[Seasonal changes in the testes of the silver fox]. / Sezonnye izmeneniia semennikov serebristo-chernykh lisits.

In 14 mature male silver foxes in spring and autumn by means of counting dots and transsections, relative and absolute summational volumes and areas of the seminiferous tubule surfaces, interstitial glandulocytes (Leydig's cells) and stroma have been calculated. Average diameter and total length of the tubules have been determined. Increased mass of the testes in spring is the result of a proportional enlargement of the total volume of the seminiferous tubules and stroma, while the total volume of the endocrinic part in the organ changes insignificantly. The increase of the total volume of the seminiferous tubules occurs at the expense of the increasing diameter, though their total length remains the same.

[Relative hypertrophy of the right ventricle in silver foxes selected for domestication behavior]. / Otnositel'naia gipertrofiia prvogo zheludochka serdtsa u serebristo-chernykh lisits, selektsioniruemykh na domestikatsionnoe povedenie.

Silver foxes selected for domestication behavior were found to have relative hypertrophy of the right heart ventricle, which was 21% as enlarged in males and 18% as enlarged in females as compared with non-domesticated animals. It was established by stereological methods that hypertrophy occurs mainly at the expense of an increase in the absolute and relative content of myofibrils in cardiomyocytes, with the absolute total volume of the mitochondria being equal both in domesticated and non-domesticated animals. It was shown by means of dissociated cell counts that in both animal groups, the absolute number of cardiomyocytes and their nuclei in the right ventricles is approximately similar. It is suggested that there is a relationship between right heart ventricle hypertrophy in domesticated foxes and variation in the balance of sympathetic and parasympathetic effects.

[Adrenaline-induced damage to the myocardium in rats with genetically determined arterial hypertension]. / Adrenalinovye povrezhdeniia miokarda u krys s nasledstvenno obuslovlennoi arterial'noi gipertensiei.

Genetically hypertensive and normotensive rats were subjected to acute myocardial injury by a single subcutaneous injection of adrenaline (0.5 mg/100 g bw). The animals were sacrificed one day later. The lesions showed the signs of focal coagulative necrosis and intracellular myocytolysis. The damaged cardiomyocytes with high sarcolemmal permeability for blood plasma proteins were more widespread in the hypertensive versus normotensive rats. Intracellular myocytolysis, which is not associated with alterations in the cell membrane, was found in both experimental groups at an equal rate. The data agree with the concepts of alterations in biological membranes in genetically determined arterial hypertension.

[Ratio of spontaneous and o-aminoazotoluene-induced hepatocarcinogenesis in mice]. / Sootnoshenie spontannogo i indutsirovannogo o-aminoazotoluolom gepatokantserogeneza u myshei.

No correlation was found between the frequency of spontaneous and o-aminoazotoluene (o-AAT)-induced hepatic tumours in mice. High susceptibility to tumour induction with o-AAT in mice both genetically susceptible (strains CBA and A/He) and resistant (strains DBA/2J and DD) to spontaneous hepatocarcinogenesis was detected. The CC57BR mice predisposed to spontaneous hepatomas were insensitive to their induction with o-AAT. The model described may be helpful in studies of the nature of the initiation and promotion stages of hepatocarcinogenesis.

[The phenomenon of cardiomyocyte disappearance in plastic insufficiency of the myocardium]. / Fenomen "ischeznoveniia" kardiomiotsitov pri plasticheskoi nedostatochnosti miokarda.

The anthracycline cytostatic rubomycin hydrochloride was injected into male Wistar rats to induce plastic myocardial insufficiency. Light and electron microscopy and the method of alkaline dissociation of the myocardial tissue to obtain isolated cardiomyocytes were applied to examine the rat heart ventricles under the conditions of suppression of the DNA-dependent RNA synthesis and synthesis of specific proteins. Apart from the involutional processes occurring in the cardiomyocyte cytoplasm resulting in myocardial atrophy, the authors discovered a decrease in the number of muscle cells called "the disappearance phenomenon", since the mechanism of the elimination of a considerable number of cardiomyocytes could not be specified. It was shown that the disappearance of cardiomyocytes in plastic myocardial insufficiency is not linked with necrobiotic or sclerotic alterations.

[Age-related changes in the cardiomyocyte population of the heart ventricles of white rats]. / Vozrastnye izmeneniia populiatsii kardiomiotsitov zheludochkov serdtsa belykh krys.

The total number of muscle cells and their nuclei in the rat ventricle walls at the age from 3 to 30 months was counted by means of alkaline dissociation of the prefixed myocardium. The total number of cardiomyocytes and their nuclei was shown to increase on the second year of life, this increase being much more pronounced and attaining the maximum much earlier in the right ventricle than in the left one. At the senile age (30 months) the number of cardiomyocytes in the ventricles decreases but the mean size of cells increases. Possible sources of replenishment of the population of cardiomyocytes are discussed.

[Stereological analysis of myocardial structures in plastic heart insufficiency]. / Stereologicheskii analiz struktur miokarda pri plasticheskoi nedostatochnosti serdtsa.

Electron microscopy, morphometry and stereological analysis were used to examine structural components of the myocardium of Wistar rats after injection of the anthracycline antibiotic rubomycin. Using the determination of absolute summary weights of cardiomyocytes, interstitial connective tissue, vessels and intercellular space as well as of the volume and surface densities of these structures the development of involutional atrophic lesions in the myocardium was demonstrated. The connective tissue showed an increase in the population of fibroblasts, diffuse activation of protein synthesis in them and collagen synthesis de novo. The genetic relationship between abnormal regeneration of cardiomyocyte ultrastructure (plastic heart insufficiency) and diffusive cardiosclerosis is established.

[Ultrastructural changes in the cardiomyocytes in protein synthesis disorders]. / Ul'ytastrukturnye izmeneniia kardiomiotsitov pri narushenii sinteza belkov.

Electron microscopic study of cardiomyocytes of Wistar rats using an experimental model of myocardial insufficiency induced by injection of rubomycin was carried out. A number of submicroscopic changes occurring in cardiomyocytes when protein synthesis was disturbed (autophagy and sequestration of glycogen, focal cytoplasmic degradation, increased number of secondary lysosomes) were shown to be the structural manifestations of inhibition of RNA synthesis in the nucleus. Alongside with involutional processes, the pathological changes of basic organelles consisting of thinning of myofibrils and decrease of mitochondrial membrane stability were revealed. At the stage of renewal of synthetic processes the dysbalance between intracellular regeneration and abnormalities of new formation of myofibrils was noted. All the observed ultrastructural changes form a morphological basis of development of contractile myocardial plastic insufficiency.

[Morphological types of the changes in the myofibrils of cardiac muscle cells]. / Morfologicheskie tipy izmenenii miofibrill myshechnykh kletok serdtsa.

Light microscopy and electron microscopy examinations showed the changes in myofibrils to be a criterion of early stages of cardiomyocyte involvement. Proceeding from this, the main types of acute cardiomyocyte damage are distinguished: contractures (segmentary and subsegmentary), primary clump degeneration, intracellular myocytolysis and cytolysis. The best way to detect the state of myofibrils by light microscopy is to use polarization microscopy which diagnoses in sections acute metabolic damages and early stages of myocardial infarction, repeated and relapsing infarctions, fibrillation of ventricles. The utilization of polarization microscopy in pathological practice permits one to diagnose definitely the early stages of acute damages of the heart in cases of sudden and unexpected death.

[Stereological study of the absolute total volumes of the structural components of the myocardium in hypertrophy]. / Stereologicheskoe izuchenie absoliutnykh summarnykh ob''emov strukturnykh komponentov miokarda pri gipertrofii.

Wistar rats weighing 200 g were exposed in a low pressure chamber to daily adaptation to altitude hypoxia 8 hours long at an "altitude" of 8000 m. On the 40th experimental day the weight of the left heart ventricle was 41.5% higher as compared to controls. The volumetric and surface density of structural components of the myocardium were determined stereologically by light and electron microscopy, with their absolute total amounts and surfaces being calculated with respect to the ventricle on the whole. The total amount of myofibrila was shown to be steadily increased under hypertrophy, while the amount of mitochondria remained unchanged. However, the total mitochondrial surface augmented in parallel to an increase in the muscular component amount. It is suggested that myofibrillar amount and mitochondrial surface area may be viewed as controllable parameters in heart hypertrophy.

[Formation of transversely oriented myofibrils in myocardiocytes in the presence of heart enlargement]. / Obrazovanie poperechno orientirovannykh miofibrill v miokardiotsitakh pri gipertrofii serdtsa.

Myocardial hypertrophy was induced in rats and mice by training in the pressure chamber (high altitude hypoxia) or ligation of the apex of the heart. Transversely oriented myofibrils developed in the subsarcolemma area of some cardiomyocytes of the ventricles in a fortnight; the Z bands of the newly-formed myofibrils were connected with the T tubules as in the normal myofibrils. It is supposed that this phenomenon was due to the appearance under the sarcolemma of transversely directed mechanical forrces as a result of enlargement of the cell volume.

[Detection of damaged myocardial cells in histological sections by photochemical fluorochroming]. / Vyiavlenia povrezhdennykh kletok miokarda na gistologicheskikh srezakh metodom fotokhimicheskogo fliurookhromirovaniia

The effect of photochemical fluorochromizing used in the method suggested consists in the following: after the exposure of sections to short-wave ultraviolet irradiation the preparations start to fluorescence intensively in the visible region with the long-wave the myocardium of mice, dogs and section materials showed that following photochemical fluorochroming the intensity of lumenescence of damaged cells of the myocardium increased markedly as compared with that of intact cells. The authors recommend to use the described method in diagnosis of early stages of ischemic lesions of the myocardium.

[Early stages of myocardial infarct studied by opitcal methods]. / Rannie stadii éksperimental'nogo infarkta miokarda pri issledovanii opticheskimi metodami

The hearts of 45 dogs were investigated at times from 10 minutes to 24 hours following ligation of the anterior interventricular branch of the left coronary artery. The material was fixed in formalin and embedded in parafin. It was established that at early stages of experimental myocardial infarction in the zone of eschemia there took place eschemic zone various foms of contactural damages, lumpy decmposition, relaxation and sarcoplasmic matrix. By the polarizing microscope method in the peripheral area of the eshemic zone various forms of contractural damages, lumpy decomposition, relaxation and desaggregation of myofibrills, were noted. Phaso-contrast and interference microscopy investigations revealed in the damaged cells an induration of the sarcoplasmic matrix due to an increase in the dry matter concentration. The studies conducted with the help of polarizing, phaso-contrast, and interference microscopy methods showed that by using these methods it is possible at early periods to reveal the zone of myocardial infarction on stained and unstained preparations prepared by conventional methods.

[Morphologic reflection of protein biosynthesis disorders in the myocardial cells of rabbits with acute diphtheritic intoxication]. / Morfologicheskoe otrazhenie narusheniia biosinteza belkov v miokardial'nykh kletkakh krolikov pri ostroi difteriinoi intoksikatsii

The lethal dose of diphtheria toxin (IDLM per 1 kg of body weight) was injected to Chinchilla line adult rabbits. Histological and electron-microscopy investigations were carried out in time periods from 3 to 24 hours following the administration of the toxin. Degenerative and necrotic changes in the myocardial cells under conditions of the given experiment were not observed. In many muscular cells dilatation of the perinuclear spaces due to the thinning of the myofibrila layer moved to the periphery of the cell was noted. Electron-microscopy investigation of the perinuclear spaces showed a decrease in the number of mitochondria, reduction of the elements of sarcoplasmatic reticulum and disappearance of ribosomes. Cytochemically, in the opened cytoplasmatic matrix there were revealed numerous beta-granules of glycogen. In nuclei fragmentation of nucleoli with reduction of their granular component was observed. The changes described justify the conclusion that acute diphtheria intoxication at early stages of exposure to the toxin brings about impairment of the protein synthesis not only at the level of translation on cytoplasmatic ribosomes, as was suggested before, but at the level of ribosome formation in the nucleus as well.

[Cytologic changes in the myocardia of rats trained to altitude hypoxia]. / Tsitologicheskie izmeneniia v miokarde krys, trenirovannykh k vysotnoi gipoksii

Rats trained to the high-altitude hypoxia displayed signs of intensification of both the plastic and lytic processes; one of these processes prevailed in different cells. There was no significant change in the mitochondrial and myofibrillar ratio. An increase of the relative volume of the microcirculatory bed on account of dilatation of small vessels without any increase of their count was noted.

[Preparation of isolated cells by alkaline dissociation of formalin fixed tissue]. / Poluchenie izolirovannykh kletok metodom shchelochnoi dissotsiatsii fiksirovannykh formalinom tkanei

A procedure is described for preparation of isolated cells by treating formaldehyde fixed tissues with a 50%-solution of KOH. This results in complete yield of cells from a variety of organs (liver, kidney, heart, spleen, etc.). The alkali-treated cells entirely retain their morphological and tinctorial peculiarities. It was shown that preparations derived from alkali-treated tissues were useful for a series of quantitative cytological and cytochemical techniques: cytofluorometric estimation of nuclear DNA; interferometric determination of dry cell mass; autoradiographic studies of nuclear DNA synthesis; cell number counts; evaluation of cell distribution according to the number of their nuclei; estimation of the mitotic index.

[The effect of acetylsalicylic acid on the development of infarct-like myocardial necroses experimentally induced in rats by a single administration of novodrin (isopropylnoreadrenaline)]. / Vliianie atsetilsalitsilovoi kisloty na razvitie infarktopodobnykh nekrozov miokarda, vyzyvaemykh v éksperimente na krysakh odnokratnym vvedeniem novodrina (izopropilnoreadrenalina)

It appeared that acetylsalicylic acid considerably decreased both development of the infarction-like foci of necrosis and primary damage of the myocardial cells experimentally induced in animals by direct action of novodrin and expressed in the course of the first hour. This led to the supposition that acetylsalicylic acid not only prevented platelet aggregation, but also increased the resistance of the myocardial cells to the injurious action of catecholamines.

[Focal myofibrillar disorganization in acute metabolic impairment of somatic musculature]. / Ochagovaia dezagregatsiia miofibrill pri ostrykh metabolicheskikh povrezhdeniiakh somaticheskoi muskulatury

Skeletal muscles of rats and rabbits were studied by the target electron microscoptic and polarization-optic methods after administration of toxic substances and experimental acute ischemia of the extremities. Two types of foci of the myofibrillae disaggregation were described along with contracture injuries. The first occurred on the basis of relaxation and was expressed in total dysaggregation and lysis of myofibrillae; with the second type lysis occurred in the partially contracted fibers and began in the I-discs leading to diastasis of A-discs. The first type of the foci is characteristic chiefly of the white fibers, and the second one--of the red.