Open AccessEffects of Various Drugs on Serum Free and Total Tryptophan Levels and Brain Tryptophan Metabolism in Rats
Author(s) -
Hisato Iwata,
Hiroshi Okamoto,
Setsuko Koh
Publication year - 1975
Publication title -
japanese journal of pharmacology/japanese journal of pharmacology
Language(s) - English
Resource type - Journals
eISSN - 1347-3506
pISSN - 0021-5198
DOI - 10.1254/jjp.25.303
Subject(s) - pargyline , chemistry , sodium salicylate , monoamine oxidase inhibitor , tryptophan , hypothermia , serotonin , pharmacology , in vivo , monoamine oxidase , medicine , endocrinology , biochemistry , enzyme , biology , receptor , microbiology and biotechnology , organic chemistry , amino acid
Various drugs known to bind to serum albumin were examined to determine whether or not they influenced the level of free tryptophan in serum in vitro and in vivo. Possible relationships between the serum free tryptophan level and serotonin (5-HT) synthesis in the brain and the hypothermic effects of these drugs were investigated. Of the drugs examined, sodium salicylate, sodium benzoate and indomethacin caused a significant increase in the concentration of serum free tryptophan and stimulated the synthesis of 5-HT in the brain. Hypothermia induced by salicylate and indomethacin was potentiated by pretreatment with pargyline, a monoamine oxidase inhibitor. Administration of benzoate did not cause any change in body temperature, but after pargyline a hypothermia did occur. However, pretreatment with parachlorophenylalanine, an inhibitor of 5-HT synthesis, did not influence the hypothermia induced by salicylate and indomethacin. Relationship between the hypothermic effect and the increase of 5-HT synthesis in the brain after a large dose of salicylate and indomethacin is discussed.