Figure 6. Lat-B (10 μm) and twitch tension.

Twitch tension from a sartorius muscle. The record shows that the inhibitory effect of Lat-B on the hypotonic response of the Na⁺ pump is not due to a non-specific disruption of muscle structural integrity, since a prolonged exposure (117 min) to this toxin does not generate any substantial change in twitch tension, which means that this toxin produces no significant electrical and/or mechanical disarray of the fibres. The two tension spikes are artefacts produced by the solution changes: application (downward arrow) and withdrawal (upward arrow) of the toxin. Frequency of stimulation: 0.1 Hz.