[Cationic hydrogen exchanges in the reticulo-rumen and their significance in ruminants]. / Kation-vodorodnye obmeny v rubtse-setke i ikh znachenie u zhbachnykh zhivotnykh.

Up-to-date experimental results on mechanisms and physiological significance of mineral cations absorption in the reticulo-rumen of ruminants are observed in the review. Up to 90% of sodium, 100% of potassium and calcium and about 30-60% of magnesium pass across epithelium of the reticulo-rumen of domestic ruminants by electroneitral way through cation per hydrogen exchanges. In wild ruminant (reindeer) the item for sodium is up to 100%. Intracellular hydrogen ions are available due to carbonic anhydrase I function. The exchanges have great significance for the animals. The first, their organisms get cations mainly by metabolic products using. The second, hydrogen ions excretion is necessary for reticulo-rumen epithelial cells successful proliferation. The third, hydrogen ions excretion may be considered as a excretory mechanism of metabolic acidosis compensation in the digestive tract of ruminants. These moments may be observed as physiological mechanisms of adaptation of wild ruminants to seasonal dynamic of nutrition.

[Effect of strophanthin on the absorption of sodium and short chain fatty acids from the sheep rumen]. / Vliianie strofantina na vsasyvanie natriia i korotkotsepochechnykh zhirnykh kislot iz predzheludkov ovets.

In vivo, intraruminal strophantin administration suppressed the sodium absorption by up to 50% in the sheep reticulo-rumen. Absorption of the shortchain fatty acids was not affected. The findings suggest absence of a combined transport of sodium and short-chain fatty acids' anions in basic and lateral membranes of the reticulo-rumen apithelium in sheep.

[The role of the forestomachs in the adaptation of the alimentary function in ruminants]. / Rol' predzheludkov v adaptatsii alimentarnoi funktsii u zhvachnykh zivotnykh.

Dietary character of ruminants in the north is principally different between "nonselective" (cattle, sheep) and "selective" (reindeer, moose) species. Due to the developed polyfunctioning, forestomach in ruminants, primarily rumen and reticulum, are involved in the homeostasis formation in enteral and interior mediums, nutrients deposition and recirculation. That provides efficiency in utilization of deficient in nutrients forage and body reserves of wild ruminants during the winter. The original functional organization of absorption processes and nutrients recirculation across the multilayer epithelium of forestomach also promotes realization of the two levels metabolism during the year and adaptation of wild ruminants to season dynamics of nutrition.

[Effect of acetazolamide on sodium and potassium absorption in the sheep forestomach]. / Vliianie atsetazolamida na vsasyvanie natriia i kaliia iz predzheludkov ovets.

I.v. Acetazolamide administration suppressed the sodium and potassium absorption up to 90 and 100%, resp., in the sheep reticulo-rumen. Absorption of the short chain fatty acids was not affected. The findings suggest a sodium/potassium exchange processes occurring in the reticulo-rumen epithelium in ruminants.

[Water and electrolyte metabolism in the isolated rumen of sheep after carbonic anhydrase inhibition]. / Obmen vody i élektrolitov v izolirovannykh prezheludkakh ovets pri ingibirovanii karboangidrazy.

The exchange of mineral and low-molecular organic ions through the wall of the sheep temporarily isolated forestomach in carbonic anhydrase inhibition, were studied. The physiological significance of carbonic anhydrase for absorption of some ions in the rumen is discussed.