| For medical practitioners and the general public - Cholesterol Journal Article Catalog. |
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| Antihypertensive treatment and serum cholesterol: results of population-based surveys in the German Cardiovascular Prevention Study Helmert, U. and S. Shea (1997), Rev Environ Health 12(4): 253-60. Abstract: We analyzed the data from three cross-sectional, population-based surveys in West Germany to evaluate the effect of antihypertensive drug therapy on the level of serum cholesterol in German residents (18,344 males; 19,137 females) aged 25-69 years, after excluding persons with missing values (N = 5529) for any study variable. The data were obtained from the national and regional health surveys that were conducted during the years 1984-1992, within the framework of the German Cardiovascular Prevention Study (GCP). The response rates were between 66.0% and 71.4% for the national surveys and between 65.9% and 83.3% for the regional surveys. Blood-pressure and non-fasting cholesterol measurements were carried out under strictly standardized conditions. Multiple linear regression analysis was used to compare the age-adjusted mean value and prevalence for each of the following study variables: total serum cholesterol, HDL-cholesterol, non-HDL cholesterol, and the ratio of HDL cholesterol/total cholesterol for users and non-users of antihypertensive medications. Antihypertensive medications were reportedly taken during the seven days preceding the survey examination by 7.8% of all males and 10.4% of all females. The beta-blocker type of medication was prescribed most frequently for lowering high blood pressure. In both genders, the strongest age-adjusted effect of an increase in cholesterol level was found for beta-blockers. The difference in the age-adjusted means for non-HDL cholesterol values between users and non-users of beta-blockers was 9.2 mg/dL (p < 0.001) in males and 9.0 mg/dL (p < 0.001) in females. Regression analysis carried out to control for several potential confounders confirmed the results. The findings suggest that mass treatment of hypertension with beta-blockers may be associated with reductions in benefit because of an increase in non-HDL and a decrease in HDL cholesterol levels. |
| Anti-metastatic activity in vivo of MDP-L-alanyl-cholesterol (MTP-Chol) entrapped in nanocapsules Yu, W. P., G. M. Barratt, et al. (1991), Int J Immunopharmacol 13(2-3): 167-73. Abstract: A lipophilic muramylpeptide (MTP-Chol), capable of rendering macrophages cytostatic towards tumour cells, was encapsulated within polyisobutylcyanoacrylate nanocapsules and administered to mice carrying an experimental model of liver metastasis. Treatment by intravenous injections twice a week beginning before the establishment of metastases significantly reduced the number of liver colonies. Treatment started later was less effective. The dose of MTP-Chol in each injection, and the tumour burden in the mice did not change the percentage inhibition of metastases significantly. Anti-metastatic activity was also observed after administering nanocapsules containing MTP-Chol by the oral route. |
| Anti-metastatic activity of MDP-L-alanyl-cholesterol incorporated into various types of nanocapsules Barratt, G., F. Puisieux, et al. (1994), Int J Immunopharmacol 16(5-6): 457-61. Abstract: A lipophilic immunomodulator (MTP-Chol) was included in nanocapsules prepared from different polymers and the anti-metastatic effects of the resulting drug delivery systems were evaluated in a murine model of liver metastases. Loaded nanocapsules were effective if they were given 2 days before tumor inoculation. Neither the nature of the polymer nor the total dose of immunomodulator affected the antimetastatic capacity. However, enhanced anti-metastatic activity was obtained when indomethacin nanocapsules were associated with MTP-Chol nanocapsules. These results show that nanocapsules containing an immunomodulator possess anti-metastatic activity, but only when given as a prophylactic treatment; this would correspond, in the clinic, to patients undergoing surgery for a primary tumor and at risk of developing liver metastases. |
| Anti-obesity effect of cholest-4-en-3-one, an intestinal catabolite of cholesterol, on mice Suzuki, K. (1993), J Nutr Sci Vitaminol (Tokyo) 39(5): 537-43. Abstract: An anti-obesity effect was observed for cholest-4-en-3-one (cholestenone) which is an intestinal catabolite of cholesterol. Body weight gain and body fat accumulation of CDF1 mice were inhibited by 0.5% dietary exposure to this chemical. Dose response for the effect of cholestenone was found to increase as the dose rose from 0.1 to 0.3% and 0.5%. No obvious anomaly due to consumption of cholestenone was detected by necropsy and clinical observation. The mechanism of this effect of cholestenone is not known at present, but it was not due to anorexia. |
| Antioxidant activity of tocopherols, tocotrienols, and gamma-oryzanol components from rice bran against cholesterol oxidation accelerated by 2,2'-azobis(2-methylpropionamidine) dihydrochloride Xu, Z., N. Hua, et al. (2001), J Agric Food Chem 49(4): 2077-81. Abstract: The antioxidant activities of vitamin E (alpha-tocopherol, alpha-tocotrienol, gamma-tocopherol, and gamma-tocotrienol) and gamma-oryzanol components (cycloartenyl ferulate, 24-methylenecycloartanyl ferulate, and campesteryl ferulate) purified from rice bran were investigated in a cholesterol oxidation system accelerated by 2,2'-azobis(2-methylpropionamidine) dihydrochloride. All components exhibited significant antioxidant activity in the inhibition of cholesterol oxidation. The highest antioxidant activity was found for 24-methylenecycloartanyl ferulate, and all three gamma-oryzanol components had activities higher than that of any of the four vitamin E components. Because the quantity of gamma-oryzanol is up to 10 times higher than that of vitamin E in rice bran, gamma-oryzanol may be a more important antioxidant of rice bran in the reduction of cholesterol oxidation than vitamin E, which has been considered to be the major antioxidant in rice bran. The antioxidant function of these components against cholesterol oxidation may contribute to the potential hypocholesterolemic property of rice bran. |
| Antioxidant effect of Ebselen (PZ 51): peroxidase mimetic activity on phospholipid and cholesterol hydroperoxides vs free radical scavenger activity Maiorino, M., A. Roveri, et al. (1992), Arch Biochem Biophys 295(2): 404-9. Abstract: The selenocompound Ebselen (PZ 51) is a potent inhibitor of lipid peroxidation. This antioxidant effect has been previously attributed both to a peroxidase mimetic activity and to a free radical scavenging capability. In the present paper the latter is ruled out by competition kinetic analysis based on the inhibition of carotenoid bleaching by hydroperoxyl radicals. Furthermore, evidence is reported indicating that Ebselen exhibits a peroxidase activity extended to cholesterol and cholesterol ester hydroperoxides, besides phospholipid hydroperoxides. According to this, we propose that the unique mechanism of the antioxidant capacity of Ebselen is the reduction of lipid hydroperoxides present in liposomes or lipoproteins, eventually leading to the prevention of hydroperoxide-dependent peroxidation. |
| Antioxidant status, lipoprotein profile and liver lipids in rats fed on high-cholesterol diet containing currant oil rich in n-3 and n-6 polyunsaturated fatty acids Vecera, R., N. Skottova, et al. (2003), Physiol Res 52(2): 177-87. Abstract: Plant-based n-3 polyunsaturated fatty acids (PUFA) possess a prospective antiatherogenic potential. Currant oil from Ribes nigrum L. is one of the few plant oils containing PUFAn-3 (15.3 mol%) in addition to PUFAn-6 (60.5 mol%). This study was aimed at comparing the effects of currant oil with those of lard fat, rich in saturated (43.8 mol%) and monounsaturated (47.0 mol%) fatty acids, on antioxidant parameters, the lipoprotein profile and liver lipids in rats fed on 1 % (w/w) cholesterol diets containing either 10 % of currant oil (COD) or lard fat (LFD). After 3 weeks of feeding, the COD induced a significant decrease in blood glutathione (GSH) and an increase in Cu(2+) induced oxidizability of serum lipids, but did not affect liver GSH and t-butyl hydroperoxide-induced lipoperoxidation of liver microsomes. Although the COD did not cause accumulation of liver triacylglycerols as LFD, the lipoprotein profile (VLDL, LDL, HDL) was not significantly improved after COD. The consumption of PUFAn-3 was reflected in LDL as an increase in eicosapentaenoic and docosahexaenoic acid. These results suggest that currant oil affects positively the lipid metabolism in the liver, above all it does not cause the development of a fatty liver. However, adverse effects of currant oil on the antioxidant status in the blood still remain of concern. |
| Antioxidative activity of green tea polyphenol in cholesterol-fed rats Yokozawa, T., T. Nakagawa, et al. (2002), J Agric Food Chem 50(12): 3549-52. Abstract: This study investigated the effects of green tea polyphenol on the serum antioxidative activity and cholesterol levels of cholesterol-fed rats and compared them with those of probucol, an antioxidant hypocholesterolemic agent. To evaluate the antioxidative activity, the susceptibility to oxidative modification of low-density lipoprotein (LDL) isolated from the serum of cholesterol-fed rats was measured, as was the serum antioxidative activity using the spontaneous autoxidation system of brain homogenate. Administration of green tea polyphenol effectively inhibited LDL oxidation and elevated serum antioxidative activity to the same degree as probucol. However, higher amounts of polyphenol than probucol needed to be administered to reduce the total, free, and LDL cholesterol levels. Furthermore, green tea polyphenol increased the levels of high-density lipoprotein (HDL) cholesterol, leading to dose-dependent improvement of the atherogenic index, an effect that was not seen with probucol. Thus, green tea polyphenol may exert an antiatherosclerotic action by virtue of its antioxidant properties and by increasing HDL cholesterol levels. |
| Antioxidative activity of naringin and lovastatin in high cholesterol-fed rabbits Jeon, S. M., S. H. Bok, et al. (2001), Life Sci 69(24): 2855-66. Abstract: The consumption of a cholesterol-enriched diet increases the degree of lipid peroxidation, which is one of the early processes of atherosclerosis. The aim of this trial was to determine the antioxidative effects of the citrus bioflavonoid, naringin, a potent cholesterol-lowering agent, compared to the cholesterol-lowering drug, lovastatin, in rabbits fed a high cholesterol diet. Male rabbits were served a high-cholesterol (0.5%, w/w) diet or high-cholesterol diet supplemented with either naringin (0.5% cholesterol, 0.05% naringin, w/w) or lovastatin (0.5% cholesterol, 0.03% lovastatin, w/w) for 8 weeks to determine the plasma and hepatic lipid peroxide, plasma vitamin A and E levels, and hepatic hydrogen peroxide levels, along with the hepatic antioxidant enzyme activities and gene expressions. Only the lovastatin group showed significantly lower plasma and hepatic lipid peroxide levels compared to the control group. The naringin supplementation significantly increased the activities of both hepatic SOD and catalase by 33% and 20%, respectively, whereas the lovastatin supplementation only increased the catalase activity by 23% compared to control group. There was no difference in the GSH-Px activities between the various groups. Content of H2O2 in hepatic mitochondria was significantly lower in groups supplemented with lovastatin and naringin than in control group. However, there was no difference in cytosolic H2O2 content in liver between groups. The concentration of plasma vitamin E was significantly increased by the naringin supplementation. When comparing the antioxidant enzyme gene expression, the mRNA expression of SOD, catalase and GSH-Px was significantly up-regulated in the naringin-supplemented group. Accordingly, these results would appear to indicate that naringin, a citrus bioflavonoid, plays an important role in regulating antioxidative capacities by increasing the SOD and catalase activities, up-regulating the gene expressions of SOD, catalase, and GSH-Px, and protecting the plasma vitamin E. In contrast, lovastatin exhibited an inhibitory effect on the plasma and hepatic lipid peroxidation and increased the hepatic catalase activity in high-cholesterol fed rabbits. |
| Antioxidative functions of natto, a kind of fermented soybeans: effect on LDL oxidation and lipid metabolism in cholesterol-fed rats Iwai, K., N. Nakaya, et al. (2002), J Agric Food Chem 50(12): 3597-601. Abstract: Natto water-soluble fractions, low-molecular-weight viscous substance, and soybean water extract, which had an inhibitory effect on the oxidation of low-density lipoproteins (LDL) in vitro, were fed to rats for 3 weeks. These fractions had no influence on the growth of rats, which were fed a basal diet containing 1% cholesterol, but lowered plasma triglyceride and total cholesterol. Inhibition of copper-oxidation of plasma and LDL ex vivo, and a reduction in lipid peroxidation in liver and aorta in vivo, were also observed. The antioxidant enzymes were not induced in rats fed natto fraction diets. These results demonstrate that ingestion of the natto fractions led to inhibition of LDL oxidation, and that the fractions perform direct antioxidant action in the body. It is suggested that natto fractions might help to prevent arteriosclerosis, as they appear to reduce lipid peroxidation and improve lipid metabolism. |
| Anti-oxidative properties of fluvastatin, an HMG-CoA reductase inhibitor, contribute to prevention of atherosclerosis in cholesterol-fed rabbits Rikitake, Y., S. Kawashima, et al. (2001), Atherosclerosis 154(1): 87-96. Abstract: Studies in vitro reveal that fluvastatin, an HMG-CoA reductase inhibitor, has a strong DPPH radical scavenging activity and achieves concentration-dependent inhibition of copper- and cell-induced oxidation of low-density lipoprotein (LDL). To further examine the anti-oxidative activity of fluvastatin in vivo, we elucidated the effects of chronic treatment with fluvastatin at a dose insufficient to reduce plasma cholesterol levels (2 mg/kg per day) on vasomotion and vascular oxidative stress in thoracic aortas of 0.5% cholesterol-fed rabbits. After 12 weeks of dietary treatment, aortic segments from rabbits fed cholesterol alone showed impaired endothelium-dependent relaxation responses to acetylcholine and A23187 compared to normal chow-fed rabbits in association with a significant increase in plasma total cholesterol levels. In contrast, although plasma total cholesterol levels were not different from those in control cholesterol-fed rabbits, aortic segments from fluvastatin-treated rabbits showed normal relaxation. Compared with rabbits fed cholesterol alone, fluvastatin treatment decreased susceptibility of LDL to ex vivo copper-induced oxidation, reduced vascular superoxide generation, and atheromatous plaque formation. In conclusion, the potent anti-oxidative properties of fluvastatin in addition to its cholesterol-lowering activity appear to contribute to its anti-atherosclerotic effect in vivo. |
| Antiperoxide effects of S-allyl cysteine sulphoxide isolated from Allium sativum Linn and gugulipid in cholesterol diet fed rats Sheela, C. G. and K. T. Augusti (1995), Indian J Exp Biol 33(5): 337-41. Abstract: Cholesterol containing diet significantly increased not only the body weight, but also the weight of liver and adipose tissue of rats. This is accompanied by a significant increase in blood lipids, atherogenic index and lipid peroxidation and a significant decrease in reduced glutathione level, superoxide dismutase and catalase activities in tissues. Treatment with S-allyl cysteine sulphoxide reverses the deleterious effects of cholesterol diet significantly and almost as effectively as gugulipid. |
| Anti-pneumolysin activity of commercially available alpha 1-antitrypsin is due to cholesterol impurities Rubins, J. B. and M. R. Freiberg (1994), Microb Pathog 16(3): 221-8. Abstract: Pneumolysin (PLY), the principal cytolytic toxin of Streptococcus pneumoniae, may be important in the pathogenesis of acute lung injury during pneumococcal pneumonia. However, the local host defenses that limit PLY injury to lung tissues have not been characterized. We investigated the ability of a commercial preparation of alpha 1-antitrypsin (alpha 1-AT), a major plasma anti-proteinase, to inhibit PLY. At normal plasma concentrations, the alpha 1-AT preparation prevented PLY injury to bovine pulmonary artery endothelial cells, rat alveolar epithelial cells, and human erythrocytes. The alpha 1-AT preparation selectively inhibited thiol-activated bacterial toxins; it was inactive against snake venom hemolysins, mastoparan, and oxygen-stable bacterial toxins. Biochemical characterization of the alpha 1-AT preparation and comparison with other available alpha 1-AT preparations revealed that this inhibitory activity was due to contamination with nanomolar concentrations of cholesterol. Characterization of non-immune human plasma anti-pneumolysin activity showed that beta-lipoprotein fractions contain the major inhibitory activity. We caution other investigators that the inhibition of bacterial virulence by these alpha 1-AT preparations may indicate toxin-mediated, rather than protease-mediated, mechanisms. |
| Antiproliferative effects of SR31747A in animal cell lines are mediated by inhibition of cholesterol biosynthesis at the sterol isomerase step Labit-Le Bouteiller, C., M. F. Jamme, et al. (1998), Eur J Biochem 256(2): 342-9. Abstract: SR31747A is a new sigma ligand exhibiting immunosuppressive properties and antiproliferative activity on lymphocyte cells. Only two subtypes of sigma receptor, namely the sigma1 receptor and emopamil-binding protein, have been characterised molecularly. Only the sigma1 receptor has been shown to bind (Z)N-cyclohexyl-N-ethyl-3-(3-chloro4-cyclohexylphenyl)pro pen-2-ylamine hydrochloride (SR31747A) with high affinity. It was demonstrated that the SR31747A effect on the inhibition of T-cell proliferation was consistent with a sigma1 receptor-mediated event. In this report, binding experiments and sterol isomerase assays, using recombinant yeast strains, indicate that the recently cloned emopamil-binding protein is a new SR31747A-binding protein whose activity is inhibited by SR31747A. Sterol analyses reveal the accumulation of a delta8-cholesterol isomer at the expense of cholesterol in SR31747A-treated cells, suggesting that cholesterol biosynthesis is inhibited by SR31747A at the delta8-delta7 sterol isomerase step in animal cells. This observation is consistent with a sterol isomerase role of the emopamil-binding protein in the cholesterol biosynthetic pathway in animal cells. In contrast, there is no evidence for such a role of the sigma1 receptor, in spite of the structural similarity shared by this protein and yeast sterol isomerase. We have found that SR31747A also exerts anti-proliferative effects at nanomolar concentrations on various established cell lines. The antiproliferative activity of SR31747A is reversed by cholesterol. Sterol-isomerase overproduction enhances resistance of CHO cells. This last observation strongly suggests that sterol isomerase is implicated in the antiproliferative effect of the drug in established cell lines. |
| Antisense effects of cholesterol-oligodeoxynucleotide conjugates associated with poly(alkylcyanoacrylate) nanoparticles Godard, G., A. S. Boutorine, et al. (1995), Eur J Biochem 232(2): 404-10. Abstract: Oligonucleotides covalently attached to a cholesteryl moiety are more stable in biological media and better taken up by eukaryotic cells. However, their anchoring in hydrophobic cellular membranes and endosomes after endocytosis restricts their access to cellular nucleic acids. New methods of cellular delivery and the biological activity of the conjugates were studied. The cholesteryl residue was conjugated via disulfide bond to the 5' or 3' terminal phosphate group of two oligodeoxyribonucleotide dodecamers complementary to the mutated region of Ha-ras oncogene mRNA. The conjugates were able to form complementary duplexes with the mutated 27-b target fragment of mRNA but not with the wild-type sequence. Efficient sequence-specific RNase H cleavage of complementary mRNA was induced with low (< or = 500 nM) concentrations of the conjugates. At higher concentrations, this cleavage was progressively inhibited, probably due to an interaction between RNase H and the cholesterol residue. The hydrophobic conjugates could be adsorbed onto poly(isohexylcyanoacrylate) nanoparticles via their cholesteryl moieties and delivered to eukaryotic cells. Cholesterol-conjugated oligonucleotides were able to sequence-specifically inhibit the proliferation of T24 human bladder carcinoma cells in culture. |
| Antisteatotic effects of four kinds of dietary fibers in rats fed on high cholesterol diet: a preliminary morphometric analysis Zhang, Y., Z. Zheng, et al. (1992), Hua Xi Yi Ke Da Xue Xue Bao 23(1): 75-8. Abstract: The hypolipidaemic and antisteatotic effects of the Konnyaku Powder (KP) have been reported before. In order to evaluate further the antisteatotic role played by KP, the effects of KP on the levels of liver lipid and on the hepatic histopathology and morphometry in comparison with those of pectin, algin and agar were studied. Sixty Wistar strain rats were divided into 6 groups: a normal diet group, a high cholesterol diet group (HC), and 4 test groups, in which the animals were fed on a diet similar to that of the high cholesterol diet group with addition of KP, pectin, algin or agar at a dosage of 5%, respectively. All the animals were killed at the end of the diet treatment for 9 weeks. The results showed that relative liver weights were lower in four experimental groups than in the HC group. The levels of total and free cholesterol, and triglyceride in the liver were lower in KP group than in HC group and in the other three experimental groups. Hepatic histopathology and morphometric examination indicated that antisteatotic effects of KP appeared to be much more significant than those of the other fibers. |
| Antithrombotic potential of olive oil administration in rabbits with elevated cholesterol De La Cruz, J. P., M. A. Villalobos, et al. (2000), Thromb Res 100(4): 305-15. Abstract: Olive oil is the main source of dietary fatty acids in the Mediterranean region. The objective of this study was to evaluate the effect of dietary supplementation with virgin olive oil in an experimental model with rabbits fed an atherogenic diet (saturated fat 48% of total fat). Four different groups of 10 animals each were studied: (1) normolipemic diet (NLD), (2) atherogenic diet or saturated fatty acid-enriched diet (SFAED), (3) NLD with 15% olive oil (NLD+OLIV), and (4) SFAED with 15% virgin olive oil (SFAED+OLIV). The animals were fed the experimental diets for 6 weeks, after which we determined serum lipid profile (total cholesterol, HDL-cholesterol, and triglycerides), platelet aggregation, platelet thromboxane B(2), aortic prostacyclin, and platelet and vascular lipid peroxidation. Scanning electron microscopic images of the vascular endothelium were studied, as were morphometric parameters in the arterial wall and thrombogenicity of the subendothelium (annular perfusion chamber). Animals fed the SFAED showed platelet hyperactivity and increased subendothelial thrombogenicity. Animals fed the SFAED+OLIV showed, compared with the SFAED group, an improved lipid profile with decreased platelet hyperactivity and subendothelial thrombogenicity and less severe morphological lesions of the endothelium and vascular wall. We conclude that supplementation of the SFAED with 15% olive oil reduced vascular thrombogenicity and platelet activation in rabbits. Although the percentage of olive oil in the diet was higher than the amount in the human diet, these results may be helpful in determining the effect of olive oil in the human thrombogenic system. |
| Antitumor effects and pharmacokinetics of aclacinomycin A carried by injectable emulsions composed of vitamin E, cholesterol, and PEG-lipid Wang, J., Y. Maitani, et al. (2002), J Pharm Sci 91(4): 1128-34. Abstract: The aim of this study was to prepare injectable emulsions of aclacinomycin A (E-ACM) and evaluate its acute toxicity, antitumor effects, and pharmacokinetics. In E-ACM, the surfactants were polyethylene glycol-lipid and cholesterol, and the oil phase was a vitamin E solution of ACM. The particle size distribution and the zeta potential of E-ACM were measured by the laser light dynamic scattering method. The ACM-loading efficiency was measured by using Sephadex G50 column chromatography. The acute toxicity, antitumor effects, and pharmacokinetics of E-ACM were studied in C57BL/6 mice bearing mouse murine histiocytoma M5076 tumors. The average diameter, zeta potential, and ACM-loading efficiency of E-ACM were 123.0 +/- 1.2 nm, - 12.67 +/- 1.35 mv, and 96.3 +/- 0.3% (n = 3), respectively. When stored at 7 degrees C in the dark for 1 year, the average diameter and ACM-loading efficiency of E-ACM changed into 126.3 +/- 2.3 nm and 97.4 +/- 0.8%, respectively, whereas 6.5 +/- 0.2% ACM decomposition was observed (n = 3). The plasma areas under the biodistribution curves (AUC)(0.03-48h) of E-ACM was significantly greater than that of free ACM (F-ACM). The heart, lung, and kidney AUC(0.03-48h) of E-ACM were significantly smaller than those of F-ACM whereas the liver and spleen AUC(0.03-48h) of E-ACM were not significantly different from those of F-ACM. The tumor AUC(0.03-48h) of E-ACM was significantly greater than that of F-ACM. E-ACM had lower acute toxicity and greater potential antitumor effects than F-ACM in M5076 tumor-bearing C57BL/6 mice. E-ACM is a useful tumor-targeting drug delivery system. |
| Aortic antioxidant defence mechanisms: time-related changes in cholesterol-fed rabbits Del Boccio, G., D. Lapenna, et al. (1990), Atherosclerosis 81(2): 127-35. Abstract: In 24 rabbits fed a hyperlipidic diet (0.5% cholesterol, 5% lard and 5% peanut oil) for 10 (group A1), 30 group B1) and 60 days, (Group C1), compared to 24 control rabbits fed a standard diet for the same periods, antioxidant defence system (total superoxide dismutase, catalase, total thiol compounds selenium-dependent and selenium-independent glutathione peroxidase, glutathione reductase, glutathione transferase) and lipid peroxidation (thiobarbituric acid-reactive substances) in the aortic wall were tested. The percent of intima with grossly apparent atherosclerosis, is assessed by staining with the lipophilic dye Sudan IV, was negligible in group A1, but increased progressively in groups B1 (22.7-6.7%) and C1 (56.8-8.8%). Compared to the controls, a significant rise in superoxide dismutase activity was observed after 30 days of hyperlipidic diet, with a further marked increase at 60 days. Total thiol compounds and selenium-dependent glutathione peroxidase activity rose progressively from 10 to 30 and 60 days in cholesterol-fed rabbits. On the contrary, catalase, glutathione reductase and glutathione transferase activities significantly decreased in all experimental groups. Selenium-independent glutathione peroxidase activity was not detectable. Thiobarbituric acid-reactive substances increased about 3 times in hyperlipidemic rabbits. In conclusion, the changes in aortic antioxidant defence mechanisms and lipid peroxidation precede the massive vascular lipid infiltration in cholesterol-fed rabbits; some antioxidant mechanisms are stressed (superoxide, dismutase, glutathione peroxidase, total thiol compounds), whereas others are depressed (catalase, glutathione reductase, and glutathione transferase), thus potentially reducing or increasing vascular susceptibility to oxidative injury. |
| Aortic esterified cholesterol is not superior to total cholesterol as a measure of atherosclerosis severity in cholesterol-fed rabbits Nielsen, L. B., B. G. Nordestgaard, et al. (1993), Atherosclerosis 99(1): 133-6. |