scholarly journals Salt-induced changes in sodium transport across the skin of the euryhaline toad, Bufo viridis.

1975 ◽  
Vol 247 (3) ◽  
pp. 537-550 ◽  
Author(s):  
U Katz
Keyword(s):  
Sodium Transport ◽  
Bufo Viridis ◽  
Induced Changes ◽  
Toad Bufo

NaCl adaptation in Rana ridibunda and a comparison with the euryhaline toad Bufo viridis

1975 ◽  
Vol 63 (3) ◽  
pp. 763-773
Author(s):  
U. Katz
Keyword(s):  
Water Uptake ◽  
Sodium Transport ◽  
Tap Water ◽  
Physiological Adaptation ◽  
Salt Adaptation ◽  
Osmotic Gradient ◽  
Rana Ridibunda ◽  
Bufo Viridis ◽  
Water Frogs ◽  
Toad Bufo

The physiological adaptation of the frog Rana ridibunda to saline environment was studied. It was found that blood was always hypertonic to the external solution, but at the highest salinity tolerated (i.e. 300 mOsM) the osmotic gradient across the skin was nearly abolished. Water uptake by the living frog remained unchanged, whereas sodium transport across the skin decreased markedly. Neurohypophyseal hormone increased water uptake and sodium transport to levels similar to those in tap water frogs. Water content of the tissues was not affected by saline adaptation, although it varied appreciably under acute conditions. Oxygen consumption increased in dehydrated frogs, but not in adapted ones. The results are discussed and compared to the euryhaline toad Bufo viridis; the importance of high urea levels for high salt adaptation is stressed.

On a New Species of the Genus Cosmocerca Diesing, 1861 from a Toad, Bufo viridis, in Kashmir

1959 ◽  
Vol 33 (2-3) ◽  
pp. 161-170 ◽  
Author(s):  
D. N. Fotedar
Keyword(s):  
New Species ◽  
Bufo Viridis ◽  
Male Tail ◽  
Toad Bufo ◽  
A New Species

1. A new species, Cosmocerca kashmirensis n.sp. from the toad, Bufo viridis, in Kashmir, is described. The new species has 19 plectanes in the male tail, of which 3 plectanes are simple rosettes and resemble the compound caudal papillae of the genus Cosmocercoides.2. The existing species of the genus Cosmocerca Diesing, 1861 are listed and briefly described.

Active urea transport by the skin of Bufo viridis: amiloride- and phloretin-sensitive transport sites

1988 ◽  
Vol 255 (3) ◽  
pp. F429-F433 ◽  
Author(s):  
J. Rapoport ◽  
A. Abuful ◽  
C. Chaimovitz ◽  
Z. Noeh ◽  
R. M. Hays
Keyword(s):  
External Medium ◽  
Ringer Solution ◽  
Bufo Marinus ◽  
Urea Transport ◽  
Maximal Inhibition ◽  
Experimental Conditions ◽  
Bufo Viridis ◽  
Green Toad ◽  
Dose Response Study ◽  
Toad Bufo

Urea is actively transported inwardly (Ji) across the skin of the green toad Bufo viridis. Ji is markedly enhanced in toads adapted to hypertonic saline. We studied urea transport across the skin of Bufo viridis under a variety of experimental conditions, including treatment with amiloride and phloretin, agents that inhibit urea permeability in the bladder of Bufo marinus. Amiloride (10(-4) M) significantly inhibited Ji in both adapted and unadapted animals and was unaffected by removal of sodium from the external medium. Phloretin (10(-4) M) significantly inhibited Ji in adapted animals by 23–46%; there was also a reduction in Ji in unadapted toads at 10(-4) and 5 x 10(-4) M phloretin. A dose-response study revealed that the concentration of phloretin causing half-maximal inhibition (K1/2) was 5 x 10(-4) M for adapted animals. Ji was unaffected by the substitution of sucrose for Ringer solution or by ouabain. We conclude 1) the process of adaptation appears to involve an increase in the number of amiloride- and phloretin-inhibitable urea transport sites in the skin, with a possible increase in the affinity of the sites for phloretin; 2) the adapted skin resembles the Bufo marinus urinary bladder with respect to amiloride and phloretin-inhibitable sites; 3) we confirm earlier observations that Ji is independent of sodium transport.

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