Die Beeinflussung der bioelektrischen und mechanischen Aktivität des Säugetiermyokards bei stufenweisem Ersatz von extracellulärem Na+durch Li+
✍ Scribed by H. -J. Freund
- Publisher
- Springer
- Year
- 1967
- Tongue
- English
- Weight
- 312 KB
- Volume
- 296
- Category
- Article
- ISSN
- 0031-6768
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✦ Synopsis
The influence of stepwise substitution of extracellular Na+ by Li + (a constant calcium concentration of 1.8 retool/1 being maintained) on contractile force, resting and action potentials of electrically stimulated isolated papillary muscles of guinea pigs was studied. Reduction of Na + below 75°/0 of normal value markedly accentuated contractile force, but decreased resting potential, overshoot and action potential duration. The results indicate that the antagonism between Na + and Ca ++ as described by L~TTGAU and NIV.D~GV, ~XE (1958) for the frog heart is also present in the mammalian myocardium. The contractile force of the latter is influenced by substitution of Na + by Li + in the same manner as by simple sodium depletion or addition of extra-calcinm.