Meeting Abstract

S6.2  Monday, Jan. 5  Genetic links? Comparing metabolizing enzymes and efflux transporters in domestic animals FINK-GREMMELS, J; Utrecht University, Utrecht, The Netherlands J.Fink@uu.nl

Domestication of large herbivorous mammals has turned a significant part of the world into monocultures of selected monocotyledonous plant species. The basis for selection of these plant species was their nutritional value and the absence of toxic secondary plant metabolites. Several of these secondary plant metabolites, however, fulfill an important role in the mammalian organism as determinants of the gastro-intestinal flora, as natural inducers of protective efflux transporters (ABC transporters) and detoxifying enzymes. Efflux transporters and biotransformation enzymes are highly conserved and expressed in virtually all prokaryotic and eukaryotic organisms. They are closely linked to essential physiological functions including for example the inactivation of endogenous signaling molecules such as hormones and neurotransmitters, thereby fulfilling an indispensable role in the homeostasis. At the same time they are an essential part of the innate defense system against exposure to toxic substances. Both systems reflect species-specific adaptive traits and dietary preferences in the given habitat, resulting in unexpected differences in the expression pattern of transporters and enzymes in apparently related animal species, such as for example the suborder ruminants. Various lines of evidence suggest that in the absence of challenge exerted by diverse secondary plant metabolites in herbivores reduces the competence to cope with accidental exposures to natural toxins, environmental pollutants and even therapeutic agents. At the same time the strategic use of plant extracts or formulations is increasingly recognized as a therapeutic principle to regain homeostasis and to improve the overall resistance of animals to environmental challenges.