[A micromanipulator for the microscope photometer]. / Mikromanipuliator dlia mikroskopa-fotometra.

A micromanipulator is described to be designed for micro-operations on cells and for various cytological investigations using microelectrodes especially when cell scanning with inserted microinstrument is required. The baseplate of positioners is a light plate located on the microscope stage immediately. Thus, it is possible to do the following operations: to move the object in the field of vision of the microscope simultaneously with the inserted instrument; to insert several microinstruments into one cell; to make photometry of the cell with the inserted instrument by the scanning method. The positioners bear mechanical micromanipulator which ensures the moving of the instrument in three coordinates (8 mm lengthwise, 3 mm crosswise, and 4 mm in upright position). The micromanipulator can be employed with any type of biological microscopes and makes it possible to use objectives of high magnification (up to 100x). A little weight of the instrument (1 kg) makes it convenient to be used in the expedition.

[A flow chamber for the intravital cytophotometry (microscopy) of muscle and nerve fibers and for the intracellular microelectrode lead take-off of biopotentials]. / Protochnaia kamera dlia prizhiznennoi tsitofotometrii (mikroskopii) myshechnykh i nervnykh volokon i vnutrikletochnogo mikroéletrodnogo otvedeniia biopotentsialov.

A chamber is described with permanent solution flux aimed for in vivo cytophotometry (microscopy) of the nerve and muscle fibres, and for microelectrode registration of biopotential. Little size and construction peculiarities of the chamber make it possible to use objectives of middle and high magnification and to insert a microinstrument into the fiber.

[Transport of monosaccharides in model systems: inhibition of sugar transport in frog muscle fibers, treated with glutaraldehyde]. / Transport monosakharidov v modelnykh sistemakh: ingibirovanie transporta sakharov v myshechnykh voloknakh liagushki, obrabotannykh glutaral'degidom.

The entry of D-xylose, a permeable non-metabolizing glucose analog, in the frog muscle fibers was examined. The sugar transport system activity was established in the frog muscle fibers treated by 0.3% glutaraldehyde. The basal transport as well as insulin activated D-xylose transport was seen preserved. Sugar transport inhibitors, phlorizin, phloretin and cytochalasine B reduce the rate of D-xylose transport in this "glutar model" of a muscle fiber. A long treatment by glutaraldehyde (3.5 hours at 4 degrees C, and 1 hour at 20 degrees C) leads to a 40% decline in the entry rate of D-xylose.

[The action of inhibitors of sugar transport phlorizin, phloretin and cytochalasin B in model systems]. / Issledovanie deistviia ingibitorov transporta sakharov floritsina, floretina i tsitokhalazina B v model'nykh sistemakh.

Phlorizin, phloretin and cytochalasin B are known to be specific sugar transport inhibitors. A study was made of their effects on the carbohydrate-protein interaction in solution as a model system for examining the initial steps of sugar membrane transport. Glycogen precipitation by concanavalin A is inhibited only by alpha-methylmannoside, whereas both phlorizin and phloretin inhibit interactions between hexokinase and glucose, and between glucose-6-phosphate dehydrogenase and glucose-6-phosphate. Cytochalasin B was found to exert no effect on both the concanavalin A--glycogen interaction and the enzyme reactions investigated. The data obtained in the model system examination may suggest that the sites of glucose and cytochalasin binding are, respectively, spatially uncoupled.

[Change in transport kinetics of D-xylose in frog muscle fibers due to the specific inhibitors of sugar transport phlorhizin and phloretin]. / Izmenenie kinetiki transporta D-ksilozy v myshechnye volokna liagushki pri deistvii spetsificheskikh ingibitorov transporta sakharov floritsina i floretina.

The phloretin and phlorizin inhibition kinetics of D-xylose transport into muscle fibres of Rana temporaria has been studied. Phlorizin inhibits the entry of D-xylose competitevely and reversibly with Ki = 2.8 . 10(-4)M. Ki =9.8 . 10(-5)M has been attributed for phloretin inhibition. Phloretin inhibition was slightly reversible and depended on the state of muscle fibres. The decree of inhibition of sugar exit did not exceed that of sugar entry into the muscle fibres. The effect of phlorizin (5 . 10(-5) and 1 . 10(-4)M) and phloretin (2 . 10(-4)M) was not additive.