Strontium-90 was inject i.v. into pregnant rats on day 18 post conception (p.c.). This caused a remarkable transplacental radioactivity uptake and accumulation in the ossification centers of the skull basis. The total radiation dose within the surface of these regions was consequently calculated to be 0.6-1.2 Gy within the entire lifespan. About 50% of it was delivered during the 7 days following the injection of the isotope. The pathologic examination of the offspring throughout their lifetime revealed a pituitary tumor frequency in the exposed groups which was about tenfold in the males and threefold in the females in comparison to the controls. A very outstanding result in the animals treated was the occurrence of metastasizing meningeal sarcomas in about 6% of all cases. In four cases (= 2%) the simultaneous occurrence of a pituitary adenoma and of a meningeal sarcoma could be observed.

Because of the low safety factor estimated for the normal content of Cd in human foods, it is important to establish the influence of food constituents such as phytate on the bioavailability of this toxic metal. We studied the retention of radioactive(109)Cd administered to rats as a chloride or a phytate in a single dose by stomach tube. The animals were fed either a normal rat chow containing 0.29% of phytate or a low phytate diet containing less than 0.1% phytate. Highly elevated levels of(109)Cd were found only in the animals that were supplied with(109)Cd as a chloride and had been fed the low phytate diet. In the animals supplied with(109)Cd as a phytate, which had also received the low phytate diet, the levels of(109)Cd in the intestine were as high as those in the group mentioned before, but the retentions in all other tissues resembled those of the respective groups fed the normal chow. The findings indicate that phytate is responsible for a considerable decrease in the intestinal absorption of Cd. Furthermore, it appears to exert an influence on the kinetics of Cd retention in the intestine.

Zusammenfassung Beeinflussung der Cadmium‐Retention beim Hühnerküken durch Futterzusätze An Hühnerküken wurden verschiedene natürliche Futterkomponenten auf die Möglichkeit hin untersucht, die Cadmiumakkumulation in der Niere zu erniedrigen. Der Zusatz von Vitamin B6, Vitamin E, Mangan und Kupfer verringerte die Cadmiumbelastung der Niere nicht. Stattdessen stieg die Konzentration dieses Schwermetalls bei erhöhter Gabe von Kupfer dramatisch an. Zusatz von Fe2+ zur Diät ließ den Cadmiumgehalt geringfügig zurückgehen. Der deutlichste Schutzeffekt wurde jedoch mit Vitamin C und mit Selen erzielt. Da aber bereits bei geringen Selenüberdosierungen toxische Effekte auftreten, kann ihm keine praktische Bedeutung zukommen. Damit ist es das Vitamin C, das von allen in diesen und in früheren Studien untersuchten Diätfaktoren die stärkste Verringerung der Cadmiumbelastung herbeiführt. Unter Berücksichtigung dieser Befunde ist es möglich ungünstige Kükendiäten zusammenzustellen, bei denen die Cadmiumakkumulation in der Niere bzw. in der Leber trotz gleichem Cadmiumgehalt des Futters 16 bzw. 11 mal höher liegt als bei günstigen Diäten.

No abstract

The concentrations of nine inorganic elements were determined in dry samples of brain, liver, spleen, uterus, ovary and faeces of adult laboratory rats, using a method which combines chemical separation and determination by neutron activation analysis.Peculiar patterns of distribution were found for Na, Ca, Fe, Zn, Cu, MO, CO and Rb. Naximum concentrations of Zn, Cu, MO, CO and Rb were regularly found in liver tissue. W concentrations in the different tissues were not significantly different from one another and showed wide variations between samples of the same tissue derived from different animals. Our data compare well, both for animal and human material, with those available in the literature.