Autoregulation of apical sodium entry in the colon of the frog (Rana esculenta).
1. Na transport (INa) in the K-depolarized colon of the frog was investigated by electro-physiological current-voltage analysis. 2. INa and the intracellular Na activity [(Na)c] increased with increasing mucosal Na concentration ([Na]m), whereas the apical Na-permeability (PNam) and the transepithelial resistance (RT) decreased. 3. The results are consistent with a Na self-inhibition mechanism; however, a feedback inhibition of INa by intracellular Na must also be considered.
Krattenmacher
R
R
Institut für Veterinärphysiologie, Freie Universität Berlin, FRG.
Clauss
W
W
D000818:Animals; D001692:Biological Transport; D003106:Colon / Q000378:metabolism*; D004848:Epithelium / Q000378:metabolism; D006706:Homeostasis; D066298:In Vitro Techniques; D010539:Permeability; D011893:Rana esculenta / Q000378:metabolism; D012964:Sodium / Q000378:metabolism*
D012964:Sodium