Effect of dietary fatty acid manipulation upon the inducibility of hepatic tyrosine aminotransferase by cortisol

The present study clearly shows that, by feeding rats a semi-synthetic diet of known composition enriched with fatty acids of varying degrees of saturation, the inducibility of the hepatic cytosolic enzyme tyrosine aminotransferase by cortisol is markedly altered. In animals fed a diet enriched with saturated fatty acids (as coconut oil), cortisol, injected intraperitoneally, showed a much lower ability to induce tyrosine amino-transferase synthesis than in animals fed a diet enriched with polyunsaturated fatty acids (as safflower oil). Enzyme synthesis in response to cortisol injection in animals fed a diet rich in corn oil showed an intermediate response relative to that in the animals fed either coconut oil or safflower oil. Potential mechanisms for this phenomenon are discussed.