Abstract
1
Heptaminol stopped or delayed the progressive decline in tension which characterizes the phenomenon of fatigue in frog isolated twitch muscle fibre.
2
Heptaminol had no action on the sodium, potassium and calcium voltage‐dependent ionic conductances.
3
The hypothesis of an action via an internal alkalinization was tested by comparison with the action of NH4Cl. Both substances increased the tension.
4
The action of heptaminol was suppressed in sodium‐free (TRIS) solution or in the presence of amiloride while the action of NH4Cl was always observed.
5
These results could be explained by a stimulation of the Na/H antiport by heptaminol.