Morphogenetic processes and seasonal changes in the anatomic and histological organization of the Barents Sea sponge Halichondria panicea (Pallas)

As a result of histological investigations of seasonal dynamics in the anatomical-tissue organization of the litoral sponge Halichondria panicea (Pallas), morphogenetical processes during different periods of its life cycle are described in detail. Correlations between different phases of sexual reproduction and conditions of anatomical and tissue organization in the maternal organism are stated. It is noted that tissue reduction of the definitive sponge Halichondria panicea during autumn--winter season is a natural phenomenon, regularly repeating in the life of the litoral sponge investigated, as a result of the maternal organism's "exhaustion" in the period of sexual embryogenesis.     

Changes in the activity of the supraoptic nuclei of the hypothalamus and distal portions of the hypothalamo-hypophyseal neurosecretory system of guinea pigs under the influence of high environmental temperature]

The keeping of guinea pigs in a thermochamber at 37 degrees C for 3 days resulted in increased releasing of neurohormones of the posterior lobe of the hypophysis. By the end of the 3d day there was no substantial difference between the average logarhythm of the volume of cell nuclei of the supraoptic nucleus of experimental animals and that of intact animals. Injection of ACTH after a preliminary three-day presence of the animal in the thermochamber caused a pronounced inhibition of the hypothalamo-hypophyseal neurosecretory system (HHNS). The HHNS of animals subjected to 3-day-long continuous exposure to high temperature, in contrast to the HHNS of intact animals is not capable to increase its activity in responses to stress (immobilization).     

Study of the interaction of polyols with polymers containing n-substituted [(4-boronophenyl)methyl]-ammonio groups

Polymers, based on dextran and cellulose, having 2-{[(4-boronophenyl)-methyl]-ethylammonio}ethyl and -diethylammonio～ethyl groups were prepared. It was shown that these polymers could be employed for absorption of cis-diol compounds. The polymers were found to be highly specific towards polyols, carbohydrates, nucleosides, and nucleotides over a wide range of pH. The polymer based on DEAE-Sephadex A-25 was used in separating nucleosides, and in fractionating mononucleotides and carbohydrates. The chromatographic behavior of carbohydrates is defined by their structure and conformation, which are also responsible for different stabilities of the boronic complexes generated.     

Pharmacological analysis of slow potentials recorded in forg olfactory bulb during natural stimulation

Pharmacological agents (strychnine, picrotoxin, pentobarbital, chloralose, GABA, penicillin, morphine) were used to investigate the nature of the slow potential recorded in the frog olfactory bulb in response to natural stimulation. Three possible hypotheses were tested: 1) The slow potential is neuroglial in nature; 2) it is the analog of the dorsal-root potential of the spinal cord and reflects depolarization of primary afferents arising in the terminals of the olfactory nerve and responsible for presynaptic inhibition in the frog olfactory bulb; 3) the slow potential reflects postsynaptic processes. The results showed great similarity between changes in the slow and dorsal-root potentials of the spinal cord in response to the action of pharmacological agents. However, the slow potential is evidently a complex response and incorporates at least one other component — depolarization of the dendrites of unknown nature.     

Absorption of testosterone-7 alpha-3H by tissues of organ-targets in male rat embryos]

The dynamics of consumption of testosterone-7alpha-3H by different tissues of the differentiating reproductive system, as well as by suprarenals, brain, hypothalamus and muscles was studied in the in vivo experiments with the rat male embryos beginning from the 14th and till the 20th days of development. The specific consumption of the labelled androgen related to the metabolic processes was observed at all developmental stages under study. The selective consumption of testosterone-7alpha-3H was noted prior to the beginning and during the morphogenesis of the organs-targets' rudiments. The radioactivity in tissues increased already 1--2 days following the castration of 18 days old embryos. Estrone, testosterone, testosterone-propionate, cyproterone-acetate competitively decreased the consumption of testosterone-7alpha-3H. The problem of reception of tissues of the rat male embryos to the male sex hormone is discussed.     

Effect of different doses of ethanol on the release of enzymes and lipids from the perfused rat liver

The perfusion in situ of the rat liver reveals appearance of enzymes of different subcellular localization, potassium ions and lipid components in the perfusate. Ethanol introduction at different doses induces the most expressed changes in the activity of catalase, lactate dehydrogenase, arginase and alanine aminotransferase and in the potassium removal from hepatocytes. A degree of the evoked changes depends on the dose.