Mechanism of the suppression against D-galactosamine-induced hepatic injury by dietary amino acids in rats.
To elucidate the mechanism by which dietary amino acids suppress the D-galactosamine (D-GalN)-induced hepatitis, we examined the involvement of Kupffer cells, tumor necrosis factor-alpha (TNF-alpha) and apoptosis in the mechanism. In experiment 1, the rats were fed with 10% L-glutamine or 5% glycine diet injected with D-GalN with or without gadolinium chloride (GdCl3)-pretreatment. The results indicated that these amino acids suppressed the D-GalN-induced elevation of serum transaminase activities, irrespective of GdCl3-pretreatment. In experiment 2, rats were fed with 10% of L-glutamine, L-serine, L-alanine or L-glutamic acid diets injected with D-GalN. The results demonstrated that all these amino acids suppressed the D-GalN-induced elevation of serum transaminase activities, but that serum TNF-alpha concentrations and hepatic caspase-3 activities in the rats were not appreciably changed. In conclusion, the suppressive effects of amino acids on D-GalN-induced hepatitis were suggested not to be always mediated by the inhibition of Kupffer cells --> TNF-alpha --> apoptosis pathway.
Komano
Torai
T
Laboratory of Food and Nutrition, Graduate School of Science and Technology, Chiba University, 648 Matsudo, Matsudoshi, 271-8510 Chiba, Japan. trykomano@graduate.chiba-u.jp
Yokoyama Funakoshi
Reiko
R
Egashira
Yukari
Y
Sanada
Hiroo
H
D000410:Alanine Transaminase / Q000378:metabolism; D000596:Amino Acids / Q000008:administration & dosage*; D000818:Animals; D001219:Aspartate Aminotransferases / Q000378:metabolism; D056486:Chemical and Drug Induced Liver Injury / Q000178:diet therapy*; D004032:Diet; D005688:Galactosamine / Q000494:pharmacology*; D019791:Guanidine / Q000494:pharmacology; D006801:Humans; D008099:Liver / Q000187:drug effects*; D008297:Male; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D000637:Transaminases / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
D000596:Amino Acids; D014409:Tumor Necrosis Factor-alpha; D005688:Galactosamine; D000637:Transaminases; D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase; D019791:Guanidine