[Intestinal absorption of vitamin B6 in vitro in response to the mucosal concentration of pyridoxine . HCl (author's transl)].

The in vitro absorption of vitamin B6 from the mucosal to the serosal solution was studied, using everted sacs of the proximal jejunum of male rats. The concentration and the absorbed amount of vitamin B6 in the intestinal wall and in the serosal solution was measured after an incubation of 45 minutes with 0, 2, 4, 10, 25, 50, 100, 200, 500 micrograms pyridoxine . HCl (PN .

[Pregnancy anabolism of the trace elements copper, zinc, nickel and manganese in sows].

In an experiment with 16 sows of the German Landrace the influence of gravidity and a varying dietary trace element supply on the total balance of copper, zinc, nickel and manganese was tested from the 21st day of gravidity until farrowing. The trial was of a factorial design (2X2X3). The balances were measured with 8 nongravid and 8 gravid sows at two levels of trace element supply (basic and supplemented groups) in three collecting periods.

[Intestinal absorption of zinc during gravidity and lactation (author's transl)].

In two experimental series the absorption of zinc was continuously studied during gravidity and lactation with Sprague-Dawley rats of the same age. The absorption was measured in vitro with isolated, everted intestinal sacs. During the first third of gravidity the absorption of zinc--based on the intestinal Zn transfer to the serosal solution and the Zn uptake into the intestinal wall--rose at first slightly, during the second third it continued to increase, whereas there was a highly significant increase during the last third of gravidity in comparison to nongravid, nonlactating control animals (P less than 0.

[Effect of inhibition of intestinal glucosidase on protein and energy balance in rats].

In a two-factorial balance trial two dietary protein levels of 12 and 15% the effect of a supplement of 50 mg alpha-glucosidase inhibitor (Bay g 5421) per kilogram food on nutrient digestibility, protein, and energy balance was tested in growing rats. At both protein levels the alpha-glucosidase inhibitor reduced the apparent digestibility of protein by maximal 8 and 4%, those of starch and energy only by 3 and 1%, respectively. With the low protein supply the protein and energy retention was decreased each by 13% when the inhibitor was given.

[Nutritive effects of an intestinal alpha-glucosidases-inhibition in rats (author's transl)].

In a balance trial the effect of different dietary doses of the alpha-glucosidases-inhibitor Bay g5421 on nutrient digestibility and N-balance was tested with rats. The supplements of 30, 90 and 210 mg Bay g5421 per kg of feed reduced the digestibility of starch plus sucrose by 2, 16 and 27%. The protein digestibility decreased by 5, 14 and 19%.

[Alpha amylase and dehydrogenase activity in suboptimal Ni intake].

Supplementary to studies on the activity of various enzymes during Ni deficiency, the present work was done to determine their response to suboptimal Ni supply. Live weight gain of rats was not affected by 60 versus 150 ppb Ni in the diet. The activity of alpha-amylase, however, was reduced by 43% in the case of 60 ppb dietary Ni and in relation to the change in this enzyme the activity of glucose-6-phosphate dehydrogenase by 56% and of the lactate dehydrogenase by 27%.

Trypsin activity in the small intestine of rats after application of copper and zinc.

In vivo experiments with Sprague-Dawley rats were conducted in order to explore the influence of Cu(2+), Zn(2+) as well as of the combinations of both on the activity of trypsin. The solutions of the trace elements were given per os, the animals were killed 30 min after the applications, and the activity of trypsin was determined in the juice of the small intestine by usingN (α)-benzoyl-L-arginine-p-nitroanilide (L-BAPA) as the substrate. The activity of trypsin depends on the concentration of the trace elements.

[Deficient nickel supply and the content of calcium, magnesium and phosphorus inthe bone of growing rats].

Based upon studies on Ni deficiency with marked changes in intermediary metabolism, the recent investigation examined the extent to which deficient Ni supply affects the content of calcium, magnesium and phosphorus in rat femurs. In Ni deficiency the content of calcium and phosphorus was reduced, in the case of calcium even more so than accounted for by the decrease in bone weight. The result was Ca : P ratio of 1.

[The influence of ceruloplasmin injections on the Cu- and Fe-metabolism of piglets].

In two experiments with a total of 56 piglets the influence of intravenous injections of ceruloplasmin (CP) on the 2nd and 4th day of their lives on criteria of the Cu- and Fe-metabolism was investigated. Due to the injections, the CP-activities and the Cu-concentration in the plasma increased, as a rule, more than in the untreated control animals. This effect was more distinct and longer recognisable after the injections on the 2nd day of life.

[Effects of iron supply and lactation on iron availability in intermediate metabolism].

The availability of iron in metabolism was determined in dependence on the performance after lactation had finished and on the level of Fe-supply of a total of 56 rats. The availability of iron of those animals which had reared young was, according to the increased requirement, high and decreased from 87 to 54% after increased doses of iron. The values of full-grown control animals were considerably lower and had a falling tendency from 52 to 36% after an increasing supply with iron.

Total true efficiency of zinc utilization: determination and homeostatic dependence upon the zinc supply status in young rats.

Total true efficiency of zinc utilization and its component factors, true absorption and metabolic efficiency, were studied in relation to dietary zinc supply in a 15-day experiment with 36 weanling rats in six groups. After day 3, the initial supply of 18.2 ppm zinc in the diet for all groups was changed to 5.