Classification of the follicle population based on oocyte diameter and number of granulosa cells in the ovary of large-eared hedgehog, Hemiechinus auritus gmelin

The present study includes the classification of ovarian follicle population in H. auritus on the basis of oocyte diameter and granulosa cell layers. Our observations revealed that there was direct relationship in the oocyte diameter and the follicle size under a certain limit. Diameter of oocytes increased from 10 microns to 84 microns with consequent increase in the follicle size from 20 microns to 320 microns. However, the diameter of oocyte did not show further increase, but the follicle size was enlarged gradually up to 500 microns. Based on the diameter of follicle and the number of granulosa cell layers, the follicle population was divisible into 5 categories: 1. primordial follicle which ranged 20 to 80 microns in diameter with few cells to one complete layer of granulosa cells in the largest cross section; 2. small follicle which was 81 to 200 microns in diameter having 2 to 3 complete layers of granulosa cells; 3. secondary or medium-sized follicle which ranged 201 to 320 microns in diameter and consisted of 4 to 6 complete layers of granulosa cells; 4. transitory follicle having diameter 321 to 360 microns and 7 complete layers of granulosa cells; 5. large-sized follicle which ranged 361 to 500 microns in diameter and had more than 7 layers of granulosa cells.     

Two classes of gating current from L-type Ca channels in guinea pig ventricular myocytes.

Intramembrane charge movement was recorded in guinea pig ventricular myocytes at 19-22 degrees C using the whole-cell patch clamp technique. From a holding potential of -110 mV, the dependence of intramembrane charge moved on test voltage (Q(V)) followed the sum of two Boltzmann components. One component had a transition voltage (V) of -48 mV and a total charge (Qmax) of congruent to 3 nC/microF. The other had a V of -18 mV and a Qmax of 11 nC/microF. Ba2+ currents through Ca channels began to activate at -45 mV and peaked at congruent to -15 mV. Na+ current peaked at -35 to -30 mV. Availability of charge (in pulses from -70 to +10 mV) depended on the voltage of conditioning depolarizations as two Boltzmann terms plus a constant. One term had a V of -88 mV and a Qmax of 2.5 nC/microF; the other had a V of -29 mV and a Qmax of 6.3 nC/microF. From the Q(V) dependence, the voltage dependence of the ionic currents, and the voltage dependence of the availability of charge, the low voltage term of Q(V) and availability was identified as Na gating charge, at a total of 3.5 nC/microF. The remainder, 11 nC/microF, was attributed to Ca channels. After pulses to -40 mV and above, the OFF charge movement had a slow exponentially decaying component. Its time constant had a bell-shaped dependence on OFF voltage peaking at 11 ms near -100 mV. Conditioning depolarizations above -40 mV increased the slow component exponentially with the conditioning duration (tau approximately equal to 480 ms). Its magnitude was reduced as the separation between conditioning and test pulses increased (tau approximately equal to 160 ms). The voltage distribution of the slow component of charge was measured after long (5 s) depolarizations. Its V was -100 mV, a shift of -80 mV from the value in normally polarized cells. This voltage was the same at which the time constant of the slow component peaked. Qmax and the steepness of the voltage distribution were unchanged by depolarization. This indicates that the same molecules that produce the charge movement in normally polarized cells also produce the slow component in depolarized cells. 100 microns D600 increased by 77% the slow charge movement after a 500-ms conditioning pulse. These results demonstrate two classes of charge movement associated with L-type Ca channels, with kinetics and voltage dependence similar to charge 1 and charge 2 of skeletal muscle.(ABSTRACT TRUNCATED AT 400 WORDS)     

Sodium-coupled motility in a swimming cyanobacterium.

The energetics of motility in Synechococcus strain WH8113 were studied to understand the unique nonflagellar swimming of this cyanobacterium. There was a specific sodium requirement for motility such that cells were immotile below 10 mM external sodium and cell speed increased with increasing sodium levels above 10 mM to a maximum of about 15 microns/s at 150 to 250 mM sodium. The sodium motive force increased similarly with increasing external sodium from -120 to -165 mV, but other energetic parameters including proton motive force, electrical potential, the proton diffusion gradient, and the sodium diffusion gradient did not show such a correlation. Over a range of external sodium concentrations, cell speed was greater in alkaline environments than in neutral or acidic environments. Monensin and carbonyl cyanide m-chlorophenylhydrazone inhibited motility and affected components of sodium motive force but did not affect ATP levels. Cells were motile when incubated with 3-(3,4-dichlorophenyl)-1,1-dimethylurea and arsenate, which decreased cellular ATP to about 2% of control values. The results of this investigation are consistent with the conclusion that the direct source of energy for Synechococcus motility is a sodium motive force and that below a threshold of about -100 mV, cells are immotile.     

Change in the electrophysiological parameters of rat oocytes maturing in vivo

The membrane potential (MP) and input membrane resistance (R) were measured in the immature (1) and mature ovulated (2) rat eggs. The population 1 is homogeneous enough: in 78.3% of all oocytes MP equaled --18 +/- 0.3 mV and R = 3 +/- 0.6 mO; 21.7% of cells had MP = --2 +/- 0.9 MV and R = 3.5 +/- 0.6 mO. The population 2 was divided by the indices under study into 4 groups. The respective values of MP and R in each of 4 groupd 5.5 +/- 0.5 mO, c) --15 +/- 0.6 mV and 7 +/- 1.0 mO, d) --3 +/- 0.4 mV and 9 +/- 0.5 mO. A suggestion is put forward that MP and R of the oocytes change with respect to the maturation stage.     

Variability of the cardiomyocyte ploidy in normal human hearts.

We have performed cytophotometry for DNA in isolated myocytes of the left ventricle from 16 men, aged 19-39 years, who died from various non-cardiac or pulmonary causes. The mean ploidy of myocytes varied from 3.2-3.9 c to 6.6-7.3 c in different layers of the anterior wall of the left ventricle (where c is the haploid DNA content measured by cytophotometry in Feulgen-stained preparations). There was no correlation between the layers. The percentage of binuclear cells varied from 25 to 86% and correlated in every layer with the mean ploidy value of the whole myocyte population. Approximate calculation of total ploidy revealed low values in the ventricles of some individuals, and high values in others. Averaging the values for all the hearts studied obscures this variation. Mean myocyte ploidy in different layers of the anterior wall was similar: in the external layer it was 5.1 +/- 0.3 c, in the middle layer 5.5 +/- 0.3 c and in the inner layer 4.8 +/- 0.4 c. The mean percentage of binuclear myocytes in these three layers was also similar, being 61 +/- 3%, 63 +/- 4% and 54 +/- 5%, respectively. Myocyte ploidy in tissue from the posterior wall of the left ventricle also varied, but was always higher than for the same layer of the anterior wall in the same ventricle. We propose that high or low myocyte ploidy, as well as different proportions of mono- and binucleate cells, can be a factor affecting the course and result of cardiac pathology in the absence of any changes of myocyte genome determined during early ontogenesis and representing a stable characteristic of the individual.     

Membrane Potential of Cultured Carrot Cells in Relation to the Synthesis of Anthocyanin and Embryogenesis

Membrane potentials of cultured carrot cells in culture mediumwere about –40 mV and did not change with addition ofsalts of addition (or depletion) of 2,4-dichlorophenoxyaceticacid (2,4-D). When the measurement was performed in the testmedium (containing low concentration of salts), the values werewidely distributed (from –60 to –110mV) and changedlargely with external concentration of K⁺ but not Mg²⁺ nor Ca²⁺.When the cells were fractionated by Ficoll density gradientcentrifugation, the membrane potential of the cells of higherdensity (> 14% Ficoll) was about –150 mV in the testmedium and did not change during embryogenesis with depletionof 2,4-D. The membrane potential of cells of lower density (bandingbetween 6– 10% Ficoll) was less negative (– 60 to– 110 mV) in the test medium. When these cells were transferredand cultured in medium containing zeatin but lacking 2,4-D,the membrane potential was shifted negatively by about 15 mVprior to anthocyanin synthesis. When 2,4-D was added to anthocyanin-synthesizingcells in the medium containing zeatin, a transient hyperpolarizationand subsequent depolarization of the membrane were observedprior to the inhibition of anthocyanin synthesis. (Received October 22, 1987; Accepted April 20, 1988)     

The extracellular matrix of the cuticle of Gordius panigettensis (Gordioiidae,Nematomorpha): observations by TEM,SEM and AFM

The cuticle of Gordius panigettensis (Sciacchitano, 1955) was studied by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and atomic force microscopy (AFM). The cuticle is composed of 30-50 compact layers. The number of the layers is higher in the central part of the animal's body and decreases at the extremities. Each layer is composed of parallel tightly packed fibres approximately 640 nm in diameter and of indefinite length. The fibres run strictly parallel within each layer, while in adjoining layers they run at a variable angle from 45 degrees in the central body to 90 degrees in the extremities. Each fibre shows a barely detectable filamentous inner structure and is enveloped in a thin highly regular net formed by hexagonal meshes. Our results suggested that these fibres should be proteinaceous although non-collagenous. Thinner radial fibres run among the large fibres and across all the layers and span the whole thickness of the cuticle from the epithelial layer located deep underneath the large fibres up to the epicuticle on the external surface of the animal.     

Characteristics of the functional properties of the spinal cord motoneurons of old rats]

The mean membrane potential (MP) of old rats did not differ significantly from that in young mature rats ((58.4 +/- +/-1,4 mV and 56.6 +/- 1.26 mV, respectively). At the same time the frequency of detection of motor neurons with the MP OF 70 mV and more fell by 18.6%, and with the MP of 50-59 mV -increased by 14.2% in the old, in comparison with the young animals. The direct excitability threshold in old rats decreased (3.0 +/- 3-10(-9) in young mature and 2.0 +/- 0.2-10(-9) a in old rats; P less than 0.02). The number of discharges per 50 msec of the neuron poliarization reached 4-5, constituting 80-100 pulse/min. When determined by the first two intervals the action potential frequency reached 125 pulse/sec, and in the young mature rats--over 300 pulse/sec. The duration of antidromic spikes was increased (1.02 +/- 0.09 msec in young mature animals and 1.65 +/- 0.14 msec in the old animals; P less than 0.001). The antidromic spikes of the neurons in old mature rats, as a rule, had no delayed depolarization.     

Blubber morphology in wild bottlenose dolphins (Tursiops truncatus) from the Southeastern United States: influence of geographic location, age class, and reproductive state

This study investigated blubber morphology and correlations of histological measurements with ontogeny, geography, and reproductive state in live, wild bottlenose dolphins (Tursiops truncatus) from the southeastern United States. Surgical skin-blubber biopsies (N=74) were collected from dolphins during capture-release studies conducted in two geographic locations: Charleston, SC (N=38) and Indian River Lagoon, FL (N=36). Histological analysis of blubber revealed stratification into superficial, middle, and deep layers. Adipocytes of the middle blubber were 1.6x larger in Charleston subadults than in Indian River Lagoon subadults (4,590+/-340 compared to 2,833+/-335 microm2 per cell). Charleston subadult dolphins contained higher levels of total blubber lipids than Charleston adult animals (49.3%+/-1.9% compared to 34.2%+/-1.7%), and this difference was manifested in more adipocytes in the middle blubber layer (19.2+/-0.9 compared to 14.9+/-0.5 cells per field). However, dolphins from Indian River Lagoon did not exhibit this pattern, and the adipocyte cell counts of subadults were approximately equal to those of the adults (16.0+/-1.4 compared to 13.4+/-0.8 cells per field). The colder year-round water temperatures in Charleston compared to Indian River Lagoon may explain these differences. Adipocytes in the deep blubber layer were significantly smaller in lactating and simultaneously pregnant and lactating animals compared to pregnant dolphins (840+/-179, 627+/-333, and 2,776+/-586 microm2 per cell, respectively). Total blubber lipid content and adipocyte size in the deep blubber of mothers with calves decreased linearly with calf length. Lactating females may utilize lipids from the deep blubber during periods of increased energetic demands associated with offspring care. This study demonstrates that ontogeny, geography, and reproductive state may influence morphological parameters such as structural fiber densities and adipocyte numbers and sizes, measured in bottlenose dolphin blubber.     

Effects of combined influence of ionizing radiation and light on the retina

The continuous irradiation of rats with a light (3500 1x) for 48 hours led to destruction of 7.5 +/- 0.43% of neurosensoric cells (the control value was 0.2 +/- (0.02%). Longer photodamage caused progressing decrease in a population of the cells, narrowing followed by disappearance of corresponding layers of retina by the 30th day of the experiment. Preliminary exposure to X-rays with a dose of 5 Gy modified light damages of retina. The combination of two factors caused death of more than 30% of neurosensoric cells and redused the number of rows of nucleis of the external nuclear layer twice for the first 48 hours of illumination. After a longer influence of light a preliminary ionizing irradiation increased the number of destructively changed neurosensoric cells, reaching minimun of 41.7% by 30th day of the experiment. At the same time after a long combined irradiation less changes in row number quantity, numerical density of nucleus of the external nuclear layer and a population of neurosesoric cells in general was observed than after only one light exposure. Changes of choriocapillaries (thrombosis, obliteration, narrowing of a gap) which were more expressed at a combination of factors, led to infringement of blood circulation and played the important role in mechanisms of retina degeneration. Radial glia and neurons of internal layers of retina showed relative resistance to the investigated influences.     

Morphology and electrical properties of Schwann cells around the giant axon of the squids Loligo forbesi and Loligo vulgaris.

The first successful dye-fills of Schwann cells around the split giant axon of Loligo show them to be spindle-shaped cells ca. 600 microns long and 20 microns wide lying parallel to the axonal axis. There are some 50,000 Schwann cells per cm2 of axonal membrane. Only a small part (ca. 6% of each Schwann cell membrane) is in contact with the periaxonal space, the remainder is overlain by adjacent Schwann cells, or applied to the basal lamina. The mean membrane potential of the Schwann cells in artificial seawater (ASW) varies from around -40 mV in fresh split-axon preparations to around -60 to -70 mV after 1-2 h; this hyperpolarization is not seen in preparations dissected and maintained in Ca2(+)-free ASW. Electrical- and dye-coupling (abolished by prior octanol treatment) is present between Schwann cells, but is weaker in cells with lower (less negative) membrane potentials. The implications for potassium homeostasis around the axon are briefly discussed.     

Membrane potential of rat calvaria bone cells: dependence on temperature

The membrane potentials of bone cells derived from calvaria of new born rats was shown to be strongly dependent on temperature. When we lowered the temperature from 36 degrees C to 26 degrees C, cells with spontaneous resting membrane potentials (MP) of -80 to -50 mV depolarized (mean amplitude 8 mV; n = 33), and the membrane resistance increased by approximately 80% (n = 20). The temperature response depended on the actual MP, the reversal potential being in the range of -80 to -90 mV. With the application of ouabain (0.1-1 mmol/liter; n = 12), cells depolarized. Simultaneously, the reversal potential of the temperature response was shifted towards more positive values and approached the actual MP level of the cells. Consequently, the depolarization amplitudes induced by lowering temperature were reduced at spontaneous MP levels. The rise of the membrane resistance during cooling was unaffected. When the extracellular chloride concentration was reduced from 133 to 9 mmol/liter, temperature-dependent depolarizations persisted at spontaneous MP values (n = 5). The findings indicate that the marked effects of temperature changes on the MP of bone-derived cells are mainly determined by changes of the potassium conductance.     

Hypoxia-induced activation in small isolated pulmonary arteries from the cat

Effects of hypoxia on force development and membrane potential were studied in isolated small (less than 300 microns diam) and large (greater than 500 microns diam) pulmonary arteries from cats. There was a consistent and reproducible hypoxic constrictor response in small pulmonary arteries that began at PO2 values between 350 and 300 Torr and reached a maximum at PO2 between 50 and 30 Torr. In the small artery smooth muscle cell the membrane potential, which was -51 +/- 1.4 mV at a PO2 of 400 Torr, was depolarized to -37 +/- 2 mV at a PO2 of 50 Torr. In contrast, larger arteries did not exhibit significant hypoxic constriction or depolarization upon exposure to low PO2. Constriction in small arteries was not blocked by phentolamine. Treatment with a low dose of indomethacin (10(-9) M) augmented the response; however, a larger dose of indomethacin (10(-3) M) blocked the constriction to hypoxia but not to 30 mM KCl. Depolarization during hypoxia was not blocked by ouabain. Results of this study suggest that the hypoxic response of these isolated small pulmonary vessels may be like that seen in the intact lung. Furthermore, these data suggest that hypoxic vasoconstriction may be mediated by electrical events occurring at the pulmonary arterial muscle cell membrane either directly or via mediators released from the vessel wall.     

Membrane transport in stomatal guard cells: The importance of voltage control

Potassium uptake and export in the resting conditions and in response to the phytohormone abscisic acid (ABA) were examined under voltage clamp in guard cells of Vicia faba L. In 0.1 mM external K+ (with 5 mM Ca2(+)-HEPES, pH 7.4) two distinct transport states could be identified based on the distribution of the free-running membrane voltage (VM) data in conjunction with the respective I-V and G-V relations. One state was dominated by passive diffusion (mean VM = -143 +/- 4 mV), the other (mean VM = -237 +/- 10 mV) exhibited an appreciable background of primary H+ transport activity. In the presence of pump activity the free-running membrane voltage was negative of the respective K+ equilibrium potential (EK+), in 3 and 10 mM external K+. In these cases VM was also negative of the activation voltage for the inward rectifying K+ current, thus creating a strong bias for passive K+ uptake through inward-rectifying K+ channels. In contrast, when pump activity was absent VM was situated positive of EK+ and cells revealed a bias for K+ efflux. Occasionally spontaneous voltage transitions were observed during which cells switched between the two states. Rapid depolarizations were induced in cells with significant pump activity upon adding 10 microM ABA to the medium. These depolarizations activated current through outward-rectifying K+ channels which was further amplified in ABA by a rise in the ensemble channel conductance. Current-voltage characteristics recorded before and during ABA treatments revealed concerted modulations in current passage through at least four distinct transport processes, results directly comparable to one previous study (Blatt, M.R., 1990, Planta 180:445) carried out with guard cells lacking detectable primary pump activity. Comparative analyses of guard cells in each case are consistent with depolarizations resulting from the activation of an inward-going, as yet unidentified current, rather than an ABA-induced fall in H(+)-ATPase output. Also observed in a number of cells was an inward-directed current which activated in ABA over a narrow range of voltages positive of -150 mV; this and additional features of the current suggest that it may reflect the ABA-dependent activation of an anion channel previously characterized in Vicia guard cell protoplasts, but rule out its function as the primary mechanism for initial depolarization.(ABSTRACT TRUNCATED AT 400 WORDS)     

Oxygen sensing by ion channels and chemotransduction in single glomus cells

We have monitored cytosolic [Ca2+] and dopamine release in intact fura- 2-loaded glomus cells with microfluoroimetry and a polarized carbon fiber electrode. Exposure to low PO2 produced a rise of cytosolic [Ca2+] with two distinguishable phases: an initial period (with PO2 values between 150 and approximately 70 mm Hg) during which the increase of [Ca2+] is very small and never exceeds 150-200 nM, and a second phase (with PO2 below approximately 70 mm Hg) characterized by a sharp rise of cytosolic [Ca2+]. Secretion occurs once cytosolic [Ca2+] reaches a threshold value of 180 +/- 43 nM. The results demonstrate a characteristic relationship between PO2 and transmitter secretion at the cellular level that is comparable with the relation described for the input (O2 tension)output (afferent neural discharges) variables in the carotid body. Thus, the properties of single glomus cells can explain the sensory functions of the entire organ. In whole-cell, patch- clamped cells, we have found that in addition to O2-sensitive K+ channels, there are Ca2+ channels whose activity is also regulated by PO2. Ca2+ channel activity is inhibited by hpoxia, although in a strongly voltage-dependent manner. The average hypoxic inhibition of the calcium current in 30% +/- 10% at -20 mV but only 2% +/- 2% at +30 mV. The differential inhibition of K+ and Ca2+ channels by hypoxia helps to explain why the secretory response of the cells is displaced toward PO2 values (below approximately 70 mm Hg) within the range of those normally existing in arterial blood. These data provide a conceptual framework for understanding the cellular mechanisms of O2 chemotransduction in the carotid body.     

Observations on the morphology of Toxocara pteropodis eggs

Fertile eggs of Toxocara pteropodis, passed in the faeces of juvenile flying-foxes, were ovoid to spheroid in shape with a diameter range of 80-110 microns. The shell was often seen to comprise 4 layers: a fine inner lipid layer, a thicker clear chitinous layer, an equally thick outer vitelline layer and a pitted outermost, proteinaceous uterine layer of variable thickness. Infertile eggs were less uniform in shape and generally did not have well-defined shell layers, the formation of which is triggered by sperm penetration of the oocyte. The eggs of this species are bulkier than those of related ascaridoids, apparently because of a thicker external coat which, while not providing mechanical strength, is thought to protect against desiccation. Scanning electron microscopical findings suggest that the outer layer is not applied directly by uterine cells, but forms by the gradual deposition of secretions in the uterine lumen, regardless of whether the oocyte has been fertilized.     

离体培养小鼠神经细胞在有丝分裂过程中的膜电位变化（简报）

Primarily cultured dorsal root ganglion cells and olfactory bulb cells were dissected from 12 to 14-d-old fetal C57 BL/6 J mice. After the cells were cultured for about two weeks, the growing status of cells were observed and the membrane potentials(MP) were recorded. The results show that mean value of the MP in anaphase was -68 +/- 3.1 mV (SE, n = 3), same as in interphase: Beginning from telophase, the cell membrane in the equator contracted gradually to become a concave ditch, and the MP decreased obviously, the mean value was -23.3 +/- 3.3 mV (SE, n = 6). After this, MP recovered gradually, till it divided into two sister cells. MP which were recorded separately in two sister cells were similar. But usually MP did not recovered to their normal values immediately.     

夏季鄂霍茨克海公海区狭鳕渔场环境特征

根据鄂霍茨克公海区狭鳕资源声学评估调查资料,研究了狭鳕分布状况及渔场环境特征,并分析了狭鳕行动分布与环境的关系．结果表明,8月公海区狭鳕密集群位于55°N以北、水深小于500m的海域,其主要分布水层在150～300m之间;调查期间狭鳕只为索饵群体,主要摄食太平洋磷虾,狭鳕密集区一般也为太平洋磷虾高密度分布区;8月公海区水温跃层大致在0～50m之间,强度为0．25℃     

Electron microscopy of the medial cortex in the lizard Psammodromus algirus

The medial cortex of Psammodromus presents a three-layer organization. Most of the cell bodies are localized in a compact lamina, the cellular layer. Two plexiform layers, superficial and deep, enclose the cellular layer. The most external portion of the superficial plexiform layer is formed by a limiting glial sheet consisting of tanycytic processes that reach the surface of the cortex. Astrocytes are localized close to the glial sheet. There are two types of axon terminals within the superficial plexiform layer: type S with spheric vesicles and type F with pleomorphic vesicles. Large solitary neurons are present at middle levels of the layer. In the cellular layer there are three neuronal types: large neurons with dispersed chromatin, neurons of medium size with chromatin clumps, and electron-dense neurons. Protoplasmic astrocytes are found superficially in this layer. In the deep plexiform layer numerous neuronal cell bodies are visible, and three types can be distinguished: horizontal fusiform cells, globous neurons with indented nuclei, and electron-dense neurons. Protoplasmic astrocytes are present throughout this layer. Oligodendrocytes are more frequent in the inner third of the layer, often related to fibers of a thick fascicle running in contact with the ependyma, the alveus. The ependyma is formed by a single row of prismatic cells bordering the lateral ventricle.     

Variability of the cardiomyocyte ploidy in normal human hearts

We have performed cytophotometry for DNA in isolated myocytes of the left ventricle from 16 men, aged 19–39 years, who died from various non-cardiac or pulmonary causes. The mean ploidy of myocytes varied from 3.2–3.9 c to 6.6–7.3 c in different layers of the anterior wall of the left ventricle (where c is the haploid DNA content measured by cytophotometry in Feulgenstained preparations). There was no correlation between the layers. The percentage of binuclear cells varied from 25 to 86% and correlated in every layer with the mean ploidy value of the whole myocyte population. Approximate calculation of total ploidy revealed low values in the ventricles of some individuals, and high values in others. Averaging the values for all the hearts studied obscures this variation. Mean myocyte ploidy in different layers of the anterior wall was similar: in the external layer it was 5.1±0.3 c, in the middle layer 5.5±0.3 c and in the inner layer 4.8±0.4 c. The mean percentage of binuclear myocytes in these three layers was also similar, being 61±3%, 63±4% and 54±5%, respectively. Myocyte ploidy in tissue from the posterior wall of the left ventricle also varied, but was always higher than for the same layer of the anterior wall in the same ventricle. We propose that high or low myocyte ploidy, as well as different proportions of mono- and binucleate cells, can be a factor affecting the course and result of cardiac pathology in the absence of any changes of myocyte genome determined during early ontogenesis and representing a stable characteristic of the individual.