1: Inflamm Res. 2005 Mar;54(3):106-12. 

Insight into the involvement of Kupffer cell-derived mediators in the
hepatoprotective effect of glycine upon inflammation: study on rat precision-cut
liver slices.

Neyrinck AM, Margagliotti S, Delzenne NM.

Unit of Pharmacokinetics, Metabolism, Nutrition and Toxicology, School of
Pharmacy, Universite Catholique de Louvain, 73 avenue Mounier, 1200 Brussels,
Belgium.

OBJECTIVE AND DESIGN: To investigate the role of inflammatory mediators in the
hepatoprotective effect of glycine against lipopolysaccharide (LPS)-induced
liver injury in rats. MATERIAL OR SUBJECTS: Male Wistar rats were used (N = 4 or
5 per group). Precision-cut liver slices (PCLS) were prepared for in vitro
studies. TREATMENT: Glycine (10 mM) and LPS (10 mug/ml) were added to the
incubation medium of PCLS obtained 3 h after LPS intraperitoneal (i. p.)
administration (10 mg/kg) or saline injection to rats. Glycine effects were also
investigated in vivo by treating rats with a diet containing glycine (5%) during
3 days. METHODS: Tissue injury was assessed by measuring adenosine triphosphate
(ATP) and glycogen contents of liver tissue as well as by measuring aspartate
aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase
(LDH) activity in the medium (in vitro) or in the serum (in vivo). Tumor
necrosis factor-alpha (TNF-alpha), prostaglandin E(2)(PGE(2)) and NOx
(reflecting nitric oxide production) were measured in the incubation medium or
in the serum. Histological detection of both ED-2 and peroxidase activity were
used as Kupffer cell markers. Student t test or two-way ANOVA were used for
statistic analysis. RESULTS: Glycine added to the culture medium increased both
ATP and glycogen contents of PCLS from LPS-treated rats, reduced the production
of TNF-alpha and NOx whereas PGE(2) secretion by PCLS increased. In contrast to
the in vitro effect of glycine, we observed that a glycine-enriched diet
decreased PGE(2) secretion in the serum after LPS challenge. CONCLUSION: The
effect of glycine on LPS-induced mediator secretion is different considering in
vitro or in vivo situations. Interestingly, glycine in vitro is able to prevent
energy status depletion of PCLS occurring upon inflammation, a phenomenon
probably linked to change in inflammatory mediator secretion pattern by hepatic
immune cells, namely Kupffer cells.

PMID: 15883743 [PubMed - in process]