Toxicity and intracellular accumulation of bile acids in sandwich-cultured rat hepatocytes: Role of glycine conjugates
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- 作者：Sagnik Chatterjee ; Ingrid T.G.W. Bijsmans ; Saskia W.C. van Mil ; Patrick Augustijns ; Pieter Annaert
- 关键词：BAs ; bile acids ; BAAT ; bile acid CoA ; amino acid N-acyltransferase ; BEI ; biliary excretion index ; BSEP/Bsep ; bile salt export pump (human/rat) ; DMSO ; dimethyl sulfoxide ; CDCA ; chenodeoxycholic acid ; CA ; cholic acid ; FBS ; Fetal Bovine Serum GCDCA ; glycochenodeoxycholic acid ; GDCA ; glycodeoxycholic acid ; HBSS ; Hanks&rsquo ; Balanced Salt Solution ; HEPES ; 4-(2-hydroxyethyl)-1-piperazine ethanesulfonic acid ; NOAEL ; no observed adverse effect level ; NTCP/Ntcp ; sodium taurocholate cotransporting polype
- 刊名：Toxicology in Vitro
- 出版年：March, 2014
- 年：2014
- 卷：28
- 期：2
- 页码：218-230
- 全文大小：2967 K
文摘
Excessive intrahepatic accumulation of bile acids (BAs) is a key mechanism underlying cholestasis. The aim of this study was to quantitatively explore the relationship between cytotoxicity of BAs and their intracellular accumulation in sandwich-cultured rat hepatocytes (SCRH). Following exposure of SCRH (on day-1 after seeding) to various BAs for 24 h, glycine-conjugated BAs were most potent in exerting toxicity. Moreover, unconjugated BAs showed significantly higher toxicity in day-1 compared to day-3 SCRH. When day-1/-3 SCRH were exposed (0.5-4 h) to 5-100 渭M (C)DCA, intracellular levels of unconjugated (C)DCA were similar, while intracellular levels of glycine conjugates were up to 4-fold lower in day-3 compared to day-1 SCRH. Sinusoidal efflux was by far the predominant efflux pathway of conjugated BAs both in day-1 and day-3 SCRH, while canalicular BA efflux showed substantial interbatch variability. After 4 h exposure to (C)DCA, intracellular glycine conjugate levels were at least 10-fold higher than taurine conjugate levels. Taken together, reduced BA conjugate formation in day-3 SCRH results in lower intracellular glycine conjugate concentrations, explaining decreased toxicity of (C)DCA in day-3 versus day-1 SCRH. Our data provide for the first time a direct link between BA toxicity and glycine conjugate exposure in SCRH.