Protein metabolism. IV. Altered protein synthesis in hosts infected with Eimeria tenella or bacteria compared to synthesis in hosts infected with intestinal nematodes

Symons, L. E.; Jones, W. O.

doi:10.1016/0014-4894(77)90077-7

Caecal infection of the chicken by Eimeria tenella, generalized bacterial infection of the guinea-pig by Yersinia pseudotuberculosis, and bacterial infection of the feet of the sheep (foot-rot) were used to test the hypotheses: that a slower rate of muscle protein synthesis is not specific to nematode infections but also occurs in unrelated diseases characterized by anorexia, and 2nd, that liver protein synthesis would not increase without loss of serum proteins. The first hypothesis was supported when the rate of incorporation of radioactively labeled L-leucine, in vivo by muscle and in vitro by isolated ribosomes, was reduced in coccidiosis and yersinosis, but the effect of foot-rot was uncertain. The rate of liver protein synthesis was unchanged in chickens with caecal haemorrhage, whereas incorporation of amino acid by membrane-bound ribosomes, which synthesize certain serum proteins, was increased in foot-rot in which there is no intestinal loss. [AS] Caecal infection of the chicken by Eimeria tenella and general infection of the guinea-pig by Yersinia pseudotuberculosis produced a slower rate of muscle protein synthesis which is therefore not specific to mammalian intestinal nematode infections. In both foot-rot and Trichostrongylus colubriformis infection in sheep, incorporation of N, but not of DNA and RNA, increased suggesting increased liver protein synthesis. This increase was not however always related to loss of serum proteins into the intestine.