Skatole increases expression of detoxification genes in the ovine liver

摘要

Skatole (3-methylindole) is a toxic xenobiotic produced during rumen bacterial degradation of tryptophan. Skatole contributes to the unique flavour palate known as pastoral flavour (characterised by 'sheepy' or 'grassy' odours) that differentiates meat and milk products of pasture-fed ruminants from those finished under grain-based production systems. Accumulation in milk and meat fat occurs when skatole absorbed from the reticulorumen exceeds the detoxification capacity of the liver. These conditions arise when ruminants are fed fresh forages with high rumen degradable protein (RDP) content. We hypothesise that under conditions of minimal endogenous skatole production (low dietary RDP) a continuous rumen infusion of skatole will elevate absorptionand modify liver metabolism of skatole within 72 h. This hypothesis is supported by a 50% reduction in peripheral plasma skatole concentration between 16 and 72 h of continuous skatole infusion (Deighton et al, 2006). Therefore, cDNAmicroarray analysis was used to identify differential gene expression in the ovine liver in response to a 72 h skatole exposure administered via rumen infusion.