Put the body on offense.
September 07, 2010: Spring DAN! Conference…
Polyenylphosphatidylcholine Corrects the Alcohol-Induced Hepatic Oxidative Stress by Restoring S-Adenosylmethionine (2006-04-10) [PDF]
Author: Semyon I. Aleynik and Charles S. Lieber
In chronic alcoholic liver disease (ALD), the synthesis of
S-adenosylmethionine (SAMe) is significantly impaired
(Horowitz et al., 1981; Barak and Beckenhauer, 1988; Martin-
Duce et al., 1988; Lieber et al., 1990), but it is not known
whether this occurs already at the early fatty liver stage. ALD
is characterized by the excessive generation of free radicals
contributing to oxidative stress, resulting in a decrease of hepatic
reduced glutathione (GSH), a major intracellular antioxidant
(Shaw et al., 1981; Jewell et al., 1986). Synthesis of GSH de
novo includes cysteine as the rate-limiting amino acid, and
SAMe provides cysteine via a transsulfuration pathway,
serving as GSH's ultimate precursor (Fernandez-Checa et al.,
1990). Chronic alcohol consumption also leads to the depletion
of hepatic SAMe in experimental animals (Lieber et al., 1990;
Barak et al., 1993) but, at early stages of ALD, data are controversial
(Barak et al., 1987). The depletion of SAMe in ALD
could result either from decreased formation, e.g. associated
with impairment of methionine adenosyltransferase (MAT)
(EC 2.5.1.6), also called SAMe-synthetase, as observed in
patients with cirrhosis (Martin-Duce et al., 1988), or from
increased SAMe consumption for transsulphuration (e.g. GSH
synthesis) or for various transmethylations.
A mixture of polyenylphosphatidylcholines (PPC) corrects
the oxidative stress and the hepatic GSH depletion resulting
from long-term alcohol consumption in non-human primates
(Lieber et al., 1997) and at earlier stages of ALD in rats
(Aleynik et al., 2000), but whether PPC affects hepatic levels
of SAMe remains unknown. In the present study we explored
a rat model of alcohol-induced fatty liver to answer these
questions.
To read the entire study you can click on the pdf link above, or cut and paste the web link below into a new browser.
http://alcalc.oxfordjournals.org/cgi/reprint/38/3/208
