Contralateral Effects of Sodium and Potassium on the Electrical Potential in Frog Skin and Toad Bladder

Nature ◽  
1965 ◽  
Vol 207 (4992) ◽  
pp. 45-46 ◽  
Author(s):  
FRED M. SNELL ◽  
TUSHAR K. CHOWDHURY
Keyword(s):  
Frog Skin ◽  
Electrical Potential ◽  
Toad Bladder ◽  
Sodium And Potassium ◽  
Contralateral Effects

OSMOTIC INHIBITION OF THE NATRIFERIC RESPONSE OF THE TOAD URINARY BLADDER TO VASOPRESSIN

1975 ◽  
Vol 67 (1) ◽  
pp. 119-125
Author(s):  
P. J. BENTLEY
Keyword(s):  
Urinary Bladder ◽  
Water Movement ◽  
Short Circuit ◽  
Electrical Potential ◽  
Short Circuit Current ◽  
Toad Bladder ◽  
Toad Urinary Bladder ◽  
Electrical Potential Difference ◽  
Osmotic Gradient

SUMMARY The electrical potential difference and short-circuit current (scc, reflecting active transmural sodium transport) across the toad urinary bladder in vitro was unaffected by the presence of hypo-osmotic solutions bathing the mucosal (urinary) surface, providing that the transmural flow of water was small. Vasopressin increased the scc across the toad bladder (the natriferic response), but this stimulation was considerably reduced in the presence of a hypo-osmotic solution on the mucosal side, conditions under which water transfer across the membrane was also increased. This inhibition of the natriferic response did not depend on the direction of the water movement, for if the osmotic gradient was the opposite way to that which normally occurs, the response to vasopressin was still reduced. The natriferic response to cyclic AMP was also inhibited in the presence of an osmotic gradient. Aldosterone increased the scc and Na+ transport across the toad bladder but this response was not changed when an osmotic gradient was present. The physiological implications of these observations and the possible mechanisms involved are discussed.

31P nuclear magnetic resonance analysis of frog skin

1982 ◽  
Vol 243 (1) ◽  
pp. C74-C80 ◽  
Author(s):  
L. E. Lin ◽  
M. Shporer ◽  
M. M. Civan
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Epithelial Cells ◽  
Inorganic Phosphate ◽  
Frog Skin ◽  
Short Circuit ◽  
Toad Bladder ◽  
Nuclear Magnetic Resonance Analysis ◽  
31P Nuclear Magnetic Resonance ◽  
Nuclear Magnetic

The intracellular phosphate composition of whole and split frog skins has been studied by 31P nuclear magnetic resonance (NMR) analysis. The spectra were similar to those previously recorded from isolated epithelial cells of toad bladder. However, qualitative differences were noted in comparison with spectra from whole toad bladder. The 31P spectra from whole frog skin reflect the intracellular compositions of the epithelial cells, whereas subepithelial elements contribute significantly to the total observed 31P signals from toad bladder. Analyzed at 4 degrees C, the average phosphocreatine (PCr) and ATP concentrations of frog skin are of similar magnitude. The ratio of [PCr] to [ATP + ADP] depends on time, tissue oxygen tension, temperature, and extracellular inorganic phosphate concentration. Both this ratio and the short-circuit current (measured in parallel experiments) fell during the course of aerating frog skins in Ringer solution at room temperature. The intracellular inorganic phosphate (Pi) signal was identified. After reduction of extracellular pH, the signal did not shift immediately but subsequently did undergo an acid shift.

Sign in / Sign up

Export Citation Format

Share Document