Search Results
Altmann, S. W., Davis, H. R. Jr., Zhu, L. J. és mtsai: Niemann-Pick C1 Like 1 protein is critical for intestinal cholesterol absorption. Science, 2004, 303 , 1021
Abstract
The standard molar enthalpy of combustion of cholesterol was measured at constant volume. According to value of Δr U m θ(−14358.4±20.65 kJ mol−1), Δr H m θ(−14385.7 kJ mol−1) of combustion reaction and Δf H m θ(2812.9 kJ mol−1) of cholesterol were obtained from the reaction equation. The enthalpy of combustion reaction of cholesterol was also estimated by the average bond enthalpies. By design of a thermo-chemical recycle, the enthalpy of combustion of cholesterol were calculated between 283.15∼373.15 K. Besides, molar enthalpy and entropy of fusion of cholesterol was obtained by DSC technique.
Thirty-three varieties of dairy products were analysed for fat and cholesterol contents, and a high correlation (r=0.983) was found between these two compositional attributes. Cholesterol concentration was independent of processing factors such as heat-treatment of the raw material, use of starter culture, type of the starter organisms employed and whipping or flavouring of the product. The non-fat varieties of fluid, fermented and dried milks showed significantly increased cholesterol-to-fat ratios compared to the other products tested because they contained considerable amounts of small fat globules and, therefore, had a large surface area with cholesterol bound to the fat globule membranes. The results of this study may be useful when establishing dietary guidelines for the general public according to health concerns, when formulating diets for population groups with special requirements or when assessing fat and cholesterol intakes in epidemiological studies aimed at investigating the relationship between diet and health.
The objective of this paper is to investigate variability in chemical composition, total fatty acid and cholesterol content in m. longissimus dorsi (MLD) of Mangalitsa, swallow-belly (LM) and white (BM), and Swedish Landrace pigs (SL). Compared to SL, the total fat content has been 14.2% higher in BM, while it has been 10.2% higher in LM. SL fatteners contained significantly less cholesterol in MLD compared to LM and BM (−13.6 and −14.8%, P≤0.05). A higher percentage of SFA (+8.5 and +10.1%, P≤0.05) and PUFA (+8.0 and +9.4%, P≤0.05) has been established in MLD, originating from SL fatteners, compared to both Mangalitsa strains. The total MUFA content was higher in LM and BM than in SL (P≤0.05). A phenotypic correlation between protein content and ashes with water content in MLD has been positive (0.81 and 0.88), while the correlation between water content and total fats has been found to be negative (−0.99). A negative phenotypic correlation between MUFA and SFA, as well as PUFA and MUFA (−0.97 and −0.98) has been established, statistically significant at the level of P≤0.001. A positive phenotypic correlation between PUFA and SFA (0.90), statistically significant at the level of P≤0.001, has been found.
Daniels, T. F., Killinger, K. M., Michal, J. J. és mtsai: Lipoproteins, cholesterol homeostasis and cardiac health. Int. J. Biol. Sci., 2009, 5 , 474
The chemical composition, fatty acid profile, and cholesterol content of milk fat were analysed during the lactation period of thirty Iranian Ghezel sheep. They were fed dry hay for the first three months and then grazed on fresh grass to the end of lactation, along with barley and wheat middling during the whole period. Fatty acid profile analysis showed palmitic acid to be the dominant fatty acid (45.24±1.88%). During lactation C6:0, C8:0, C10:0, C12:0, and C14:0 contents decreased, while C18:0, C18:1, C18:2, and CLA increased significantly, which can be associated with the change of nutrition from hay to fresh grazing. The cholesterol content of the sheep milk reached 14.88 mg/100 ml milk or 283.43 mg/100 g fat as an average for the whole period of milking. Regression analysis showed a significant increase in cholesterol from 5.42 to 32.87 mg/100 g milk during the lactation period.
Summary
A method for determining underivatized cholesterol and its oxygen derivatives (ChlOs) in animal tissue specimens and some food has been developed using capillary gas chromatography (GC) and mass spectrometry (MS) with 5α-cholestane as the internal standard. The analysis preparation procedure for cholesterol and ChlOs consisted of lipid extraction followed by gentle saponification using 2 M KOH in ethanol. The analyzed samples were saponified overnight at room temperature in the dark with shaking. Then, free cholesterol and ChlOs were extracted using diethyl ether. The extracts were dried under argon, and the residues were redissolved in chloroform before GC-MS analysis. Cholesterol was analyzed in biological materials using the short column temperature program. The simultaneous quantification of cholesterol and its oxides in biological materials was performed using the longer column temperature program. Cholesterol was eluted faster than ChlOs. The chromatographic method that used column temperature program A can be successfully used for the simple and rapid quantification of cholesterol in biological materials, while the method using column temperature program B is more suitable for the simultaneous quantification of cholesterol and its oxides in biological materials.
The moisture, protein, fat, and ash contents of Barbus grypus muscle were 76.14, 18.85, 2.95, and 0.83%, respectively. The fatty acid composition of B. grypus showed that the amounts of saturated fatty acids (SFA) were significantly (P<0.05) higher (34.88%) in the liver compared to the muscle (30.18%). Of the SFA, the amount of palmitic acid was significantly (P<0.05) higher in the liver than that in the muscle and gonad. With regard to the monounsaturated fatty acids (MUFA), oleic acid content in the muscle (23.46%) of B. grypus was significantly (P<0.05) higher than in the liver (18.01%). The amounts of docosahexaenoic acid (C22:6 n-3, DHA), eicosatetraenoic acid (C20:4 n-3), and eicosapentaenoic acid (C20:5 n-3, EPA) were predominantly found in the muscle, liver, and gonad. The amount of cholesterol in the liver and gonad was significantly higher than in the muscle. On the other hand, significantly higher (P<0.05) retinol, D3, δ-tocopherol, and K1 vitamin values were found in the liver than in the muscle and gonad of this species.
349 Fon Tacer, K., Haugen, T. B., Baltsen, M. és mtsai: Tissue-specific transcriptional regulation of the cholesterol biosynthetic pathway leads to accumulation of testis
This study investigated the effects of administration of monosodium L-glutamate (MSG) on serum gonadotrophin-releasing hormone (GnRH), luteinising hormone (LH), testosterone and total cholesterol (TC), cauda epididymal sperm reserves (CESR) and testicular histomorphology of adult male albino rats. Eighty-four rats, randomly assigned to 7 groups of 12 rats each, were used for the study. Varying low doses (0.25, 0.50 or 1.00 g/kg body weight) of MSG were administered orally or subcutaneously at 48-h intervals for six weeks. Serum GnRH, LH, testosterone and TC, and CESR were evaluated on days 14, 28 and 42 of MSG administration. Testicular histomorphology was evaluated on day 42. The results showed that the mean serum GnRH, LH and testosterone levels, and the CESR of all the treated groups were significantly (P < 0.05) lower than those of the untreated control on days 14, 28 and 42 of MSG administration. The mean serum TC levels of all the treated groups were also significantly (P < 0.05) lower than those of the control group on days 14 and 28. No lesions were observed on sections of the testes. It was concluded that MSG administration for 14, 28 and 42 days led to significantly lower serum levels of GnRH, LH, testosterone and TC, and significantly lower CESR.
