Here is my attempt to simplify and clarify.
As suggested by the concentration-dependent displacement of specifically bound 3 H-ouabain from its receptor (sarcolemmal Na+ /K+ -ATPase), WS 1442 seems to increase the force of contraction by inhibition of the sodium pump.
What is suggested is that WS 1442 seems to increase the force of contraction by inhibition of the sodium pump.
Or said another way,
There is a concentration-dependent displacement of specifically bound 3 H-ouabain from its receptor. The receptor is sarcolemmal Na+ /K+ -ATPase. This suggests that WS 1442 seems to increase the force of contraction by inhibition of the sodium pump.
Or
When WS 1442 increases the force of contractions also increase because the WS 1442 displaces the specifically bound 3 H-ouabain from its receptor.
But, this is somewhat of a guess on my part.