title: [Adaptive evolution of osmoregulation in rodents with different ecologies].
abstract: Studies have been made on osmoregulation in aquatic rats (Arvicola terristris), cotton rats (Sigmodou hispidus) and Wistar albino rats under the conditions of usual salt-water regimen and 3-day water deficiency. In water-loving rodents, water deficiency results in significant changes in blood constants which charasterize osmotic homeostasis (sodium and urea concentration, the osmolarity). In albino rats, the state of dehydration is accompanied by a significant increase in antidiuretic activity of the blood serum and by an increase in osmotic concentrating index up to 7.4 +/- 0.2. In A. terestris and S. hispidus, despite of the increase in antidiuretic activity of the blood serum, no significant increase in U/Posm was found (2.7 +/- 0.2 and 4.8 +/-0.3 respectively). Low effectiveness of osmotic concentration in water-loving rodents is due to structural and functional rearrangement of the concentrating mechanism of the kidney, and, as a result, to the decrease in intrarenal gradients of sodium and urea. These peculiarities determine ecological specialization of osmoregulatory system.
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D005075:Biological Evolution; D003681:Dehydration / Q000503:physiopathology; D004463:Ecology; D005260:Female; D007668:Kidney / Q000502:physiology; D008297:Male; D009994:Osmolar Concentration; D051381:Rats; D012377:Rodentia / Q000502:physiology*; D012964:Sodium / Q000032:analysis; D013997:Time Factors; D014508:Urea / Q000032:analysis; D014667:Vasopressins / Q000097:blood; D014868:Water Deprivation; D014882:Water-Electrolyte Balance
chemical_list: D014667:Vasopressins; D014508:Urea; D012964:Sodium
vernacular_title: O adaptivnoĭ évoliutsii osmoreguliatsii u gryzunov s razlichnoĭ ékologieĭ