Subclinical infection with the nematode Trichostrongylus colubriformis increases gastrointestinal tract leucine metabolism and reduces availability of leucine for other tissues.

摘要: Gastrointestinal (GI) tract leucine metabolism was measured in 6- to 9-mo-old lambs subjected trickle infection with Trichostrongylus colubriformis larvae and separate animals that were not infected. Animals prepared a jejunal catheter indwelling catheters into the aorta portal- (PDV) mesenteric- (MDV) drained viscera infused simultaneously [1-13C] [5,5,5-2H3] determine GI sequestration of from arterial luminal amino acid pools by tracer tracee arteriovenous concentration differences. Leucine oxidative losses net fluxes also determined across tract. Infection had no detectable effect on whole-body flux, but it increased total 24% (P<.05) 22 41% (P<.01). Net PDV decreased 20 32% during infection. The did alter either proportion precursor used derived pool (.84 .88) or proportional digesta-derived "first pass" absorptive (.12 .18). These findings help elucidate metabolic basis for reduced growth rates nitrogen retention observed when are subclinical nematode