| Due to the lack of a complete urea cycle, uricotelic species, such as broilers, are not able to synthesize de novo arginine (Arg), thus depending exclusively on dietary Arg. High levels of dietary lysine (Lys) increase the demand for Arg because of the antagonistic relationship between these amino acids. The Arg-Lys antagonism promotes an expressive increase in the renal Arg activity and consequently induces the degradation of Arg and the decrease in the activity of glycine amidinotransferase, an enzyme that uses Arg in the synthesis of muscle creatin. Arg is considered an important modulator of immunological and physiological processes. The degradation of Arg produces ornithine, a precursor of polyamines that are key to cell division, DNA synthesis, and... |
