[Current problems of animal amino acid and vitamin nutrition]. / Aktual'nye problemy aminokislotnogo i vitaminnogo pitaniia zivotnykh.

Biochemical functions of certain amino acids and their role in improving fodder protein are described. Different aspects of biological significance of proteins and methods of its increase are discussed. It is indicated that concentrates prepared from green plants and starch- and cellulose-containing materials proteinized under the action of microorganisms can be used as an additional source of fodder protein. It is demonstrated that lysine and tryptophane concentrates can be effectively applied to raise the nutrient properties of fodder protein. The data are presented concerning the relations between protein and vitamin nutrition, as well as vitamin absorption and transport depending on the acceptor and receptor proteins of blood and tissues.

[Membrane digestion and absorption in the bird]. / Membrannoe pishchevarenie i vsasyvanie u ptits.

Characteristics of membrane digestion in birds as well as its role in splitting up carbohydrates and proteins revealed the regulatory character of membrane digestion enzymes, their linkage to the enterocyte membrane, dependence on the age and the topography of the small intestine. The systems of active and exchange transport as well as its energetics are described. A close connection between membrane hydrolysis and absorption is shown as actualized by specialized digestive-transport complexes functioning in the enterocyte membrane. Fast and slow adaptation of membrane digestion and absorption are described as well as the ability of parasubstrate regulation of these systems.

[Morphofunctional analysis of zinc-accumulating capacity of digestive system organs]. / Morfofunktsional'nyi analiz tsinkdeponiruiushchei sposobnosti organovpishchevaritel'noi sistemy.

The distribution of zinc and related changes have been studied in zinc--loaded chick pancreas, ileum and liver at the ultrastructural level by sulphide--silver method. White Leghorn chicks fed a high zinc diets (50, 500, 1000, 2000 and 4000 mgZn/kg diet) for 6 weeks, were killed at intervals; portions of their organs were fixed for light and electron microscopy; other samples were analyzed for zinc by AA spectrophotometry. A drastic increase of zinc level in chick pancreas fed 2000 mg Zn/kg diet (as ZnCl2) was associated with acinar cell degeneration. Apoptosis was the predominant form of acinar cell deletion. This study provides support for a previously proposed theory that cell injury stimulates passive zinc accumulation.

[Relations between the supply of vitamin D and accumulation of Pb in chickens]. / Otlozhenie Pb v organizme tsypliat v zavisimosti ot obespechennosti vitaminom D.

Lead accumulation in the body of 25-day-old chickens was studied depending on the dose of lead and the presence of vitamin D in the diet. It was found that with the increase of the dose of lead (40, 100 and 200 mg/kg feed), its level in the blood, bones, kidneys and liver grows. Introduction of vitamin D in the diet (500 IU per kg) considerably raises the content of lead in the blood (from 212 to 284 micrograms/100 ml) in bone tissues (from 29.4 to 242.7 mg per g dry substance). Single injection of vitamin D to rachitic chickens also promotes lead accumulation in the tissues. Thus a conclusion may be drawn that vitamin D stimulates lead accumulation.

[Absorption and localization of zinc in the ileum of chicks dependent on provision with vitamin A]. / Vsasyvanie i lokalizatsiia tsinka v podvszdoshnoi kishke tsypliat v zavisimosti ot obespechennosti ikh vitaminom A.

Vitamin A increase the accumulation and transport of zinc in the chick ileal mucosa. Regulating effect of this vitamin on the mentioned processes was already observed in the initial stage zinc uptake in the intestinal mucosa--its storage in the mucus layer. Stimulation of zinc absorption by vitamin A can be related to a specific carrier-vitamin A-dependent zinc-binding protein. Presence of zinc in the smooth endoplasmic reticulum of the enterocyte apical zone suggests the role of this organelle in the cation homeostasis in the cell.

[Direct stimulatory action of blood serum, vitamin D3, and its hydroxy-analogs on calcium transport in the small intestine of chicks in vitro]. / Priamoe stimuliruiushchee deistvie syvorotki krovi, vitamina D3 i ego oksi-analogov an transport kal'tsiia v tonkoi kishke tsypliat in vitro.

A study was made of the effect of blood serum, vitamin D3 and its hydroxy-analogs (25-hydroxyvitamin D4. 1 alpha-hydroxyvitamin D3) on Ca2+ transport across the wall of the noninverted small sac of D-avitaminosis chicken during incubation in vitro. It was shown that blood serum from chickens fed vitamin D3 in different doses (50--20 000 IU) and at varying time (1--72 h) before sacrifice produced a marked stimulating action on the cation transport 10 min after administration into the intestinal cavity as compared with the effect produced by the serum from D-avitaminosis chickens. Administration into the intestine of vitamin D3 or its hydroxy-analogs in physiological doses (6.25--25.0 ng) also significantly stimulated Ca+ transport over 10 min of incubation.