scholarly journals Phospholipid requirement for 2-acetamidofluorene N-and ring-hydroxylation by hamster liver microsomal cytochrome P-450 enzyme system

1977 ◽  
Vol 168 (3) ◽  
pp. 571-574 ◽  
Author(s):  
P D Lotlikar ◽  
E N Dwyer ◽  
W J Baldy ◽  
J Nyce
Keyword(s):  
Total Lipid ◽  
Lipid Content ◽  
Microsomal Fraction ◽  
Enzyme System ◽  
Total Lipid Content ◽  
Appreciable Effect ◽  
Microsomal Cytochrome ◽  
Lower Capacity ◽  
Cytochrome P 450 ◽  
Ring Hydroxylation

A phospholipid requirement of 2-acetamidofluorene N- and ring-hydroxylation was investigated with partially delipidated microsomal fraction from livers of 3-methylcholanthrene-pretreated hamsters. Butan-1-ol extraction of microsomal fraction removed 90% of the total lipid content without any appreciable effect on microsomal proteins. Such extracted microsomal fractions had much lower capacity to N- and ring-hydroxylate 2-acetamidofluorene: 25 and 44% of control respectively. Addition of butan-1-ol-extracted total lipid restored both oxidations to some extent, whereas addition of phosphatidylcholine fraction restored both oxidations almost completely. Addition of synthetic phospholipid, dilauroyl phosphatidylcholine, restored both oxidations to a large extent, whereas synthetic dipalmitoyl or distearoyl phosphatidylcholine was ineffective in restoring these oxidations.

scholarly journals Phospholipid requirement for dimethylnitrosamine demethylation by hamster hepatic microsomal cytochrome P-450 enzyme system

1976 ◽  
Vol 160 (2) ◽  
pp. 401-404 ◽  
Author(s):  
P D Lotlikar ◽  
W J Baldy ◽  
J Nyce ◽  
E N Dwyer
Keyword(s):  
Catalytic Activity ◽  
Total Lipid ◽  
Lipid Content ◽  
Enzyme System ◽  
Total Phospholipid ◽  
Total Lipid Content ◽  
Microsomal Cytochrome ◽  
Freeze Dried ◽  
Reconstituted System ◽  
Cytochrome P 450

Extraction with butan-1-ol of freeze-dried microsomal fractions from livers of 3-methyl-cholarthrene-pre-treated hamsters removed about 90% of the total lipid content, but the lipid remaining proved sufficient for the cytochrome P-450 enzyme system to retain about 15-40% of its original catalytic activity for dimethylnitrosamine demethylation. Addition of butan-1-ol-extracted total phospholipid or phosphatidylcholine could not restore any activity, whereas the addition of the synthetic phospholipid dilauroyl phosphatidylcholine was able to restore almost complete activity. Synthetic dipalmitoyl or distearoyl phosphatidylcholine was ineffective in restoring the activity in this reconstituted system.

Aspergillus flavusgrowth and aflatoxin production as influenced by total lipid content during growth and development of cottonseed

2017 ◽  
Vol 31 (1) ◽  
pp. 91-99 ◽  
Author(s):  
Kanniah Rajasekaran ◽  
Greg Ford ◽  
Kandan Sethumadhavan ◽  
Carol Carter-Wientjes ◽  
John Bland ◽  
...  
Keyword(s):  
Total Lipid ◽  
Lipid Content ◽  
Growth And Development ◽  
Total Lipid Content ◽  
Aflatoxin Production

Comparison of biomass production and total lipid content of freshwater green microalgae cultivated under various culture conditions

2013 ◽  
Vol 37 (2) ◽  
pp. 99-106 ◽  
Author(s):  
Geun Ho Gim ◽  
Jung Kon Kim ◽  
Hyeon Seok Kim ◽  
Mathur Nadarajan Kathiravan ◽  
Hetong Yang ◽  
...  
Keyword(s):  
Biomass Production ◽  
Total Lipid ◽  
Lipid Content ◽  
Total Lipid Content ◽  
Culture Conditions ◽  
Green Microalgae

scholarly journals Adipophilin and Perilipin 3 Correlate with Total Lipid Content in Human Breast Milk

2018 ◽  
Author(s):  
Tereza Pavlova ◽  
Zdenek Spacil ◽  
Veronika Vidova ◽  
Filip Zlamal ◽  
Eliska Cechova ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Breast Milk ◽  
Total Lipid ◽  
Lipid Content ◽  
Gravimetric Method ◽  
Total Lipid Content ◽  
Milk Lipid ◽  
Human Breast Milk ◽  
Human Breast

Objective: Lipids are secreted into milk as bilayer-coated structures: milk lipid globules (MLGs). Adipophilin (ADRP) and perilipin 3 (TIP47) are associated with MLGs in human breast milk; however, the role of these proteins in milk lipid secretion is not fully understood. The aim of the study was to investigate levels of ADRP, TIP47 and total lipid content in human breast milk, their mutual correlations and dynamics during lactation. Research Methods & Procedures: Milk samples from 22 healthy lactating women (Caucasian, Central European) were collected at five time points during lactation (1–3, 12–14, 29–30, 88–90 and 178–180 days postpartum). Mass spectrometry-based method was used for quantification of ADRP and TIP47 in the samples. The gravimetric method was used to determine milk total lipid content. Results: We observed distinctive trends in ADRP, TIP47 levels and lipid content in human breast milk during the first 6 months of lactation. We also found a significant association between lipid content and ADRP, lipid content and TIP47, and ADRP and TIP47 concentrations in breast milk at all sampling points. Moreover, we derived an equation for estimating the mean lipid content of milk based on ADRP concentration in human breast milk. Conclusions: A mass spectrometry-based method was developed for quantifying ADRP and TIP47 in human breast milk. Strong mutual correlations were found between ADRP, TIP47 and total lipid content in human breast milk.

scholarly journals Characteristics of the rat liver microsomal enzyme system converting cholecalciferol into 25-hydroxycholecalciferol. Evidence for the participation of cytochrome p-450

1979 ◽  
Vol 184 (3) ◽  
pp. 491-499 ◽  
Author(s):  
T C Madhok ◽  
H F DeLuca
Keyword(s):  
Vitamin D ◽  
White Light ◽  
Microsomal Fraction ◽  
Enzyme System ◽  
Initial Reaction ◽  
Microsomal Enzyme ◽  
Reaction Velocity ◽  
Calcium And Phosphorus ◽  
Cytochrome P 450 ◽  
25 Hydroxycholecalciferol

Properties of the rat hepatic cholecalciferol 25-hydroxylase have been studied. An assay system has been developed in which 25-hydroxycholecalciferol production is linear for at least 2h in both homogenates and microsomal fraction. Furthermore, the initial reaction velocity is linearly related to the amount of liver tissue or microsomal fraction. This enzyme system also metabolizes an analogue of cholecalciferol, namely dihydrotachysterol 3, into 25-hydroxydihydrotachysterol 3. The 25-hydroxylase is in the microsomal fraction and not in mitochondria. It has a Km of 44 nM for cholecalciferol and 360 nM for dihydrotachysterol 3. Its activity is not altered by dietary concentrations of calcium and phosphorus. Vitamin D-deficient rats have higher activities of the hepatic 25-hydroxylase than those receiving 25 ng of cholecalciferol daily. The 25-hydroxylase is inhibited by metyrapone. An atmosphere of CO/O2 (9:1, v/v) inhibits the reaction by 87%. This inhibition is partially reversed by white light. Additionally, cholecalciferol and 25-hydroxycholecalciferol competitively inhibit aminopyrine demethylase. These results support the idea that the cholecalciferol 25-hydroxylase is a cytochrome P-450-dependent mono-oxygenase.

scholarly journals Intramyocellular Lipid Droplet Size Rather Than Total Lipid Content is Related to Insulin Sensitivity After 8 Weeks of Overfeeding

Obesity ◽  
2017 ◽  
Vol 25 (12) ◽  
pp. 2079-2087 ◽  
Author(s):  
Jeffrey D. Covington ◽  
Darcy L. Johannsen ◽  
Paul M. Coen ◽  
David H. Burk ◽  
Diana N. Obanda ◽  
...  
Keyword(s):  
Insulin Sensitivity ◽  
Droplet Size ◽  
Lipid Droplet ◽  
Total Lipid ◽  
Lipid Content ◽  
Total Lipid Content ◽  
Intramyocellular Lipid ◽  
Lipid Droplet Size
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