Abstract
In dogs, cats and rabbits decerebrated under anesthesia or nonanesthesia, the intrinsic reflexes were studied in the denervated small intestine. The results are summarized as follows:
In dogs, cats and rabbits decerebrated under anesthesia or nonanesthesia, the intrinsic reflexes were studied in the denervated small intestine. The results are summarized as follows:
(a) When the surface of the mucosa was mechanically rubbed with brush or cotton-wool, or stimulated chemically with 0.1 normal solution of HCl, halfsaturated copper sulphate solution, mustard paste or crystals of sodium chloride, the excitatory state was elicited on the oral side of the stimulated region, giving rise to an increase in the strength of normal rhythmic contractions, while the inhibitory state on the anal side, eliciting a decrease in the strength of rhythmic contraction waves. This excitatory state might be occasionally so exceedingly enhanced that the ascending waves are elicited from the stimulated region. The reflex responses were elicited after the degenerative section of the mesenteric nerves concerned, while they were abolished after administration of hexamethonium.
(b) When the muscular coats were mechanically stretched or chemically stimulated, i.e., with acetylcholine, histamine, pilocarpine or BaCl2 the rhythmic contraction waves were inhibited on both sides of the stimulated region. The administration of hexamethonium as well as the degenerative section of the mesenteric nerves concerned had no influence upon the reflex responses.
(2) The discrepancies among the results obtained by previous authors would be chiefly due to the mode of stimulation, having the tendency of both the mucosal and muscular reflexes being invoked at the same time. Furthermore it was observed that the reflexes described above might play an important role to realize the polarity observed on the motility of the small intestine.
