Independence of the insulin effect from the guanosine-3',5'-monophosphate level in muscle tissue

The role of cyclic GMP in the insulin effect was investigated using isolated frog sartorii. A study was made of the effect of exogenous cyclic GMP, dibutyryl cyclic GMP, 8-bromo-cyclic GMP on xylose transport, glycogen synthesis and muscle respiration. Only dibutyryl cyclic GMP (1.10(-6) - 10(-4) M) alone was observed to have a stimulating effect on glycogen synthesis and respiration. The xylose transport was but slightly accelerated only following a 20 hours incubation of muscles in the cyclic GMP solution. Cyclic GMP was shown to penetrate the muscle fibres. The cyclic GMP content in muscles was equal to 22.7 +/- 2.0 pM per gram of wet weight. Insulin exerted no effect on cyclic GMP concentration in muscles. The data obtained do not allow to conclude that cyclic GMP may serve as a mediator in realization of the insulin effect on membrane and intracellular processes.     

The strategy of submissive behavior in male mice: the effect of the genotype and the experience of preceding agonistic encounters]

The male mice of two strains with experience of 2 or 10 defeats in intermale agonistic confrontations significantly differ in pattern of submissive behavior (balance of upright and sideways defensive postures, withdrawal, freezing, "on the back" posture). In mice with experience of 20 defeats genetic differences have not been found. The acquisition of consequent experience of defeats does not change the pattern of CBA mice submissive behavior, but significantly increases the share of immobile submissive postures in behavior of C57BL mice. Among submissive males of C57BL strain animals with more active strategy of behavior keep capability for aggressive response to weaker partner. The influence of genotype and previous social contact experience on formation of adaptive in experimental situation strategy of submissive behavior is discussed.     

Dynamic glycogen synthesis in the hepatocytes of different areas of the hepatic lobes in rats

Using image analyser Magiscan, a quantitative analysis of the total glycogen and of its two fractions was made in hepatocytes of portal and central zones of the liver lobule of rats after a 48 hour starvation and 15, 30, 60, 120 minutes after refeeding. Glycogen content was the lowest after a 48 hour starvation and only a few cells of the central zone contained a noticeable glycogen quantity. Glycogen synthesis initiation began 15 minutes after refeeding. Glycogen synthesis is characterized by a higher glycogen content in the portal zone of liver lobule, and further this difference was even more increased. Different changes were observed in the content of glycogen fractions in the process of glycogen resynthesis after starvation of rats.     

The effect of the animals' emotional state on ethanol consumption under free-choice conditions

Voluntary ethanol consumption (20% solution) in mice of C57BL/6J strain with different experience in social agonistic confrontations was studied. It has been shown, that aggressive males daily winning other individuals did not change the level of ethanol consumption, while the submissive mice with daily experience of defeat in intermale encounters dramatically increased that level. Ethanol enhanced the behavioural reactivity of submissive animals to other individuals. It was supposed that emotionally positive or negative states differentiate the ethanol motivations in mice.     

Calixarenes: effects on energy exchange in plant tissues

The distinctive features of the influence of synthetic compounds of a new class, calixarenes, on the energy exchange of the plant tissues and on the ionic permeability of the plant membranes were investigated. Calixarenes of the different chemical structure were shown to sufficiently influence the oxygen consumption by wheat roots, pH of the incubation mixture, and the potassium ions release. Aminomethylated calyx[4]resorcinaren showed the highest effect. The influence of these compounds on the wheat roots was pH dependent.     

Glycogen synthesizing function of hepatocytes in rats with liver cirrhosis after treatment with chorionic gonadotropin]

Using rat liver hepatocytes, methods of cytofluorimetry (Kudryavtseva et al., 1974) and biochemistry were applied to comparative studies of the total glycogen content, including its labile (LF) and stable (SF) fractions, and activities of glucose-6-phosphatase, glycogen phosphorylase and glycogensynthetase in these. The liver hepatocytes were examined in norm, and under conditions of CCl4 poisoning of rats, both 6 months after a chronic poisoning, and 1, 3 and 6 months following poisoning cessation. All the experimentally poisoned rats were divided into two conventional groups: rats of one group received, apart from poisoning, a complex treatment with chorionic gonadotropin (CG); the other group rats received, no treatment. The material used for examination was obtained from serial functional biopsies of each experimental animal. It has been shown that under cirrhosis the content of the total glycogen in hepatocytes increased by 3 times, and that of its SF even by 9.7 times. The treatment with CG for 1 month resulted in its reducing to the norm, and 3 to 6 months treatments normalized contents of both the glycogen fractions. In the group of non-treated rats no similar changes were registered. Besides, in the cirrotic rats the activity of glucose-6-phosphatase was shown to increase by 4 times. After CG treatment it was seen to decrease by 3 times. Thus, CG may be regarded as an optimum and more effective agent for restoring abnormalities in cirrotic liver, compared to some other stimulating factors, such as hepatectomy (Kudryavtseva et al., 1996) or rich-carbohydrate diet (Kudryavtseva et al., 1998).     

Proteolytic cleavage of pertussis toxin S1 subunit is not essential for its activity in mammalian cells

Background  

Pertussis toxin (PT) is an exotoxin virulence factor produced by Bordetella pertussis, the causative agent of whooping cough. PT consists of an active subunit (S1) that ADP-ribosylates the alpha subunit of several mammalian G proteins, and a B oligomer (S2–S5) that binds glycoconjugate receptors on cells. PT appears to enter cells by endocytosis, and retrograde transport through the Golgi apparatus may be important for its cytotoxicity. A previous study demonstrated that proteolytic processing of S1 occurs after PT enters mammalian cells. We sought to determine whether this proteolytic processing of S1 is necessary for PT cytotoxicity.     

Effect of bemythyl on carbohydrate metabolism in cirrhotic rat liver

Effect of actoprotector bemitil (2-ethylthiobenzimidazole hydrobromide) on glycogen content and activities of glycogen synthase, glycogen phosphorylase, and glucose-6-phosphatase was studied in cirrhotically altered rat liver. The contents of glycogen and its fraction were determined a cytofluorimetrically (Kudryavtseva et al., 1974). In cirrhosis, the total glycogen content in hepatocytes increases by nearly 3 times, while the amount of a stable fraction of glycogen rises by 7.5 times. Glucose-6-phosphatase activity fell to the level of 25% compare to the norm. Activities of glycogen synthase and glycogen phosphorylase in the cirrhotic liver did not differ from the norm. In cirrhotically altered liver, bemitil produced a decrease in the total glycogen content due to a decrease in glycogen synthase activity in an increase in glucose-6-phosphatase and glycogen phosphorylase activities. The above results suggest a favorable effect of bemitil on cirrhotic liver.     

Mechanism of action of a novel antitumor preparation of chlofiden. Effect on RNA synthesis

Study of the influence of the antitumor preparation chlofiden on RNA synthesis by sarcoma 45 and liver cells was carried out using 14C-orotic acid. Chlofiden was shown to activate RNA transport from the nucleus to the cytoplasm, and to reduce label incorporation into the nuclear and cytoplasmic RNA. Chlofiden increased the rate of RNA processes, which promoted some increase of label incorporation into low molecular RNA fraction of the nucleus and the cytoplasm. High and stable antitumor activity of chlofiden on sarcoma 45 was established.     

The study of the role of the water medium in the mechanism of action of peptides in low and ultra low doses

The correlation between the structures and conformations of short peptides KE, EW, AEDG and other, their influence on the dynamic properties of water and dose/biologic effect dependencies in a wide range of concentrations were regarded. Their effects on the dynamic properties of water were studied by temperature dependencies (5-45 degrees C) of infrared spectra of the solutions in the near (5180 cm-1) and far (200 cm-1). In vitro biotesting included the determination of the proliferative activity of thymocytes, a bimodal curve with the second maximum were detected at super-low doses (10(-17)-10(-15) mol/l). Authors propose a hypothesis that for superlow concentrations the formation and distance transmission of a signal from ligand to a target cell without the formation of any ligand-receptor complex take place. An active role in this model belongs to water medium acting according to the solution mechanism.