Evaluation of the stimulatory capacity of procaine on Na transport through frog skin

• Published in: Archives internationales de physiologie, de biochimie et de biophysique Vol. 99; no. 4; p. 335
• Main Authors: Flonta, M L, Nistor, M, Frangopol, P T
• Format: Journal Article
• Language: English
• Published: Belgium 1991
• Subjects: Animals; Biological Transport - drug effects; Electric Conductivity; Guanidines - pharmacology; Procaine - pharmacology; Rana ridibunda; Seasons; Skin - drug effects; Skin - metabolism; Sodium - metabolism; Sodium Channels - drug effects; Sodium Channels - physiology; Temperature
• ISSN: 0778-3124
• DOI: 10.3109/13813459109146946

Procaine has different effects on various ionic conductive pathways through the frog skin. We investigated the season and temperature dependence of the stimulation by mucosal procaine, of the Na-conductive pathway. For this stimulation, we found higher half-maximal saturation constants (KNa) in winter animals (6.38 +/- 0.8 mmol/l), than in summer ones (4.03 +/- 0.7 mmol/l). Summer frogs kept for 2 weeks at 4 degrees C, reacted like winter frogs (6.24 +/- 0.8 mmol/l). However, the maximal sodium currents (INa max) did not depend on temperature adaptation. Procaine-induced increased of KNa is associated with an increase of INa. The effects of procaine associated with BIG (benzoylimidazole-2-guanidine) were non-additive, while with vasopressin they were additive. A biphasic, dose-dependent response was recorded after procaine application to the inner surface. Vasopressin counteracted the serosal procaine-induced inhibition of the Na-transport.