Electrophysiology of the frog gastric mucosa with sufficient CO2.
Changing from 5% CO2 in the serosal solution only to 10% CO2 on both sides doubles the acid secretory rate of the bullfrog stomach (as shown previously) and raises the transmural potential difference, although the short-circuit current is not changed. The secretory overshoot on reoxygenation after anaerobiosis, observed in 5% CO2, is virtually eliminated in 10% CO2, as predicted by the diffusion model which explains the secretory rate increase. It was found that the rate of rise of the secretory rate during anoxia was identical in the 2 conditions, which explains the increased secretory lag in 10% CO2 and suggests an interesting limitation on the rate with which acid secretion can be activated. During anoxia in 10% CO2, but not in 5% CO2, there occurs a sudden drop in PD to a slightly negative value associated with a fall in tissue resistance. This effect occurs under SCN-inhibition and thus seems unrelated to H+ transport per se. A working model is presented which can explain some of the events surrounding the sudden potential drop.
D000818:Animals; D002245:Carbon Dioxide; D004594:Electrophysiology; D005750:Gastric Juice / Q000378:metabolism; D005753:Gastric Mucosa / Q000378:metabolism / Q000502:physiology*; D006863:Hydrogen-Ion Concentration; D000860:Hypoxia; D066298:In Vitro Techniques; D008954:Models, Biological; D011892:Rana catesbeiana; D012636:Secretory Rate; D013997:Time Factors
D002245:Carbon Dioxide