Fig. 4.
Evaluation of aminopyridine derivatives on ventilation. Mice were challenged with 2.2x LD50 BoNT/A (i.v.) and monitored for respiratory signs of botulism. Once mice developed severe abdominal paradox, baseline measurements were made, and mice were treated s.c. with vehicle (n = 14), 3,4-DAP (n = 25), 2,4-DAP (n = 16), 3,4,5-TAP (n = 12), 4-AP (n = 11), deuterated 4-aminopyridine (4-AP-d4) (n = 11), 3,4-DAP-d3 (n = 8), 3F-4AP (n = 8), 2-fluoro-4-aminopyridine (2F-4AP) (n = 6), or 3,4DF-4AP (n = 3) and monitored for 90 minutes. (A) Structures of experimental aminopyridines. 3,4-DAP is included for comparison. (B) Summary of physicochemical properties. Lipophilicity (LogP) values were derived from Pubchem (https://pubchem.ncbi.nlm.nih.gov), whereas negative logarithm of the acid dissociation constant (pKa) values were derived from Chemicalbook (https://www.chemicalbook.com). All values were confirmed against published literature when available. (C–E). Ventilatory recordings were normalized to baseline values for each mouse, averaged within each treatment condition, and presented as normalized MV (C), normalized TV (D), and normalized RR (E). Baseline values were not different among treatment conditions for MV [F(10, 107) = 1.33; P = 0.22, two-way ANOVA], TV [F(10, 107) = 0.78; P = 0.65, two-way ANOVA], or RR [F(10, 107) = 0.86; P = 0.57, two-way ANOVA]. Solid lines represent time points that are significantly different than vehicle (P < 0.05; repeated measures two-way ANOVA with Dunnett’s multiple comparison test). (F) Maximum fold changes in RR and MV were determined for each mouse, averaged within each condition, and plotted as mean ± S.E.M. Details of statistical comparisons are provided in Supplemental Table 1.