[The characteristics of the effect of mediator substances on the dynamic oxygen tension in the gastric mucosa].

The studies on rats were carried out to determine dynamics of pO2 in the mucous membrane of the stomach under the effect of acetylcholine, norepinephrine, serotonin, histamine, prostaglandin E2 and ATP. As to the changes in pO2 the mediator substances were arranged as follows (from more intensive effect to less pronounced one): serotonin, acetylcholine, prostaglandin E2, norepinephrine, histamine and ATP. As to the duration of the action--PGE2 acetylcholine, serotonin, norepinephrine, ATP and histamine.

[The cholinomimetic activity of alkyltrimethylammonium compounds in experiments on the isolated mollusk neuron and on frog and chicken skeletal muscle].

As revealed by contractile reaction of frog and chick muscles and by changes in the membrane current of isolated molluscan neurone, cholinomimetic activity of alkyltrimethylammonium compounds (ATMC) in the highest in drugs with 4 and 5 methylene groups in a molecule. The decrease in the activity with the decrease in the number of methylene groups was more evident in chick muscle; the decrease in the activity due to the increase in the number of these groups was most significant in experiments on molluscan neurone. Analysis of membrane current fluctuations showed that elementary current does not depend, whereas channel open time only slightly depends on the number of methylene groups in ATMC.