Role of circulation in maintaining Na+ and K+ concentration in pelvic patch in Rana catesbeiana.
Skin samples from the pelvic, pectoral, and back areas of frogs were taken from control (C) animals and from dehydrated animals under three conditions: dehydrated and not exposed to a bathing medium (D), dehydrated live and ventral surface exposed to a bathing medium (DL), and dehydrated with heart stopped and ventral surface exposed to a bathing medium (DHS). The skin concentration of Na+ and K+ of the pelvic patch in the absence of circulation was significantly reduced [DHS 286 +/- 22 microM/mg dry wt (n = 6)] compared with control [C 392 +/- 21 microM/mg dry wt (n = 8)]. However, the pelvic skin concentration was maintained in a frog with an intact circulation [DL 381 +/- 26 microM/mg dry wt (n = 7)] even in the presence of a high pelvic water flow [684 +/- 105 cm3.cm-2.s-1.10(-7) (n = 13)]. The water uptake in the pectoral region [231 +/- 54 cm3.cm-2.s-1.10(-7) (n = 13)] was not high enough to predict a dilution, and none was found. The concentrations were 354 +/- 21 (n = 8), 359 +/- 22 (n = 7), 353 +/- 26 (n = 7), and 373 +/- 45 microM/mg dry wt (n = 6) for C, D, DL, and DHS, respectively. Examination of the Na+ and K+ concentrations separately in the pelvic skin shows that the lower salt content in DHS frogs is mainly due to a loss of Na+.(ABSTRACT TRUNCATED AT 250 WORDS)
Parsons
R H
RH
Department of Biology and Biophysics Center, Rensselaer Polytechnic Institute, Troy, New York 12180-3590.
Schwartz
R
R
D000818:Animals; D001775:Blood Circulation / Q000502:physiology*; D003681:Dehydration / Q000503:physiopathology; D006321:Heart / Q000502:physiology; D066298:In Vitro Techniques; D010388:Pelvis; D011188:Potassium / Q000378:metabolism*; D011892:Rana catesbeiana; D012867:Skin / Q000098:blood supply / Q000503:physiopathology; D012879:Skin Physiological Phenomena; D012964:Sodium / Q000378:metabolism*; D014882:Water-Electrolyte Balance
D012964:Sodium; D011188:Potassium