6533b82dfe1ef96bd1290899

RESEARCH PRODUCT

Cardiovascular and Endocrine Properties of L-Tryptophan in Combination with Various Diets

J. BeyerHendrik Lehnert

subject

medicine.medical_specialtyChemistryTryptophanAdrenocorticotropic hormoneTetrahydrobiopterinTryptophan hydroxylaseProlactinmedicine.anatomical_structureEndocrinologyAnterior pituitaryInternal medicinemedicineSerotoninTyrosinemedicine.drug

description

Brain serotonin neurons are intimately involved in a number of relevant physiological functions such as cardiovascular regulation, neuroendocrine output from the anterior pituitary (e.g. ACTH, prolactin), regulation of behavior (e.g. agression, sleep, locomotor and sexual behavior), mood or appetite control (Fernstrom, 1983; Lehnert et al., 1987; Spring et al., 1987; Wurtman, 1987). The synthesis of brain serotonin is dependent on the availability of the large neutral amino acid L-tryptophan that is hydroxylated to 5-L-hydroxytryptophan and subsequently decarboxylated to yield serotonin. The rate-limiting enzyme tryptophan hydroxylase has a Michaelis constant of approximately 2–3 x 10−5 M with tetrahydrobiopterin used as a cofactor (Tong and Kaufmann, 1975) and thus approximates normal brain tryptophan concentrations of about 1–5 x 10−5 M. Therefore, the enzyme is not saturated under normal circumstances and an increased availability of brain tryptophan will lead to an enhanced synthesis of brain serotonin (Fernstrom and Wurtman, 1971; Fernstrom, 1983).

yearjournalcountryeditionlanguage
1991-01-01
https://doi.org/10.1007/978-1-4684-5952-4_37