Relation between glycoprotein synthesis and carbohydrate metabolism in the small intestine mucosa. Effect of cholera enterotoxin

The regulatory properties of adenylate cyclase in small intestinal mucosa were investigated. Glucagon, epinephrine and isoproterenol failed to activate the cAMP synthesis; prostaglandin E1 caused a 2.8-fold, while cholera toxin-a 4.5-fold stimulation. The latter was not able to increase the rate of glucose synthesis from alanine in vitro, but increased markedly the in vivo incorporation of 14C-labeled alanine into the mucus glucosamine. Unlabeled glucosamine excretion was also enhanced 3-fold. This provides evidence for the involvement of glycolysis and gluconeogenesis enzyme systems in the mucosal glycoprotein synthesis. It was assumed that both metabolic pathways may play a common physiological role, namely, to convert carbohydrates and gluconeogenic precursors into the substrate for glucosamine synthesis which is thought to be a rate-limiting step in small intestinal mucus secretion.     

Determination of Staphylococcus species-specific antigens by using erythrocyte reagents

Species-specific (Staphylococcus aureus and S. epidermidis) antigenic and antibody erythrocyte diagnosticums have been prepared. Various tests made with the use of these diagnosticums have demonstrated that the activity of specific antigens is higher in hydrochloric acid extracts than in trichloroacetic and phenolic ones; this activity is linked with undialyzed components and depends on the peculiar features of the strain.     

Effect of the antioxidant dibunol and its combination with phenazepam on the behavior of rats in a conflict situation

The influence of dibunol, phenazepam used alone and combined on rat conflict behavior and rat blood and brain malonic dialdehyde content was studied. It was shown that dibunol exerts an unmarked anticonflict action that can be removed by bicuculline. Combined administration of dibunol and phenazepam potentiates appreciably the anticonflict effect. This permits reducing the doses of the drugs. The anxiolytic effect of dibunol alone and combined with phenazepam is attended by a decrease in the content of malonic dialdehyde in rat blood and brain, evidence of the reduction of the lipid peroxidation intensity.     

Nutritional interaction in an alga-barnacle association

Nitrogen is the major growth-limiting nutrient for marine algae. One potential source of nitrogen for marine algae is ammonium released by invertebrates. Many mid-intertidal reefs in northeastern New Zealand are dominated by a close association between the honeycomb barnacle Chamaesipho columna and an encusting brown alga Pseudolithoderma sp. Growth of Pseudolithoderma was enhanced in the presence of live C. columna, which released ammonium at a greater rate than the maximum rate of ammonium uptake by Pseudolithoderma. Algal tissue on barnacle tests had a lower C:N ratio than tissue located more than 2 cm from the nearest barnacle, suggesting the barnacle is an important source of nitrogen for the alga. The role of nutrient exchange in determining ecological patterns of species in marine communities is discussed.     

Therapeutic effect of the transfusion of UV-irradiated donor plasma in mechanical jaundice

The method of intravenous administration of UV-irradiated donor plasma to patients with jaundice of different genesis has been tested in the experiments on rats and used clinically in 20 patients. Biochemical and morphological studies have shown that such treatment causes stable improvement in the liver functional state.     

Catecholaminergic component of the action of a heptapeptide analog of ACTH4-10 on the open-field behavior of rats

Heptapeptide Met-Glu-His-Phe-Pro-Gly-Pro (ACTH4-10 analog) at a dose of 0.015 mg/kg failed to alter open field behaviour of rats in the first test series. The peptide abolished amphetamine-induced stimulation of the exploratory and grooming behaviour. Extinction of the rats' exploratory behaviour during second test series in the open field (7 days later) was disturbed when haloperidol or apomorphine were injected before the first test series. When the peptide was administered with haloperidol or apomorphine, the extinction tended to become normal. Heptapeptide failed to change noradrenaline, dopamine or 5-hydroxytryptamine content in the rat forebrain. However, this peptide at a concentration of 10(-4) M moderately diminished tyrosine hydroxylation velocity in the rat striatal or hypothalamic synaptosomes, the effect depending on tyrosine concentration. These data suggest the involvement of catecholaminergic component into the heptapeptide action on the behaviour of rats.