Portal de Periódicos da CAPES

Na+ transport and impedance properties of the isolated frog gastric mucosa at different O2 tensions

1971; Elsevier BV; Volume: 225; Issue: 1 Linguagem: Inglês

10.1016/0005-2736(71)90281-1

1879-2642

Gunnar Flemström,

Diet and metabolism studies

Na+ was actively transported from the mucosal (secretory) to the serosal (nutritient) side of the isolated frog gastric mucosa at an O2 tension of 300 mm Hg in the bathing solutions. At a high (700 mm Hg) and two lower (150 and 40 mm Hg) O2 tensions no active transport of Na+ was observed. Although no elution of l-lactate into the bathing solutions was detected, the appearance of two impedance loci at O2 tensions of 300 mm Hg or lower was interpreted as evidence that the frog gastric mucosa was in a somewhat hypoxic condition when actively transporting Na+. This experimental finding may be of importance with regard to the evaluation of active transport of Na+ in the isolated mammalian gastric mucosa, which was earlier found to have a considerable production of l-lactate, indicating tissue hypoxia. Active transport of Na+ in the hypoxic gastric mucosa is suggested to be due to an asymmetric distribution of the Na2+ pump, common to most cell membranes, in the acid-secreting cells.