caa a22 4500 469119861 CHVBK 20180323133135.0 cr unu---uuuuu 170328e19920701xx s 000 0 eng 10.1007/BF02245286 doi (NATIONALLICENCE)springer-10.1007/BF02245286 Acute tryptophan depletion blocks morphine analgesia in the cold-pressor test in humans [Elektronische Daten] [Frances Abbott, Pierre Etienne, Keith Franklin, Michael Morgan, Maida Sewitch, Simon Young] The effects of depletion of the serotonin precursor,l-tryptophan, on the threshold and tolerance to cold pressor pain, and the analgesic effect of morphine (10 mg intramuscularly), were tested in a double blind trial on human volunteers. Effects on mood were also assessed using the Profile of Mood States and the Addiction Research Center Inventory (ARCI) Scales. To deplete tryptophan, subjects were fed a tryptophan-deficient amino acid mixture 4.5 h before morphine was administered. Controls received the mixture with tryptophan, which is equivalent to a nutritionally balanced protein. The tryptophan-deficient meal reduced plasma tryptophan more than 70% but had no effect on threshold or tolerance to cold pressor pain. After morphine, tolerance to cold pressor pain increased in controls. Tryptophan depletion abolished this analgesic effect. Pain threshold was not altered by morphine. In subjects with normal tryptophan, the analgesic effect of morphine was predicted by the level of plasma morphine-6-glucuronide, but not by the level of morphine. Morphine increased scores on the LSD scale of the ARCI, but had no effect on other measures of mood. Tryptophan depletion also failed to alter mood in these subjects, who had unusually low depression scores before tryptophan depletion. Springer-Verlag, 1992 Serotonin nationallicence Tryptophan nationallicence Morphine nationallicence Morphine-6-glucuronide nationallicence Analgesia nationallicence Humans nationallicence Cold pressor pain nationallicence Mood nationallicence Drug abuse nationallicence Abbott Frances Department of Psychiatry, McGill University, 1033 Pine Avenue West, H3A 1A1, Montreal, Quebec, Canada aut Etienne Pierre Department of Psychiatry, McGill University, 1033 Pine Avenue West, H3A 1A1, Montreal, Quebec, Canada aut Franklin Keith Department of Psychology, McGill University, 1033 Pine Avenue West, H3A 1A1, Montreal, Quebec, Canada aut Morgan Michael Department of Psychology, McGill University, 1033 Pine Avenue West, H3A 1A1, Montreal, Quebec, Canada aut Sewitch Maida School of Nursing, McGill University, 1033 Pine Avenue West, H3A 1A1, Montreal, Quebec, Canada aut Young Simon Department of Psychiatry, McGill University, 1033 Pine Avenue West, H3A 1A1, Montreal, Quebec, Canada aut Psychopharmacology Springer-Verlag 108/1-2(1992-07-01), 60-66 0033-3158 108:1-2<60 1992 108 213 https://doi.org/10.1007/BF02245286 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02245286 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Abbott Frances Department of Psychiatry, McGill University, 1033 Pine Avenue West, H3A 1A1, Montreal, Quebec, Canada aut NATIONALLICENCE 700 1- Etienne Pierre Department of Psychiatry, McGill University, 1033 Pine Avenue West, H3A 1A1, Montreal, Quebec, Canada aut NATIONALLICENCE 700 1- Franklin Keith Department of Psychology, McGill University, 1033 Pine Avenue West, H3A 1A1, Montreal, Quebec, Canada aut NATIONALLICENCE 700 1- Morgan Michael Department of Psychology, McGill University, 1033 Pine Avenue West, H3A 1A1, Montreal, Quebec, Canada aut NATIONALLICENCE 700 1- Sewitch Maida School of Nursing, McGill University, 1033 Pine Avenue West, H3A 1A1, Montreal, Quebec, Canada aut NATIONALLICENCE 700 1- Young Simon Department of Psychiatry, McGill University, 1033 Pine Avenue West, H3A 1A1, Montreal, Quebec, Canada aut NATIONALLICENCE 773 0- Psychopharmacology Springer-Verlag 108/1-2(1992-07-01), 60-66 0033-3158 108:1-2<60 1992 108 213 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer