestrol, a nonsteroidal estrogen, was synthesized. A discussion of the estrogens activities when administered orally or parenterally follows; nonsteroidal estrogens are thought to have good oral action as do esterified estrogens. Estrogenic effects on female physiology include secondary sexual characteristics, menstrual cycle, and ovulation. Other estrogen functions mentioned were antidiuretic action, retardation of atherosclerosis, increased calcium deposition in bone, and epiphyseal closure acceleration after initial stimulation. The rationale for and problems with patient package inserts are discussed.
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PMID:Estrogens: their function, uses and hazards. Part 1. 62 25

(1) Acidic glycosaminoglycans (AGAG) were prepared from the inner and outer layers of human aorta and fractionated by Dowex 1-X2 columns. The anticoagulant activity of the fractionated AGAG was measured by the partial thromboplastin time. (2) Heparan sulfates were the main AGAG in the 1.25 M NaCl fraction and were more abundant in the outer layer than in the inner. Likewise, there was more dermatan sulfate in the outer layer. (3) The AGAG in the outer layer showed much greater anticoagulant activity than those in the inner layer, both in the 1.25 M and 1.75 M NaCl fractions. (4) Anticoagulant activity was attributed to the heparan sulfates in the 1.25 M fraction and to the dermatan sulfate in the 1.75 M fraction.
Atherosclerosis 1978 Jan
PMID:Effects of acidic glycosaminoglycans in human aortic inner and outer layers on partial thromboplastin time. 62 29

Intimal tissue from human atherosclerotic aortae was collected by the Dermatome procedure. The tissue was extraved with 5 mM Tris.HCl buffer containing 0.3 M NaCl and 1 mM EDTA, pH 7.4. The ammonium sulfate precipitate between 0.4--0.8 saturation obtained from the extract was fractionated on a DEAE-cellulose column and the effluent was monitored for lipoprotein lipase inhibition employing purified bovine milk enzyme. The substrate used was an emulsion of purified olive oil and tritiated triolein. Human serum was the source of activator of the substrate. A peak of inhibitory activity was eluted between 0.15--0.17 M NaCl. The major component in the purified material had properties similar to a glycoprotein (lipolipin) which has previously been purified from porcine aorta and shown to inhibit lipoprotein lipase activity. The partially purified human inhibitor decreased both the basal and the serum-stimulated activity of milk lipoprotein lipase. The inhibition was non-competitive with respect to serum. However, high levels of triglyceride substrate appeared to relieve the inhibitory effect. It is postulated that the inhibitor may be involved in an interaction with the emulsified lipid denying the enzyme access to its substrate.
Atherosclerosis 1978 Feb
PMID:The in vitro inhibition of bovine milk lipoprotein lipase by a glycoprotein preparation from human atherosclerotic intima. 64 49

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.
Atherosclerosis 1978 Oct
PMID:Studies of glycosaminoglycan composition and biologic activity of Vessel, a hypolipidemic agent. 72 39

A method is presented for grinding and extracting very small samples of tough fibrous tissue from single atherosclerotic lesions of human aortas. Grinding to a powder was easily accomplished while the samples were frozen in liquid nitrogen in a porcelain micromortar. Extractions of the powder were made first in the mortar and then in tapered centrifuge tubes. Salt soluble, dodecyl sulfate--mercaptoethanol--urea soluble and hot alkali soluble fractions were obtained, in addition to a hot alkali insoluble elastin residue from each sample. Variation in the protein composition of 23 samples from the lumenal surface of the severely atherosclerotic aorta of a 58-year-old human male were determined. The proteins soluble in the buffered-saline and the dodecyl sulfate-urea soluble polypeptides from each sample were analyzed by dodecyl sulfate--acrylamide gel electrophoresis. The amino acid compositions of the insoluble elastin fractions were determined. The 5 grossly normal intima samples had very similar gel electrophoresis band patterns and amino acid compositions. The 3 samples of necrotic gruel had markedly different dodecyl sulfate--urea soluble polypeptides than either normal or calcified tissue; they also had elastin fractions whose amino acid compositions were unique in that they contained 10 times more serine than elastin fractions from grossly normal intima. The 3 calcified samples had less saline or dodecyl sulfate soluble protein than either grossly normal or necrotic gruel samples, and had very altered elastin fraction compositions characterized by much higher contents of hydroxylysine than grossly normal intima. The elastin fractions of necrotic gruel and calcified tissue samples had little or no isodesmosine or desmosine, suggesting that little of the elastin found in healthy aorta tissue was present.
Atherosclerosis 1977 Feb
PMID:Variation in proteins of single lesions from the intima of the aorta from a human patient with severe atherosclerosis. 83 51

Three different assays for selective measurement of plasma lipoprotein lipase (LPL) and hepatic triglyceride lipase (H-TGL) were compared. These were: an immunochemical method based on enzyme antibody precipitation (IM), a procedure in which both enzymes were separated by affinity chromatography on small heparin--Sepharose columns (HS), and an assay in which one enzyme was inhibited by protamine sulfate (PS). Good correlations were found between the immunochemical and the heparin--Sepharose method, but not between these and the protamine sulfate assay procedure. The IM was then used to evaluate the effect of clofibrate on the two lipolytic enzymes. It was found that both in normals and in patients with Type IV hyperlipoproteinemia, clofibrate treatment leads to a specific increase of plasma LPL while H-TGL activity remains almost unaffected. The magnitude of the LPL response was different in normals and in patients with endogenous hyperlipoproteinemia. Furthermore, in normals the maximal increase of LPL activity was already reached one week after drug treatment was begun, while in hypertriglyceridemic patients, this effect was not evident prior to four weeks of clofibrate treatment. The marked enzyme increase following clofibrate administration indicates that an increased peripheral removal rate for triglycerides is one major mechanism responsible for the lipid-lowering effect of this drug.
Atherosclerosis 1977 Apr
PMID:Comparison of assay methods for selective measurement of plasma lipase. The effect of clofibrate on hepatic and lipoprotein lipase in normals and patients with hypertriglyceridemia. 85 26

Hyaluronate (HA), heparan sulfate (HS), dermatan sulfate (DS) and isomeric chondroitin sulfates (CS) were measured in vascular walls of 9-10 months old normal and hypophysectomized female beagles treated with sex hormones. Following hypophysectomy the animals were maintained for 8 weeks without any hormonal replacement therapy and then they were exposed for 3 weeks to parenteral treatment with sex hormones. One group received twice weekly 25 mg testosterone, another group was given the same amount of progesterone, and a third group received on day 1 and day 14, estrogens in 2 injections, consisting of a mixture of 10 mg short-acting estradiol-17-phenylpropionate and 2.5 mg long-acting estradiol benzoate. After 11 weeks all animals were sacrificed, coronary arteries and aortas were immediately removed and the latter were divided into three segments: arch, thoracic and abdominal. Removal of the pituitary led to a reduction of the HA content in the aortic arch and thoracic segment, but coronary arteries and abdominal aorta were not affected. The main consequence of hypophysectomy both in the entire aorta and in coronary arteries was a sharp reduction of the sulfated glycosaminoglycan (GAG) content. All three hormones produced a modest rise in the HS content of coronary arteries. A more definite response was seen in the thoracic aorta where each of the three hormones raised the low DS content to normal levels. Concerning the effect of sex hromones on aortic GAG other than DS, TESTOSTERONE RAISED THE CS content towards normal in thoracic and abdominal segments, while estrogen by doubling the normal HA concentration was particularly potent in the abdominal aorta. It is conceivable that the different sensitivity of various segments of aorta and coronary arteries to sex (and other) hormones in terms of regulating GAG metabolism may prove to be of relevance to the uneven distribution of lesions in degenerative vascular disease.
Atherosclerosis 1977 Jun
PMID:The effect of sex hormones on glycosaminoglycan content of canine aorta and coronary arteries. 90 20

Fifteen chicken tissues were examined for mast cells. Numerous mast cells were found in peritoneum and spleen. The sulfated mucopolysaccharides extracted from these two tissues, corresponding in amount to that in mast cells, were found to be dermatan sulfate, chondroitin sulfate and heparitin sulfate but no evidence of heparin. We have shown a similar situation occurs in the rabbit which is also highly susceptible to the production of atherosclerosis by diet. These observations provide further evidence of a role for heparin and mast cells in limiting atherogenesis.
Atherosclerosis 1976 Oct
PMID:Susceptibility to experimental atherosclerosis: relation to mast cells and heparin. 98 95


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