“From these results, it is concluded that tetrodotoxin and guanidine or methylguanidine would be antagonistic at the presynaptic site of sympathetic nerve ending.”
“In the hypogastric nerve-vas deferens preparation of the guinea-pig, the contractions of the vas deferens induced by the electrical … hypogastric nerve were suppressed after the administrations of crystalline tetrodotoxin 5×10-8M and procaine 10-4M, and the suppression by tetrodotoxin … guanidine 10-3M or … temporally antagonized.”
“The antagonistic phenomena between crystalline tetrodotoxin and guanidine in the sympathetic nerve-smooth muscle preparations were investigated and the following results were obtained.”