title: Caffeine inhibits exercise-induced increase in tryptophan hydroxylase expression in dorsal and median raphe of Sprague-Dawley rats.
abstract: 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.
authors.affiliation: Kohwang Medical Research Institute, College of Medicine, Kyung Hee University, Dongdaemun-gu, Seoul, South Korea.
authors.forename: B V
authors.initials: BV
authors.lastname: Lim
authors.forename: M H
authors.initials: MH
authors.lastname: Jang
authors.forename: M C
authors.initials: MC
authors.lastname: Shin
authors.forename: H B
authors.initials: HB
authors.lastname: Kim
authors.forename: Y J
authors.initials: YJ
authors.lastname: Kim
authors.forename: Y P
authors.initials: YP
authors.lastname: Kim
authors.forename: J H
authors.initials: JH
authors.lastname: Chung
authors.forename: H
authors.initials: H
authors.lastname: Kim
authors.forename: M S
authors.initials: MS
authors.lastname: Shin
authors.forename: S S
authors.initials: SS
authors.lastname: Kim
authors.forename: E H
authors.initials: EH
authors.lastname: Kim
authors.forename: C J
authors.initials: CJ
authors.lastname: Kim
mesh_terms: D000818:Animals; D002110:Caffeine / Q000494:pharmacology*; D000697:Central Nervous System Stimulants / Q000494:pharmacology*; D005080:Exercise Test; D007150:Immunohistochemistry; D008297:Male; D009474:Neurons / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D010805:Physical Conditioning, Animal; D005082:Physical Exertion / Q000187:drug effects* / Q000502:physiology; D011903:Raphe Nuclei / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012701:Serotonin / Q000096:biosynthesis*; D014365:Tryptophan Hydroxylase / Q000187:drug effects* / Q000378:metabolism
chemical_list: D000697:Central Nervous System Stimulants; D012701:Serotonin; D002110:Caffeine; D014365:Tryptophan Hydroxylase