Decreased taurine concentration in skeletal muscles after exercise for various durations.
OBJECTIVE
To examine the changes of taurine concentrations in blood and skeletal muscles after transient exercise.


METHODS
Rats were placed on a treadmill set at 25 m.min-1. The animals were divided into four groups: control (no exercise) and exercise groups 1, 2, and 3. The exercise duration for groups 1, 2, and 3 was 30, 60, and 100 +/- 12.5 min (to exhaustion: mean +/- SD), respectively. We examined the plasma concentrations of taurine and lactate, the serum concentrations of sodium and chloride ions, as well as the skeletal muscle taurine content in the soleus (slow-twitch fiber dominant type), gastrocnemius (slow- and fast-twitch fiber mix type), and plantaris and extensor digitorum longus (fast-twitch fiber dominant type) muscles.


RESULTS
Although the plasma taurine concentration was not affected by the increased exercise duration, that in skeletal muscles was significantly decreased. The gastrocnemius and plantaris muscles from the exercise group 3 had a significantly lower concentration of taurine than those of the control group. The extensor digitorum longus taurine concentration from the different exercise groups was significantly decreased compared with that from the control group. However, there was no significant difference among the exercise groups.


CONCLUSIONS
Taurine concentration was decreased in all skeletal muscles after exercise, regardless of the duration. Moreover, this decrease was specific to fast-twitch dominant fibers. However, under these conditions, the plasma taurine concentration remained unchanged.
Matsuzaki
Yasushi
Y
Departments of Gastroenterology and Orthopaedics, Institute of Clinical Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan. ymatsuzaki-gi@umin.ac.jp
Miyazaki
Teruo
T
Miyakawa
Syunpei
S
Bouscarel
Bernard
B
Ikegami
Tadashi
T
Tanaka
Naomi
N
D000818:Animals; D002712:Chlorides / Q000097:blood; D019344:Lactic Acid / Q000097:blood; D018482:Muscle, Skeletal / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012964:Sodium / Q000097:blood; D013654:Taurine / Q000378:metabolism*; D013997:Time Factors
D002712:Chlorides; D013654:Taurine; D019344:Lactic Acid; D012964:Sodium