1. Key words: muscular dystrophy, mdx, myogenesis, sarcolemma, ouabain-sensitive ATPase, phospholipid.

2. Propranolol and ouabain did not produce significant effects on post-stimulatory hyperemia.

3. In these tissues ouabain decreased Na efflux from the faster, larger cellular fraction (BK2 ↓) without affecting adenine nucleotide levels.

4. In muscle preparations pretreated with ouabain (3 × 10−6 M), the K+-induced undershoot was abolished and replaced by a transient contraction.

5. This compound has an IC50 of 1 μM in a [3H]ouabain binding assay, and is about 10 times more potent than the aglycone.

6. If the ion pumps are turned off by removing their energy source, or by adding an inhibitor such as ouabain, the axon can still fire hundreds of thousands of action potentials before their amplitudes begin to decay significantly.