Journal of Nutrition and Health
- Volume 26 Issue 7
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- Pages.858-866
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- 1993
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- 2288-3886(pISSN)
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- 2288-3959(eISSN)
Effect of High-tyrosine Diet on Brain Norepinephrine Metabolism in Immobilization-Stressed Rats
- Yoon Hae Seong (Department of Food and Nutrition, Seoul National University, Seoul Korea)
- Published : 1993.10.01
Abstract
S.D.rats were fed with 3.4% tyrosine supplemented diet for 5 days. Tyrosine diet had no effects on brain NE and MHPG-SO4 levels in non-stressed rats. When these animals were given 3 hr-immobilization stress, they responded in a manner that coped better to the stress. This was measured by the increase in brain MHPG-SO4 indicating the increase in norepinephrine turnover by the stressed animals. When rats were stressed, fed basal or high-tyrosine diet, brain tyrosine concentration dropped more than 26% over the non-stress control animals. 3-hr immobilization stress also decreased brain NE levels. However, while the stress resulted in a significant decrease(p<0.05) of brain NE in basal diet, the decrease was not significant in high-TYR diet group. And as the stress index, serum corticosterone, glucose, and free fatty acid concentratons also were assayed. In this study, it was found that high-TYR diet prevented the stress-induced depletion of brain NE and suppressed the rise in serum corticosterone, glucose, and free fatty acid. These results suggest that high-TYR diet increases the coping ability of body to stress.