Protein nutrition, through altered amino-acid supply, regulates the quality and quantity of animal products, and deficiencies in supply of / response to amino-acids may be a limiting factor in ruminant efficiency. The effects of amino-acid supply may be indirect, via modulation of anabolic hormonal signalling. In particular, amino-acid limitation reduces insulin-like growth factor-1 (IGF-1) - and increases IGF-1 binding protein 1 (IGFBP-1) - production by the liver, and hence modulates the sensitivity of tissues to pituitary GH as an anabolic signal (Gluckman et al, 1987). The mechanisms through which amino-acids exert these selective effects on liver protein production are not understood.

The present study sought to determine whether the effects of amino-acids on total cellular protein synthesis are sufficient to account for observed reductions in IGF-1 production in cultured ovine hepatocytes. In addition the use of two dimensional polyacrylamide gel electrophoresis (2D-PAGE) to visualise changes in translation of individual proteins caused by amino-acids in cultured ovine hepatocytes is described.