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Comparative study of the concentrating mechanism in the kidney of the big gerbil (Rhombomys opimus L.) and the water vole (Arvicola terrestris L.)

1980; Elsevier BV; Volume: 66; Issue: 3 Linguagem: Inglês

10.1016/0300-9629(80)90198-x

0300-9629

Л. Н. Иванова, Natochin IuV, E. P. SEREBRYAKOV, O. A. Goncharevskaya, L.G Knyazkova, Lavrova Ea, N.I Nasledova, N. I. Pechurkina, G.V Podsekaeva, Shakhmatova Ei,

Circadian rhythm and melatonin

1. Rodents of the species studied are able to produce a hypoosmotic urine at water diuresis; the urine to plasma osmotic concentration ratio under dehydration in the water vole is 3.8 ± 0.3, in the albino rat—7.0 ± 0.2, and in the big gerbil—12.7 ± 0.9. 2. Microanatomical data agree with the hypothesis of the countercurrent multiplication. 3. The sodium and urea content, under dehydration, increases in the renal papilla of the big gerbil and the water vole as well; the level of potassium, calcium and magnesium remains unchanged. The papilla to cortex gradient of sodium and urea concentrations in the desert rodent is significantly higher than in the vole. 4. Both in the big gerbil and the water vole, the highest succinate dehydrogenase activity is characteristic of tubules of the cortex and the outer medulla but it is not observed in tubular cells of the papilla; a high level of the lactate dehydrogenase activity is also found in the renal papilla structures. The increase of the ability to produce a hyperosmotic urine does not depend on a change of the cellular energetic metabolism type. 5. The adaptive evolution of the renal concentrating ability in water-loving and desert rodents was followed by the change of the Henle's loop length and by the modification of some medullar interstitial structures.