title: Subchronic treatment with amino acid mixture of L-lysine and L-arginine modifies neuroendocrine activation during psychosocial stress in subjects with high trait anxiety.
abstract: The aim of the present study was to evaluate possible modulatory effect of the treatment with L-lysine and L-arginine on neuroendocrine activation during psychosocial stress in healthy subjects with relatively high trait anxiety in a randomized, double blind placebo controlled trial. In 29 healthy subjects at the upper limit of the normal range of a trait anxiety scale, a mixture of L-lysine and L-arginine (3 g each/day) was administered for 10 days followed by exposure to a psychosocial stress procedure based on public speech. Hormone levels, cardiovascular activation and skin conductance were measured. Amino acid treatment resulted in enhanced adrenocorticotropic hormone, cortisol, adrenaline and noradrenaline levels and galvanic skin responses during stress compared to those in placebo-treated group. Increases in the heart rate and blood pressure in response to public speaking task were not influenced by amino acid treatment. Results of the present study support the hypothesis that L-lysine in combination with L-arginine, which may induce anxiolytic effects, modify hormonal responses during psychosocial stress in humans. Such action may represent a normalization of hormone levels to the pattern observed previously in subjects with low trait anxiety.
authors.affiliation: Laboratory of Pharmacological Neuroendocrinology, Institute of Experimental Endocrinology, Slovak Academy of Sciences, Bratislava, Slovakia. ueenjezo@savba.sk
authors.forename: Daniela
authors.initials: D
authors.lastname: Jezova
authors.forename: Aikaterini
authors.initials: A
authors.lastname: Makatsori
authors.forename: Miro
authors.initials: M
authors.lastname: Smriga
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Morinaga
authors.forename: Roman
authors.initials: R
authors.lastname: Duncko
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000097:blood; D000328:Adult; D001007:Anxiety / Q000188:drug therapy*; D001120:Arginine / Q000008:administration & dosage*; D001794:Blood Pressure / Q000187:drug effects; D004311:Double-Blind Method; D004837:Epinephrine / Q000097:blood; D005712:Galvanic Skin Response; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D006854:Hydrocortisone / Q000032:analysis / Q000097:blood; D008239:Lysine / Q000008:administration & dosage*; D008297:Male; D009490:Neurosecretory Systems / Q000187:drug effects* / Q000503:physiopathology*; D009638:Norepinephrine / Q000097:blood; D010919:Placebos; D012463:Saliva / Q000737:chemistry; D013060:Speech; D013315:Stress, Psychological / Q000503:physiopathology*
chemical_list: D010919:Placebos; D000324:Adrenocorticotropic Hormone; D001120:Arginine; D008239:Lysine; D006854:Hydrocortisone; D009638:Norepinephrine; D004837:Epinephrine