Panels A–C show representative ACh (top) and d4 ACh (bottom) chromatograms from wildtype (A), p75 −/− (B), and gp130 KO (C) mice. (D) Total atrial ACh content was greater in gp130 KO mice (5.4±0.4 pmol/mg, n=4) than in WT (2.5±0.4 pmol/mg, n=10) and p75 −/− (2.9±0.4 pmol/mg, n=6) mice. (E) Stimulus-evoked release of ACh was also higher in the gp130 KO mice (200±30 fmol/mg) when compared to WT (100±10 fmol/mg) or p75 −/− (90±20 fmol/mg) mice. Data are mean±SEM, *p<0.05, **p<0.01.