Effect of crotamine on contraction force of isolated diaphragm of mice.

<p>The contraction of isolated mouse diaphragms was induced by transmural electrical stimulation (0.1 Hz, 2 ms duration, under optimum voltage and supramaximal voltage) and the isometric contractions were determined by plotting the average value of contraction force of each 5 min. Crotamine (from 3 to 30 nM) increased by about 17 to 46% the amplitude of twitch-contraction of isolated muscle induced by the direct transmural electrical stimuli. The time of crotamine addition was considered as zero (vertical dashed line), and the baseline contraction amplitude was considered as 100% (horizontal dashed line). The results (in percentage) were expressed as mean ± SEM (N = 6 independent experiments). The value <i>p</i> < 0.05 for ANOVA statistical analysis compared to the control was considered significant as indicated by *, ^# and ^<i>a</i>, for 30, 10 and 3 nM of crotamine, respectively.