Study of potassium deficiency in cardiac muscle: quantitative X-ray microanalysis and cryotechniques.

An imbalance of potassium in cardiac muscle causes an alteration of heart function. The distribution and concentration of potassium in rat papillary heart muscle was studied using cryofixation and X-ray microanalysis. Freeze-dried cryosections and sections of freeze-dried, embedded tissue were analysed.

[Platinum localization and kidney ultrastructure in the frog after cisplatin administration].

X-ray microanalysis was used to study the localization of platinum, sodium and potassium in the frog nephrons 3 days after cisplatin administration (50 mg per kg of body weight). In the frog, like in mammals, platinum is accumulated in the proximal tubules. As evidenced by electron microscopy, the platinum content is correlated with the degree of deterioration of cell ultrastructure.

[Action of cadmium on the elemental composition and cellular morphology of the hepatopancreas, kidneys and gonads of the mussel Mytilus edulis and scallop Mizuhopecten yessoensis].

Studies have been made on the content and distribution of Cd, K, Mg, Ca, S and P in organs and cells of mussels and scallops before and after immersion in water containing cadmium chloride. In normal molluscs, the lowest content of Cd was found in the gonads; cadmium content of the hepatopancreas and kidney in the scallop is correspondingly 20 and 40 times higher than in the mussel. After immersion in water with cadmium (250 micrograms/l in summer experiments and 500 micrograms/l in spring ones), cadmium content of the hepatopancreas and kidney of the scallop was found to be also higher than that in the mussel, although the difference is less significant, being dependent on the season of year.

[Cadmium distribution in tissues and Na,K-ATPase activity of the skin of the frog Rana temporaria in different routes of cadmium uptake by the body].

Accumulation, distribution of Cd in tissues and its toxic effect depend of the mode of uptake of Cd by the organism. Subcutaneous injections of Cd (0.12-0.

Ion compartmentalization in frog oocytes as demonstrated by X-ray microanalysis.

The distributions of K, Na, Mg and Ca within frog ovarian and oviductal oocytes were studied by electron probe wavelength dispersive X-ray microanalysis. An important heterogeneity could be found both in nuclear and jelly coated oocytes. The highest K, Mg and, to a lesser extent, Na concentrations were found in the pigmented area of the peripheral cytoplasm.

[Sodium and potassium content of intrafusal muscle fibers and their resting membrane potential in different ionic media].

X-ray microanalysis revealed a high sodium concentration in intrafusal fibers of the frog-muscle whereas it appeared to be normal in extrafusal ones. Potassium concentration was practically the same both in intra- and extrafusal fibers which is in good agreement with the data obtained earlier with other techniques. Electrophysiological experiments demonstrated a similar behaviour of the resting MP found in both kinds of fibers in solutions with different ionic composition.

[Changes in the muscle ultrastructure and electrolyte composition of rats in embryogenesis. II. X-ray spectrum microanalysis of the intracellular concentrations of potassium, sodium and phosphorus in skeletal and heart muscle].

Concentrations of K, P and Na were determined in skeletal and cardiac muscle cells of rat embryos. High K and P levels--133 and 166 mmole/kg wet weight, resp.,--were found in skeletal muscles of 13 day old embryos, the concentration of Na in these cells being 81 mmole/kg w.

[Changes in the ultrastructure and electrolyte composition of the muscles of rats during embryogenesis. I. Electron microscopic study of the structure of skeletal and heart muscle].

The ultrastructure of rat skeletal and cardiac muscles during embryogenesis was studied. Uninucleated skeletal muscle myoblasts of 13 day old embryos contain no myofibrils or discrete sarcomers, although intermediate filaments (8-13 nm) are observed. In cardiomyocytes of this stage, a formation of myofibrils from thick (15-16 nm) and thin (5-7 nm) filaments takes place.

Correlation between potassium and phosphorus content and their nonuniform distribution in Acanthamoeba castellanii.

Biologically important elements: K, Na, Mg, Ca, Cl, P, and S were analyzed in Acanthamoeba castellanii. A higher potassium content, as compared with other cations, was detected. Total content of the cation-forming elements: K, Na, Mg, and Ca was ca.

[Sodium, potassium, magnesium and calcium distribution in the oocytes of the common frog based on x-ray microanalysis data].

Using X-ray microanalysis, the contents and distribution of Na, K, Mg, Ca and some other elements were studied in ovary and ovariole oocytes of the grass frog R. temporaria. The increased K and Mg concentrations were found in the oocyte cytoplasm pigmented zone.

Heterogenous distribution of potassium and phosphorus in Acanthamoeba castellanii.

Using x-ray microanalysis technique the distribution of potassium, phosphorus and sulphur was analysed in Acanthamoeba castellanii cells. Distribution of potassium was nonuniform; the high level of the element was observed in the cortex region of these cells. Distribution of phosphorus was shown to be similar to that of potassium, whereas sulphur was rather uniformly distributed.

Calcium content and distribution in egg vesicles of Galleria mellonella (Lepidoptera) as determined by X-ray microanalysis.

In egg vesicles of Galleria mellonella (Lepidoptera) electron microprobe analysis reveals calcium in concentrations of 9 and 3 mmoles per 1,000 g tissue wet weight in oocyters and accompanying trophic cells, respectively. This high average level of calcium characterizes both pre- and postvitellogenic oocytes, but the distribution of calcium is not uniform. In postvitellogenic vesicles the central area of the ooplasm shows a higher content of Ca than peripheral one, what may be correlated with the distribution of mature yolk platelets within the ooplasm.

[X-ray microanalysis of the fundamental composition of the hemolymph of the mollusk Mytilus edulis].

X-ray microanalysis of the content of Na, K, Cl, Ca, P, S and Mg has been made in ultrasmall samples of haemolymph of the mussel Mytilus edulis living in habitats with lowered salinity. It was shown that the content of potassium in the haemolymph is higher than in the environment, both natural and artificial. Coefficient of potassium accumulation in relation to the environment increases with the decrease of external salinity.

[The ionic selectivity of the membrane mechanisms for potassium transport in the neurons of Planorbarius corneus mollusks].

The in- and outflow of 204Tl, 86Rb and 137Cs in a snail brain was studied. The inward rate constants determined in the presence and without ouabain decreased as follows: Tl+ greater than Rb+ greater than Cs+. The inflow rate constants differed about 2-3 fold.

[Quantitative determination of potassium content of spinal motor neurons frogs by x-ray microanalysis].

X-ray microanalysis has been made of the potassium content of motoneurons in the frogs Rana ridibunda and R. temporaria. The tissue was frozen in isopentane up to-160 degrees, dried in vacuum at-50 degrees, embedded into epoxy resin and sectioned by ultramicrotome.