Physiol. Res. 52: 123-129, 2003

Changes in the Superoxide Production and Other Macrophage Functions Could Be Related to the Mortality of Mice with Endotoxin-Induced Oxidative Stress


Department of Physiology, Gondar College of Medical Sciences, Gondar, Ethiopia, 1Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic and 2Carl-Ludwig-Institute of Physiology, University of Leipzig, Leipzig, Germany

Received September 2, 2002
Accepted November 29, 2002

The effects of lyotropic (swelling) anions (
Cl-, Br-, NO3- and I-) on contractile properties of fast-twitch extensor digitorum longus (EDL) and slow-twitch soleus (SOL) muscles were investigated in vitro at 20 °C and 35 °C. Isolated muscles bathed in anionic Tyrode solution were stimulated directly and isometric single twitches and fused tetanic contractions were recorded. In a Cl- Tyrode solution a decrease of the bathing temperature led to a cold potentiation of the twitch tension (Pt) in EDL muscles, however, to a cold depression in SOL muscles, in both muscles combined with a prolongation of contraction (CT) and half relaxation (HRT) times. The extent and order of the potentiating effect of lyotropic anions on the Pt, CT and HRT in EDL and SOL were quite similar and increased in the order: Cl-< Br- < NO3- < I-. Since the lyotropic anions did not influence tetanic tensions, the twitch-tetanus ratio (TTR) was increased in NO3- and I- solutions. All effects of the anions were rapidly and completely reversed in both muscles when the test solution was replaced by the normal one. The temperature decrease caused no significant alteration in the potentiation capacity of the anions or in the kinetics of their action and reversibility.

Key words
Slow and fast muscles • Contractile properties • Twitch potentiation • Lyotropic anions • Temperature • Rat

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© 2003 by the Institute of Physiology, Czech Academy of Sciences