OSMOMETRIC AND VOLUMETRIC PROPERTIES OF THE PERITONEAL SURFACE, PRESUMABLE FROM THE CHANGE IN ACTIVITY OF THE LYMPH HEART IN THE TOAD
1968 年 15 巻 4 号 p. 179-192
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1968 年 15 巻 4 号 p. 179-192
As one of the serial experiments on the osmotic constancy within the body, the effects of intraabdominal injection of the solutions which were prepared by combining different amounts and osmolarities on the contractile property of the lymph heart were investigated in the anaesthetized toad. The properties of the peritoneal surface, respectively sensitive to the change in the volume and osmolarity in the abdominal cavity, were examined with respect to the change in amplitude and in frequency of the mechanical properties of the lymph heart.1. The lymph heart activity is controlled essentially by the spinal cord, and hence the changes occurred were reflexive in nature, except for few cases of which change in lymph heart motility was supposed to be caused by a direct effect of the solution injected on the lymph heart muscle itself.2. Heterotonic solutions which were injected into the abdominal cavity caused the change in frequency of the rhythmical lymph heart activity. Hypertonic solutions affected more strongly than hypotonic solutions. The increase in the volume of the solutions injected resulted in the addition of the increase in amplitude. The amount exceeding about 3 ml was enough to generate the volumetric response. The change in frequency was equivalent to the osmoceptive response and the change in amplitude the volumoceptive response.Isotonic solutions, either electrolytic or nonelectrolytic, when the amount was excessive, caused only volumetric response.3. Volumoceptive response was occurred immediately after the procedure, while osmoceptive response was relatively delayed even under the condition capable of producing both responses. The change in osmotic pressure of the solutions injected resulted always in the change in frequency of the motility even if the solution was hypertonic or hypotonic. The functional distinction of the osmoceptive and volumoceptive properties on the peritoneal surface was evident.
