Send to

Choose Destination
See comment in PubMed Commons below
Experientia. 1992 May 15;48(5):482-6.

Abnormal lipid composition of microsomes from cirrhotic rat liver--does it contribute to decreased microsomal function?

Author information

Department of Clinical Pharmacology, University of Bern, Switzerland.


We determined to what extent a change in the lipid composition of the smooth endoplasmic reticulum contributes to altered microsomal function in cirrhosis. Rats were rendered cirrhotic either by chronic exposure to phenobarbital/CCl4 (MCIR) or by bile duct ligation (BCIR). Microsomal function was tested in vivo by the aminopyrine breath test (ABT), then microsomes were prepared and their phospholipid and cholesterol composition analysed. ABT was reduced by 35 and 41% in BCIR and MCIR, respectively. Cholesterol in microsomes was increased in both cirrhotic groups. (BCIR + 154%, MCIR + 75%) while total phospholipid content was not affected. As shown in other membrane systems, the phospholipid/cholesterol (PL/XOL) ratio showed an excellent inverse correlation with fluorescence anisotropy determined by diphenylhexatriene fluorescence polarization (r = -0.896). The PL/XOL ratio was significantly correlated with aminopyrine N-demethylation in vivo (r = 0.649). Alterations in the composition of phospholipid groups (an increase in sphingomyelin in both cirrhotic groups, and a decrease in phosphatidylcholine and an increase in phosphatidylethanolamine in BCIR) also contributed to increased membrane rigidity. We conclude that altered membrane fluidity contributes to diminished microsomal function but that other factors must also be involved since the PL/XOL ratio explained only 42% of the variance in aminopyrine N-demethylation.

[Indexed for MEDLINE]
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Loading ...
    Support Center