Article date: December 1961
By: G. BERTACCINI, M. B. NOBILI in Volume 17, Issue 3, pages 519-525
Oral administration of l‐tryptophan to rats produced two main biochemical and pharmacological effects: a marked increase in urinary 5‐hydroxyindoleacetic acid excretion, and a significant reduction in the urine flow after a water load. Urinary 5‐hydroxyindoleacetic acid excretion reached its maximum 2 to 6 hr after the administration of tryptophan, and it increased with the dose of the amino acid. Antidiuresis was seen after the administration of l‐tryptophan, 200 mg/kg, or more. The effect appeared promptly and it was roughly proportional to the dose of the amino acid administered. Both antidiuretic effect and increase in urinary 5‐hydroxyindoleacetic acid excretion were more intense after oral than after parenteral administration of l‐tryptophan. d‐Tryptophan, in oral doses up to 1,000 mg/kg, produced neither an increase in urinary 5‐hydroxyindoleacetic acid nor a reduction of diuresis. Available evidence suggests that reduction of urine flow is a consequence of biosynthesis and release of 5‐hydroxytryptamine by the gastrointestinal mucosa. Tryptamine produced by direct decarboxylation of l‐tryptophan does not seem to play any important role.
DOI: 10.1111/j.1476-5381.1961.tb01138.x
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