Abstract
1. By the use of segments of the isolated cat's ileum treated with various concentrations of DFP, the effects of the drug on spontaneous contractions have been correlated with the degrees of inhibition of the total, specific and non-specific ChE activities. The approximate inhibitions of the enzymes at different regions have been determined histochemically.
2. Concentrations of DFP (10-8 - 10-6M) having no or comparatively little effect on specific ChE but markedly inhibiting non-specific ChE produced increases in tonus, and occasionally in the amplitude of contractions.
3. The distributions of the two enzymes in the cat's ileum are described in detail.
4. The findings support the hypothesis that non-specific ChE promotes the hydrolysis of endogenously liberated ACh at certain sites.
Footnotes
- Received June 22, 1950.
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