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

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.

1977 ◽  
Vol 168 (3) ◽  
pp. 571-574 ◽  
Author(s):  
P D Lotlikar ◽  
E N Dwyer ◽  
W J Baldy ◽  
J Nyce

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.


2017 ◽  
Vol 31 (1) ◽  
pp. 91-99 ◽  
Author(s):  
Kanniah Rajasekaran ◽  
Greg Ford ◽  
Kandan Sethumadhavan ◽  
Carol Carter-Wientjes ◽  
John Bland ◽  
...  

2013 ◽  
Vol 37 (2) ◽  
pp. 99-106 ◽  
Author(s):  
Geun Ho Gim ◽  
Jung Kon Kim ◽  
Hyeon Seok Kim ◽  
Mathur Nadarajan Kathiravan ◽  
Hetong Yang ◽  
...  

Author(s):  
Tereza Pavlova ◽  
Zdenek Spacil ◽  
Veronika Vidova ◽  
Filip Zlamal ◽  
Eliska Cechova ◽  
...  

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.


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 ◽  
...  

Author(s):  
J.M. Deslous-Paoli ◽  
M. Heral ◽  
M. Jousset ◽  
S. Boromthanarat ◽  
P. Goulletquer ◽  
...  

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