EFFECT OF TYROSINE ON COGNITIVE FUNCTION AND BLOOD-PRESSURE UNDER STRESS

The effects of tyrosine on mood, performance, heart rate and blood pre ssure of 16 healthy young subjects were assessed. Subjects were tested on two separate days, one test session after ingestion of 100 mg/kg t yrosine and the other test session after placebo, in random order. Whi le performing a number of stress sensitive tasks, subjects were expose d to a stressor consisting of 90 dB noise. Tyrosine was found to impro ve the performance on two cognitive tasks, which were performed 1 h af ter administration of the medication and which could be characterized as highly sensitive to stress. In addition, tyrosine decreased diastol ic blood pressure 15 min after ingestion, while 1 h after ingestion di astolic blood pressure was the same with tyrosine and placebo. No effe cts on mood, systolic blood pressure and heart rate were found.