title: Evaluation of the stimulatory capacity of procaine on Na transport through frog skin.
abstract: 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.
authors.affiliation: University of Bucharest, Faculty of Biology, Biophysical Laboratory, Romania.
authors.forename: M L
authors.initials: ML
authors.lastname: Flonta
authors.forename: M
authors.initials: M
authors.lastname: Nistor
authors.forename: P T
authors.initials: PT
authors.lastname: Frangopol
mesh_terms: D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D004553:Electric Conductivity; D006146:Guanidines / Q000494:pharmacology; D011343:Procaine / Q000494:pharmacology*; D011895:Rana ridibunda; D012621:Seasons; D012867:Skin / Q000187:drug effects / Q000378:metabolism*; D012964:Sodium / Q000378:metabolism*; D015222:Sodium Channels / Q000187:drug effects / Q000502:physiology; D013696:Temperature
chemical_list: D006146:Guanidines; D015222:Sodium Channels; D011343:Procaine; C032996:2-benzimidazolylguanidine; D012964:Sodium