Lecithin-Cholesterol Acyltransferase (LCAT) Activity in Chronic Uremic Patients

2015 ◽  
pp. 179-185
Author(s):  
G. F. Guarnieri ◽  
M. Moracchiello ◽  
L. Campanacci ◽  
F. Ursini ◽  
L. Ferri ◽  
...  
Keyword(s):  
Cholesterol Acyltransferase ◽  
Lcat Activity ◽  
Lecithin Cholesterol Acyltransferase ◽  
Uremic Patients

Lecithin-cholesterol acyltransferase activity during maturation of human preovulatory follicles with different concentrations of ascorbate, a-tocopherol and nitrotyrosine

2002 ◽  
Vol 14 (1) ◽  
pp. 15 ◽  
Author(s):  
L. Cigliano ◽  
M. Balestrieri ◽  
M. S. Spagnuolo ◽  
B. Dale ◽  
P. Abrescia
Keyword(s):  
Follicular Fluid ◽  
Acyl Chain ◽  
Cholesterol Acyltransferase ◽  
Lcat Activity ◽  
Acyltransferase Activity ◽  
Lecithin Cholesterol Acyltransferase ◽  
Preovulatory Follicles ◽  
Mechanism Of Catalysis ◽  
Follicle Maturation ◽  
Follicular Fluids

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.

scholarly journals Effects of Two Hypocaloric Diets Supplemented With White Lupine or Oats on Lipid Peroxidation, Reverse Cholesterol Transport and Paraoxonase Activity in Obese Rat

2013 ◽  
Vol 2 (5) ◽  
pp. 1
Author(s):  
Fatima Z. Chabane ◽  
Sabrine Louala ◽  
Nabila Boukhari ◽  
Mounia Besbes ◽  
Douja Taleb-Senouci ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Caloric Restriction ◽  
Reverse Cholesterol Transport ◽  
Cholesterol Acyltransferase ◽  
Cholesterol Content ◽  
Pon1 Activity ◽  
Cholesterol Transport ◽  
Lcat Activity ◽  
Lecithin Cholesterol Acyltransferase ◽  
Obese Rats

<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>

Reverse cholesterol transport in hypercholesterolemic rats fed different proteins and lipids origins

2009 ◽  
Vol 39 (2) ◽  
pp. 128-141 ◽  
Author(s):  
Bouderbala Shérazède ◽  
Lamri‐Senhadji Myriem ◽  
Boualga Ahmed ◽  
Belleville Jacques ◽  
Prost Josiane ◽  
...  
Keyword(s):  
Critical Role ◽  
Cholesterol Acyltransferase ◽  
Cholesterol Transport ◽  
Dietary Proteins ◽  
Lcat Activity ◽  
Unesterified Cholesterol ◽  
Content Type ◽  
Chick Pea ◽  
Lecithin Cholesterol Acyltransferase ◽  
L Proteins

PurposeThe purpose of this paper is to determine the effects of different dietary protein and lipid origins on serum HDL2 and HDL3 compositions and lecithin: cholesterol acyltransferase (LCAT) activity in growing rats fed a 0.5 per cent cholesterol‐enriched diet with either 20 per cent casein (C), chick pea (CP) or lentil (L) proteins combined to 10 per cent olive (O) or salmon (S) oil for 28 days.Design/methodology/approachHDL2 and HDL3 separation according to Sjöblom and Eklund and LCAT activity according to Glomset and Wright.FindingsSerum total cholesterol was 1.3‐fold lower in CPS than in CPO group. HDL3 amounts were 2‐ and 1.5‐fold higher in CPO and LO groups, respectively, compared to CO group. HDL3‐unesterified cholesterol values were, respectively, 2‐ and 5‐fold lower in CPO and LO groups than in CO group, and were threefold decreased in CPS and LS groups vs CS group. HDL3‐phospholipids in LO group represented 12 and 51 per cent of the CO and CPO group values, respectively. HDL2‐triacylglycerol amounts were decreased in LO group vs CO group (−67 per cent) and in CPS and LS groups (−62 per cent) compared to CS group. HDL3‐apolipoprotein A‐I values were lower in LO group vs CO and CPO groups, and in CPS group vs CS group. However, LCAT activity was similar in all the studied groups.Originality/valueThe paper shows that when diets containing casein, chick pea or lentil proteins combined with olive or salmon oil are supplemented with cholesterol, HDL2 and HDL3 compositions are impaired despite unchanged LCAT activity. Moreover, if oils modify HDL compositions, dietary proteins play a critical role in these modifications.

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