| Abstract: | Studies have been made on the sensitivity of cholinoreceptors in identified isolated neuron from the pedal ganglion of the snail Planorbarius corneus and cholinoreceptors of m. rectus abdominis of the frog Rana temporaria to drugs which differ from acetylcholine by the structure either in cationic group, methylene chain, or ester group. Snail cholinoreceptors were found to be less sensitive to changes in the structure of cationic group and more sensitive to the increase in methylene chain from 3 to 4 groups, as compared to frog cholinoreceptors. The sensitivity of both preparations to changes in ester group, as well as to tetramethylammonium was found to be practically the same. Therefore, the sensitivity of neuronal cholinoreceptors in the snail to the effect of acetylcholine and tetramethylammonium analogues does not significantly differ from the sensitivity of cholinoreceptors in the abdominal muscle of the frog. |
