[Aggressive behavior and radiosensitivity in rats'].

This paper aims to present the study of rats' individual radiosensitivity dependence on their individual aggressiveness. On total irradiation in sublethal doses (1.0, 1.5 and 3.5 Gy) and in doses close to LD50/30 (6, 7 and 8 Gy) there was investigated comparative radiosensitivity of non-aggressive and aggressive rats of Wistar line, as well as that of non-aggressive individuals during provoked aggressiveness by means of blocking serotonin synthesis with intraperitoneal (i/p) injection of 400 mg/kg of parachlorphenylalanine (pCPA). Muricidity served as a criterion for aggressiveness and as a criterion of radiosensitivity--cumulative function of survival, the changes of behavior in "Open feald", serotonine and catecholamine content in various brain structures and the dose dependence on the radiation modification of muricidity. It has been found that after 1 Gy total X-irradiation the rats do not lose aggressiveness. Nevertheless the ethalogical parameters change in considerable degree. In the doses of 1.5 and 3.5 Gy muricidity is eluminated in 15-18 and 5-9 days, correspondingly. I/p injection of pCPA after the elimination of aggressiveness provokes transient muricidity in the same terms and duration as it is in case of non-aggressive rats. The elimination of muricidity is associated with changes in content and distribution of biogenic amines in various structures of brain, as well as with reduction of locomotor and reference-research activity, on the one hand and with an increase of emotionality and stereotype activity, on the other hand. After X-irradiation in 6, 7 and 8 Gy the regression coefficients of the dependence of functions type of survival on irradiation dose in aggressive rats is significantly reliable both in comparison with non-aggressive rats and animals with provoked aggressiveness. The change of mortality-rate per unit of changing irradiation dose not depend on blocking of serotonin synthesis, which deficit is one of the distinct determinant of aggressiveness, on the one hand, and higher radiosensitivity, on the other hand. The obtained data allow to suppose that elimination of muricidity after the irradiation of rats in the sublethal doses is conditioned not only by the consequenses of radiation damage of neurobiological structures responsible for the organization of aggressive behavior but the activation of serotonergic system in the process of restitution after radiation trauma. On the other hand, higher radiosensitivity of aggressive rats compared with non-aggressive ones is connected with low serotonin content, thiols and some other biologically active substances which are endogenous radioprotectors determining individual radioresistance.

[Initial heart rate variability and radiosensitivity in rabbits].

The goal of the work was to investigate the rabbits' radiosensitivity dependence on the initial functional state of the autonomous nervous system (ANS), as assessed by time-frequency parameters of the heart rate variability (HRV). Survival rate and rhythm-cardiologic correlates of the pathological processes following total X-irradiation, at doses of 2 and 12 Gy, were studied with an aid of modern computer technologies of measurement and data analysis. It has been found that the animals with initial prevailing of adrenergic influences on the HRV ("sympathicotonics") are significantly more sensitive to irradiation than those in which the parasympathetic prevalence was evident ("vagotonics"). The most characteristic and determining difference between these two groups of animals is initial level of the sum regulatory influences on the heart rhythm, which is manifested in value of total power of spectral density (TP) of HRV. In the sympathicotonics the TP is significantly lower than in the vagotonics. The primary HRV response to irradiation practically does not differ according to the dose and manifests in sharp suppression of the TP in both groups of the animals. At 12 Gy this process is irreversible. In the sympathicotonics it develops earlier and terminates with death much sooner than in the vagotonics. An average life-span of the rabbits, at this dose, is 18.8 +/- 2.6 days in vagotonics, and 10.3 +/- 1.3 days in sympathicotonics (p < 0.02). At 2 Gy initial sharp decrease of the TP in the vagotonics lasts one week only. Then the sum regulatory influence of the ANS on the heart rate increases (rebound) and this condition, which probably points at general resistance of the organism, could be seen within two months; at the end of third month it stabilizes at the initial level. In the sympathycotonics initial sharp decrease of the TP also occurred, however no rebound was observed. The results obtained show that low initial level of the TP of HRV is sufficiently correct marker for higher radiosensitivity in the sympathotonic rabbits against the vagotonic ones.

Effects of low ethanol doses on heart rhythm in rabbits.

Effects of low ethanol doses on the vagosympathetic mechanisms of heart rhythm regulation were studied in rabbits. Analysis of heart rhythm variability showed that single intragastric administration of 0.5 mg/kg ethanol caused tachycardia in animals with initial predominance of vagal activity and bradycardia in animals with predominating sympathetic mechanisms. This was associated with general activation of all regulatory effects on the heart rhythm and a drastic increase in power spectrum for all frequency ranges, though with a certain deficiency of vagal effects. However, after 24 h the vagal component of the spectrum drastically increased in animals of both groups, while other parameters did not differ from the control. Presumably, this rebound can be used as a physiological marker, ethanol tolerance measure, formation of the abstinence syndrome and liability to alcoholism.

Heart rate variability in Chinchilla rabbits.

Temporal and spectral parameters of heart rate variability were studied as criteria for classification of mature Chinchilla rabbit population according to their basal neurovegetative status. The absolute values of total spectral power density and individual frequency bands differed significantly in vagotonics and sympathotonics. However, standardized spectral power distributions in high-, low- and very low-frequency ranges were similar in both groups. Our results suggest that the intensity of regulatory influences on the heart at all levels of regulation, which can be evaluated by spectral analysis, is similarly distributed in both groups. Hence, the observed differences in the heart rate variability can not be explained by peculiarities in sympathovagal balance, but are determined by more universal mechanisms.

[Blastocoele potential in the early frog embryo]. / Potentsial blastotselia rannego zarodysha liagushki.

The resistance of intercellular gaps between the blastomeres and the potential of the blastocoel cavity in the cleaving frog eggs were estimated by means of microelectrode technique. The maximal and minimal values of these parameters were evaluated in different phases of the mitotic cycle.

[Properties of globular protein monolayers at physiological temperature intervals]. / Svoistva monosloev globuliarnykh belkov v fiziologicheskom intervale temperatur.

The dynamics of changes in monolayer (MML) static and kinematic characteristics of some globular proteins (humans' serum, albumin, actin, cytochrome c) was studied. Two series of experiments were carried out: 1) formation of MML at the stable temperature of subphase 12, 23 and 32 degrees C; 2) formation of MML at 12 degrees C and equilibrium warming up and following cooling of subphase with MML in the temperature interval of 12-34 degrees C. In the cooling-warming up cycle the dependence of MML surface pressure change on the temperature was found to have the form of reserved loop hysteresis with the minimum at 21 +/- 2 degrees C on warming up branch. By the following rise of temperature up to reaching the plateau (26 degrees C) the entropy of monolayer takes the negative meaning. On the branch of cooling loop such transition is not seen. These data indicate possibility of trigger conformative changes of protein molecules, which in situ condition can occur during the natural local (metabolic) temperature gradients in living cells and influence the functional specificity of protein molecules and their bioorganic complexes.

[Postradiation changes in the activity of membrane-bound nerve tissue enzymes]. / Postradiatsionnye izmeneniia aktivnosti membranosviazannykh fermentov nervnoi tkani.

A study was made of the effect of various radiation doses (1.75 to 12.25 Gy) on the enzyme activity of Na,K-ATPase system of the microsomal brain fraction of mongrel and Wistar rats. With a similar method of the fraction isolation different response of the activity of this enzyme was registered. Different radiosensitivity of M9-ATPase is responsible for the direction of changes in the Na,K-ATPase activity of the preparations.

[The radiomodifying action of ATP and ADP on membrane-bound enzymes]. / Radiomodifitsiruiushchee deistvie ATF i ADF na membranosviazannye fermenty.

A modifying action of ATP and ADP on the activity of some key membrane-bound enzymes of the brain and heart microsomes of rats exposed to 7 Gy radiation has been investigated. The difference in the reactions of energy-dependent enzymes is attributed to the compensatory systems involved at the molecular level.

[Interaction of acetylcholine and tubocurarine with protein molecules of the actin complex and phosphatidylcholine]. / Vzaimodeistvie atsetilkholina i tubokurarina s molekulami belkov aktinovogo kompleksa i fosfatidilkholina.

By means of surface Wilhelmi weight type changes of monomolecular layer properties of some proteins and lipids at the air--water boundary have been studied during acetylcholine and tubocurarine injection in the subphase. Active interaction of acetylcholine and tubocurarine molecules with monolayers of actin, myosin and phosphatidylcholine was observed, while the properties of human serum albumin (HSA) and cholesterine were not influenced by the same physiologically active substances. These substances had no effect on the area of monolayers and on other physico-chemical parameters of HSA and cholesterine. On the other hand when acetylcholine is present in the subphase of phosphatidylcholine monolayer the velocity of HSA penetration in these monolayers in sharply decreased.