[Study in the anuran amphibian Xenopus laevis, some blood characteristics and nitrogen excretion based on changes in the water osmolarity].
The pH, the osmolality and the urea and ammonia concentrations in blood, as well as the net urea and ammonia excretions, were studied in the amphibian Xenopus laevis exposed for several weeks to increased osmotic pressure (OP) of the ambient water, as a result of the addition of either NaCl or mannitol to the water. The pH and the ammonia concentration of the blood were independent of the variations of the ambient osmolarity. On the contrary, the blood osmolality and its urea concentration increased markedly when the ambient OP was augmented. The increase of ambient OP by NaCl addition to the medium augmented the urea net excretion and slightly decreased the ammonia excretion. When the increase of ambient OP resulted from the addition of mannitol in the water, excretions of urea and ammonia became negligible.
Dejours
P
P
C.N.R.S., Centre d'Ecologie et Physiologie énergétiques, Strasbourg.
Armand
J
J
Beekenkamp
H
H
D000641:Ammonia / Q000097:blood*; D000818:Animals; D001806:Blood Urea Nitrogen; D006863:Hydrogen-Ion Concentration; D008353:Mannitol / Q000494:pharmacology; D009994:Osmolar Concentration; D009997:Osmotic Pressure / Q000187:drug effects; D012965:Sodium Chloride / Q000494:pharmacology; D014867:Water; D014982:Xenopus laevis / Q000097:blood*
D014867:Water; D008353:Mannitol; D012965:Sodium Chloride; D000641:Ammonia
Etude chez l'amphibien anoure, Xenopus laevis, de quelques caractères du sang et de l'excrétion azotée en fonction du changement de l'osmolarité de l'eau ambiante.