scholarly journals Effect of voluntary exercise and dietary protein levels on serum lipoprotein distributions and lecithin: cholesterol acyltransferase (LCAT) activity of mice.

1980 ◽  
Vol 26 (1) ◽  
pp. 59-69 ◽  
Author(s):  
Masanori YASHIRO ◽  
Shuichi KIMURA
2002 ◽  
Vol 14 (1) ◽  
pp. 15 ◽  
Author(s):  
L. Cigliano ◽  
M. Balestrieri ◽  
M. S. Spagnuolo ◽  
B. Dale ◽  
P. Abrescia

The enzyme lecithin–cholesterol acyltransferase (LCAT) transfers an acyl chain from lecithin to cholesterol or oestradiol, thus playing a crucial role in reverse cholesterol transport and follicular synthesis of potent long-lived oestrogens. The mechanism of catalysis is biphasic, as it is based on a phospholipase and an esterifying activity. Sulfhydryl groups were previously reported to be required for the esterification step. Lecithin–cholesterol acyltransferase has previously been shown to be inhibited by thiol oxidants such as peroxynitrite. Peroxynitrite also converts tyrosine to nitrotyrosines. In the present study, high levels of nitrotyrosine associated with low LCAT activity, and vice versa, were found in human preovulatory follicular fluids. Follicular fluids were also analysed for oestradiol (E) and progesterone (P) concentrations. The E/P ratio, which decreases as ovulation approaches, was used to evaluate the maturation status of each follicle. Enzyme activity was negatively correlated with the E/P ratio. Ascorbate (Asc) and α-tocopherol (Toc) were titrated in follicular fluid and plasma to evaluate their accumulation or consumption in the follicle. High LCAT activity was found in follicular fluids where Asc and Toc had accumulated, whereas lower activity was associated with Asc and Toc consumption. The consumption of both antioxidants was positively correlated with the E/P ratio. The results suggest that as follicle maturation progresses, Toc and Asc concentrations increase in follicular fluid, thus protecting LCAT from oxidative damage and loss of activity.


2013 ◽  
Vol 2 (5) ◽  
pp. 1
Author(s):  
Fatima Z. Chabane ◽  
Sabrine Louala ◽  
Nabila Boukhari ◽  
Mounia Besbes ◽  
Douja Taleb-Senouci ◽  
...  

<p>The purpose of this study was to compare the effects of two hypocaloric diets supplemented with legume or cereal on hyperglycemia, dyslipidemia, serum HDL<sub>2</sub> and HDL<sub>3</sub> composition, lipid peroxidation, and lecithin-cholesterol acyltransferase (LCAT) and paraoxonase (PON1) activities in obese rats. Obesity was induced by feeding a high-fat-diet during 3 months. At 400 ± 20 g, the obese rats were divided into three groups (n = 8): two groups were submitted for 28 days to a caloric restriction (CR) at 0.9 MJ supplemented with lupine (CR–Lupine group) or oats (CR–Oats group). The third group was fed a caloric restricted diet without supplementation (CR group). At day 28, glycemia was lower (-21%) in the CR–Oats than the CR group. CR–Oats diet reduced total cholesterol content (-13%) when compared to lupine supplementation. In contrast, CR–Lupine diet decreased serum triacylglycerols by 22% and 15% respectively <em>versus</em> CR–Oats and CR diets. Lipoproteins lipid peroxidation was significantly lower in CR–Lupine and CR–Oats when compared to the CR diet. Serum PON1 activity was increased in CR–Lupine (+88%) and CR–Oats (+82%) groups compared to CR group. Furthermore, LCAT activity was enhanced in CR– Lupine (+23% and +26%, respectively) <em>versus</em> CR and CR–Oats groups. In obese rats, caloric restriction supplemented with lupine compared to oats supplementation has beneficial effect on hypertriglyceridemia and improves reverse cholesterol transport by enhancing LCAT activity leading to anti–atherogenic effects. This effect is partially reinforced by the high HDL PON1 activity which protects it from oxidation.</p>


2015 ◽  
pp. 179-185
Author(s):  
G. F. Guarnieri ◽  
M. Moracchiello ◽  
L. Campanacci ◽  
F. Ursini ◽  
L. Ferri ◽  
...  

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