The experiments were carried out to elucidate the relationships between neurogenic effects of electrical transmural nerve stimulation and effect of adenosine 5´-triphosphate(ATP) to purinoceptor on the urinary bladder smooth muscle of pig. The results were as follows :
1. The contractile responses induced by electrical transmural nerve stimulation(l0V or 20V, 0.5msec, l0sec) were the frequency(2∼64Hz) dependent manner.
2. The contractile response induced by carbachol was responsed with a dose-dependent manner and the maximum contractility was 10^(-4)M.
3. The contractile responses induced by ATP were increased in a dose-dependent manner (10^(-5)∼10^(-3)M).
4. The contractile response induced by electrical transmural nerve stimulation(l0V, 2∼32㎐, 0.5msec, l0sec) was partially blocked by the treatment with atropine(10^(-5)M), and was powerfully inhibited by 3 times of addition with ATP(l0^(-5)M).
5. The contractile response induced by electrical transmural nerve stimulation(l0V, 2∼32㎐, 0.5msec, l0sec) was partially blocked by the treatment with atropine(10^(-5)M), and was completely blocked by the desensitization of the P_(2X)-purinoceptor using α, β-methylene ATP(5×10^(-5)M).
These results suggest that purinergic nerve was innervated, and ATP and acetylcholine was released by the electrical transmural nerve stimulation in urinary bladder smooth muscle of pig.
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