Biomedical subjects

S Reuber

Publications and source records attributed to S Reuber.

3 recordsLinked to original sources

PubMed1994

Interactions of cobalt and iron in absorption and retention.

The effects of supplementary oral cobalt and iron, as well as the interaction between both at the absorption site, fecal and urinary excretion as well as the retention of these trace elements were determined by using four diets containing either 9 or 63 micrograms/kg of Co and 48 or 446 mg/kg of Fe over a period of 19 days in a total of 24 rats. Retention was calculated by the balance technique and by the comparative slaughter technique. After one day, fecal as well as urinary excretion of both elements had already responded to the dietary treatments, with constant values being reached after approximately three days. Cobalt excretion was enhanced by supplementary cobalt; fecal excretion, too, was increased by supplementary iron; whereas urinary excretion was decreased in both cases. Additional iron significantly inhibited the absorption of cobalt in both dietary cobalt treatments. The lower rate of absorption in the groups receiving 446 mg Fe instead of 48 mg of Fe per kg diet resulted in a decreased renal excretion of cobalt. Consequently, the effect of iron on the retention of cobalt was lower than on absorption. This suggests that interactions between the two elements only take place at the site of absorption. Because of the low dietary cobalt concentration as compared to the iron contents of the diets, no effect of cobalt on iron absorption and excretion occurred. Differences in iron balance were only observed between both dietary concentrations, showing a higher absolute but a lower relative absorption as well as retention in the groups fed further Fe.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1994

[Increasing physical endurance with salmeterol].

10 patients with mild to moderate chronic obstructive pulmonary disease were assessed by lung function tests at rest and spiroergometry before and 1 resp. 7 hours after inhalation of 50 micrograms salmeterol. The parameters changed as follows: Forced exspiratory volume in 1 second: +16% +/- 6% after 1 resp. +13% +/- 5% after 7 hours; airway resistance: -43% +/- 11% resp. -43 +/- 9%. Work capacity at the anaerobic threshold (AT): +44% +/- 17% resp. +37% +/- 16%, oxygen consumption at the AT (VO2AT): +53% +/- 18% resp. +54 +/- 23%, ventilation at the AT (VEAT): +31% +/- 11% resp. 30% +/- 7%. Maximum work capacity: +14 +/- 5% resp. +22 +/- 7%, maximum oxygen consumption (VO2max) +58 +/- 24% resp. 64 +/- 22%, maximum ventilation (VEmax) +33 +/- 10% resp. + 46 +/- 11%. In conclusion, salmeterol leads to a long lasting improvement of exercise capacity. This is related to the improvement of the ventilation caused by salmeterol. Significant changes of heart rate or blood pressure were not observed.

Administration, Inhalation↗

PubMedDate not supplied

Endogenous excretion and true absorption of cobalt as affected by the oral supply of cobalt.

At the end of a 49-d experiment with 32 growing male rats, a period of 8 d was used to determine endogenous excretion and true absorption as well as apparent absorption and retention of cobalt with the aid of the isotope dilution technique. For this purpose, a single im dose of 58Co was applied at d 35 of the experiment. After that, urine and feces were collected separately from d 8 to 15 after injection of the isotope. The specific cobalt activity of the liver was used as an endogenous reference source. The basal diet provided 5.9 ppb cobalt, the different treatment groups were obtained by supplementing the diet with 0, 10, 50, 250, or 1250 ppb cobalt. The different diets were offered from the beginning of the experiment. In the balance period, apparent and true absorption as well as fecal excretion behaved similar to cobalt intake, whereas urinary excretion increased more rapidly with increasing cobalt supply. Endogenous fecal excretion accounted for 3.5 ng Co/d in the groups fed the diets without and with 10 ppb cobalt. An increase was not observed until supplementing the diet with 50 ppb cobalt. This increase between 250 and 1250 ppb cobalt was higher than the corresponding increase in the dietary cobalt supply. This indicates that endogenous fecal excretion might be more important for homeostatic regulation at a higher dietary cobalt concentration. Endogenous renal excretion as calculated from the results of the isotope dilution technique showed a similar kind of response to increasing cobalt supply as endogenous fecal loss. Nevertheless, the elimination of excessive cobalt mainly took place by adjusting urinary excretion, whereas the variations in true absorption and endogenous fecal excretion had no quantitative importance. Apparent and true absorption were on average 28.0 and 29.8%, respectively, of the cobalt intake. In the case of retention, a marked decline was observed from 19% in the depletion group to 3% with 1250 ppb cobalt, again demonstrating the importance of urinary excretion for controlling the cobalt content of the organism.

Administration, Oral↗