“Supra-threshold doses of amide result in … and inotropy within 5–15 s. 5-Hydroxytryptamine … M produces diastolic arrest within 10 s. A 1-min exposure to FMRFamide (5 · 10-8M) results in … in the cytoplasmic levels of adenosine 3′,5′-cyclic monophosphate; shorter or longer exposures have no effect.”