Thio-urea and methionine effects on glucose and leucine absorption in chicken jejunum.

Administration to broiler chickens of one single dose of thio-urea (7 mg/kg body weight) on the 7th day of age affects in different ways jejunal absorption of glucose and of leucine. Methionine supplementation of feedstuff (1.5 g/kg) through 40 days affects, in an age-dependent manner, glucose absorption, but not that of leucine.

Effects of dietary protein deficiency on hepatic carbohydrate metabolism in geese.

This paper was aimed at following up the course of glucose in the liver of protein underfed geese. Compared to normally fed geese, liver carbohydrate metabolism in protein underfed animals can be characterised by lowering of free glucose content of in vitro glucose uptake and glycogen synthesis and reduction of carbohydrates in total oxidation. Glycogen content of the liver and rate of glucose oxidation were also lowered, but these differences were not statistically significant.

Biochemical energetics of hierarchy formation in Betta splendens.

Two different stages of hierarchy formation in Betta splendens were considered. Winners and losers in a short social contact, and dominant and submissive individuals after the establishment of a hierarchy, respectively, were identified. Metabolical determinations (free glucose, glycogen and protein content, glycogen and protein synthesis, glucose and amino acid oxidation, carbohydrate degradation) were performed.

Proline requirement for glucose utilization by Peptostreptococcus anaerobius ATCC 27337.

Resting cells of Peptostreptococcus anaerobius maintained under anaerobic conditions were unable to metabolize either glucose or alanine. The addition of proline to the appropriate suspension, however, resulted in the immediate utilization of both compounds. Fermentation of alanine by the cells required that stoichiometric concentrations of proline be present in the medium; and during the oxidation of alanine, proline was simultaneously reduced to the ring cleavage product delta-aminovaleric acid.

Role of NADH oxidase in the oxidative inactivation of Streptococcus salivarius fructosyltransferase.

A cell-associated fructosyltransferase produced by Streptococcus salivarius was irreversibly inactivated in a time-dependent manner when resting or permeabilized cell suspensions were incubated with low concentrations (less than 1.0 microM) of copper. In addition to copper, the inactivation was dependent on oxygen and on a fermentable carbon source (endogenous intracellular polysaccharide or glucose).

Modifications of the involuntary postcontraction in diseased people.

The involuntary postcontraction (IPC) was studied on people affected by 12 different diseases or by noxious influences, and compared with that in healthy persons. General and disease-specific modifications are described and discussed. The suggestion is made that IPC could be used as a fast and easy test of the general state of health of the organism.

Does an increase in membrane unsaturated fatty acids account for Tween 80 stimulation of glucosyltransferase secretion by Streptococcus salivarius?

When Streptococcus salivarius was grown in batch culture in the presence of various Tween detergents, the fatty acid moiety of the detergent was incorporated into the lipids of its membrane. Tween 80 (containing primarily oleic acid) markedly stimulated the production of extracellular glucosyltransferase and also increased the degree of unsaturation of the membrane lipid fatty acids. The possibility that an increase in membrane unsaturated fatty acids promoted extracellular glucosyltransferase production was examined by growing cells at different temperatures in the presence or absence of Tween 80.

Effects of 6-hydroxydopamine on the carbohydrate metabolism of skeletal and heart muscles in rest and during exercise.

A mild 10 min exercise, induced by "in vivo" electrical stimulation of the rat gastrocnemius, causes decreases of the muscle glycogen content (G) and phosphorylase alpha activity (PA), and an increase of its overall glycolytic capacity (OGC); in the myocardium, PA decrease of liver glycogen were brought about by peripheral administration of 6-OHDA; these were probably also related to tissue hypoxia. Modifications elicited by exercise in 6-OHDA treated rats (increase of PA, but no modification of G and OGC in GM; decrease of G in the liver; decrease of OGC in M) suggest some impairments of the ability to adapt the tissue metabolism to increased energetic needs.

Inactivation of cell-associated fructosyltransferase in Streptococcus salivarius.

In stationary phase, 95% of the fructosyltransferase (FTase) activity of Streptococcus salivarius ATCC 25975 was found associated with the cells. Within the first 15 min after inoculation into fresh medium, the specific activity of cell-associated FTase decreased by 92% of its initial value. After this period of initial loss, the enzyme was synthesized during exponential growth until a maximum level equivalent to that present before inoculation was obtained.

Regulation and function of ammonia-assimilating enzymes in Streptococcus mutans.

The ability of Streptococcus mutans to synthesize amino acids was examined. A total of 8 of 12 laboratory strains grew anaerobically on solid-defined medium that contained no amino acids. Several isolates, therefore, assimilated ammonia for the biosynthesis of amino acids.

Regulation and function of sucrose 6-phosphate hydrolase in Streptococcus mutans.

Sucrose catabolism by Streptococcus mutans is initiated by a phosphoenolpyruvate-dependent sucrose phosphotransferase reaction that produces sucrose 6-phosphate the latter is then cleaved by a sucrose 6-phosphate hydrolase reaction that yields glucose 6-phosphate and fructose. We have examined the regulation of the sucrose 6-phosphate hydrolase and found that it was synthesized constitutively whereas sucrose phosphotransferase activity was inducible. However, the levels of both sucrose phosphotransferase and sucrose 6-phosphate hydrolase were repressed when fructose was used as a growth substrate.

Characterization of a phosphoenolpyruvate-dependent sucrose phosphotransferase system in Streptococcus mutans.

A phosphoenolpyruvate-dependent sucrose phosphotransferase system has been identified in Streptococcus mutans. Sucrose phosphotransferase activity was inducible by sucrose and had an apparent Km for sucrose of 70 microM. The product of the sucrose phosphotransferase reaction was isolated and identified as sucrose phosphate.