Abstract
1. In freshly prepared auricles in which tonus waves are present changing the pH of the bath from 7.4 to 7.0 causes the tonus waves to disappear (confirmation of Andrus).
2. In auricles which have been excised and kept at room temperature 20.5°C to 27°C., eighteen to forty-two hours and which still show tonus waves, changes in pH from 7.4 to 7.0 do not influence these waves. The pH of the bath has to be decreased to 6.6 to 6.2 before the tonus waves are lost.
3. Phosphate buffered Ringer's solutions are not as satisfactory as bicarbonate-HCl buffered Ringer's solutions. This is due to the fact that the phosphate ion increases the tonus waves and in many cases this change in tonus is superimposed upon the decreased tonus due to increased acidity.
4. Adrenalin cannot establish tonus waves if they are not present in the auricles.
5. If tonus waves exist adrenalin alkaloid in small doses, stimulates the positive tono-trophic sympathetic nerve fibers.
6. Adrenalin alkaloid in concentrated solutions stimulates the negative tono-trophic sympathetic nerve fibers. This decrease in tonus and tonus waves is not due to decreased pH of the bath.
7. Tyramine acid phosphate has the same actions as has adrenalin upon the tonus and tonus waves in the terrapin auricles.
8. Pure pituitary extract establishes tonus and tonus waves when they are not present and when they are present it increases them.
9. Commercial pituitary extracts, not containing preservatives have an action after neutralization similar to that of pure pituitary powder.
10. Chloretone (trichlor-tertiary butylalcohol) in such quantities as are used as a preservative in commercial pituitary preparations when added to the bath produces a loss of tonus.
11. Histamine, like pituitary extract, increases both the general tonus and tonus waves even though they were not present before the addition of the drug to the bath.
12. Adrenalin (alkaloid) in large doses antagonizes the actions of both pituitary extract and histamine.
Footnotes
- Received March 11, 1927.
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