PLASMA AND BRAIN TRYPTOPHAN CHANGES IN EXPERIMENTAL ACUTE HEPATIC FAILURE

Abstract

Abstract An experimental model for acute hepatic failure in man was obtained in pigs by hepatic devascularization. After operation, liver function was grossly impaired, movements became inco‐ordinated and coma ensued. Most animals died 5½–8½ h after operation. Plasma unesteritied fatty acid and free (but not total) tryptophan concentrations rose markedly after operation and correlated significantly with each other. Brain tryptophan concentration increased and correlated significantly with plasma free tryptophan concentration. Increased tryptophan was found in the four brain regions studied (hypothalamus, thalamus, caudate and cortex) and was associated with raised 5‐hydroxytryptamine turnover as indicated by raised 5‐hydroxyindolylacetic acid concentration. Results are discussed in relation to altered tryptophan metabolism in human hepatic coma and to investigations of the influence of plasma unesterified fatty acid and free tryptophan changes on brain tryptophan metabolism in the rat.