The effects of lithium on muscle contractile function in humans

✍ Scribed by Mark A. Tarnopolsky; Audrey Hicks; Karen Winegard

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 741 KB
• Volume: 19
• Category: Article
• ISSN: 0148-639X
• DOI: 10.1002/(sici)1097-4598(199603)19:3<311::aid-mus5>3.0.co;2-g

✦ Synopsis

A side effect of lithium (Li+) treatment is fatigue. Lit decreases inositol triphosphate (IP,) accumulation and IP3 may play a role in excitationcontraction (E-C) coupling in skeletal muscle. Lit carbonate (600 mg b.i.d. x 6 days) was administered in a randomized, double-blind fashion to 12 males to measure the effect upon muscle contractile function: peak twitch torque (PTT), time to PTT, half-relaxation time, maximal voluntary contraction strength (MVC), percent motor unit activation, M-wave characteristics, and tetanic torque (3 min at 15 and 50 Hz). Lit resulted in a significant decrease in 15-and 50-Hz tetanic torque (P < 0.001), MVC, and resting PTT ( P < 0.05).

There were no effects of Li' upon any of the other measured variables. Lit had a negative effect upon E-C coupling and did not affect central motor unit recruitment. Elucidation of the role of IP3 in E-C coupling may help to understand fatigue in some neuromuscular disorders.