It was generally suggested that the intestinal motility was influenced by pH of intestinal contents.
According to "A Manual of Pharmacology" edited by Sollmann in 1944, Excised intestines of rabbits or cats, suspended in Ringer´s solution are depressed progressively by increase of acidity.
They are arrested about pH 6.2 to 6.0.
And increase of alkalinity stimulates the intestine progressively up to pH 8.0.
In this paper, the authors also observed certain influence of pH changes in Locke-Ringer´s solution on the excised intestine of rabbit. And in order to investigate the mechanism of action on the rabbit´s intestine by pH changes; we determined the electrolyte (Na, K, Mg and Ca) and cholinesterase activity in the normal intestinal tissues and diamox (carbonic anhydrase inhibitor) incubated intestine. In addition, intestinal response by diamox was studied.
The following results were obtained.
1. Excised intestines of rabbits, suspended in Locke-Ringer´s solution were depressed their tonus by increase of acidity. At pH 6.8, they showed the most profound relaxation with a little depressed motility, and complete paralysis at lower than pH 6.3.. On the contrary, increase of alkalinity stimulated the intestine progressively up to pH 9.6. On the more than pH 9.6, they showed tetanic contraction.
2. The intestinal response by the change of pH was inhibited in diamox incubated intestine.
3. The intestinal motility was not changed by diamox lower than 5 x 10-$ concentration, but increased its tonus in 10-4 .
4. Sodium and potassium contents in diamox incubated intestine were significantly decreased,
in comparison with normal intestine, but no significant change on Mg and Ca contents.
5. The electrolyte contents and cholinesterase activity in normal and diamox incubated intestine
were not influenced by pH changes in Locke-Ringer´s solution.
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