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Action of tetrodotoxin on spontaneous electrical activity of some smooth muscle preparations

1974; Elsevier BV; Volume: 29; Issue: 2 Linguagem: Inglês

10.1016/0014-2999(74)90021-1

1879-0712

Marcello Tonini, Sergio Lecchini, Gianmario Frigo, Antonio Crema,

Ion channel regulation and function

The action of tetrodotoxin (TTX) has been studied in different smooth muscle preparations by recording mechanical and extracellular electrical activities. TTX, although able to abolish nerve-mediated reflex excitation in the small intestine, induced spontaneous firing and segmental contractions in the circular muscle. In both the intestine and the renal pelvis, the effect of TTX was maintained after cholinoceptor and adrenoceptor blockade. The results could be interpreted as evidence that a neurogenic tonic inhibition, possibly not involving cholinergic or adrenergic mechanisms, is operative in the iileum, colon and renal pelvis, and seems to be mainly directed towards the circular musculature of the small intestine.