Send to

Choose Destination
Neurosci Lett. 2001 Jul 27;308(1):25-8.

Caffeine inhibits exercise-induced increase in tryptophan hydroxylase expression in dorsal and median raphe of Sprague-Dawley rats.

Author information

Kohwang Medical Research Institute, College of Medicine, Kyung Hee University, Dongdaemun-gu, Seoul, South Korea.


Effect of caffeine on the expression of tryptophan hydroxylase (TPH), rate limiting enzyme of serotonin synthesis, in dorsal and median raphe was investigated via immunohistochemistry. In exercise groups, Sprague-Dawley rats were put on treadmill running for 30 min per day for 6 consecutive days. On the seventh day, animals of control-with-caffeine group were injected subcutaneously with 4 mg/kg caffeine, while control-without-caffeine group were injected with 0.9% NaCl, sacrificed 2 h later. Exercise-with-caffeine group and exercise-without-caffeine group were injected with caffeine and NaCl, respectively; all-out time was determined 1 h after injection, and then sacrificed. Caffeine increased all-out time in exercised rats, and inhibited the exercise-induced elevation in TPH expression. The suppressive effect of caffeine on TPH expression in exercised rats can be suggested as one possible ergogenic mechanism of caffeine.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center