Polaprezinc, an insoluble zinc complex of L-carnosine, exhibits anti-ulcer effects by acting directly on mucosal lesions. The disposition of polaprezinc in the stomach was studied to clarify the usefulness of its structure as an insoluble complex. The time courses of 14C-radioactivity in the gastric contents and gastric tissues were parallel to those of 65Zn after oral administration of a mixtu...

1. A technique is described for the measurement of the extent of 65Zn absorption by different regions of the intestine in the intact rat. Using this technique it was shown that the duodenum contributed 60%, the ileum 30% and the jejunum 10% to the over-all absorption of 65Zn. Negligible absorption of 65Zn occurred from the caecum and colon. 2. Using ligated loops of rat duodenum in situ, 65Zn a...

Brush-border-membrane vesicles were prepared from piglet small intestines and the uptake of 65Zn was studied using a rapid filtration assay. The mechanism of 65Zn uptake was complex and two processes were identified. In the first process, 65Zn uptake was rapid, reached equilibrium in 5-15 min and had an optimum pH of 7.5. The uptake was saturable and involved both binding to, and transport acro...

Zinc, an essential trace element, is present in unusually high concentrations in the chorioretinal complex relative to most other tissues. Because little has been known about the interactions between the retinal pigment epithelium and free or protein-associated zinc, we studied 65Zn uptake by human retinal pigment epithelium in vitro. When monolayers were exposed to differing concentrations fro...

65Zn is one of the induced radioactive nuclides which are generated in power reactors. In the present experiment, several parameters of 65Zn metabolism were studied in mice maintained on diets with various zinc contents from 45 to 4,500 mg/kg to evaluate the efficacy of the dilution method for radiation protection against internal contamination with 65Zn. Gastrointestinal absorption of 65Zn was...

This study was designed to determine the effect of nickel treatment on biological half-lives of 65Zn in whole body and liver as well as on distribution of 65Zn in different organs of protein deficient rats. Nickel sulfate at a dose level of 800mg/l in drinking water was administrated to normal control as well as to protein deficient rats for 8 weeks. A significant increase was found in fast and...

Previous autoradiographical studies utilizing 65Zn demonstrated an apparent concentration of 65Zn in the mossy fiber boutons of the hippocampus. To examine the speciation of the 65Zn pool found in this neuronal pathway, we investigated the in vivo incorporation of systemic 65Zn into rat hippocampus compared with other brain regions. We were especially interested in kinetically assessing the zin...

Cells from a human prostatic adenocarcinoma cell line (PC3) were maintained in M199 medium, with and without 5% Bobby calf serum, to examine aspects of cellular zinc metab olism. Cultures contained 0.5 to 1.0 x 106 cells/dish. En hanced 65Zn accumulation in response to dexamethasone was observed after 24 hr in culture. The rate of efflux of accumu lated 65Zn was not influenced by this hormone. ...

1. Male Wistar rats (approximately 200 g) were given distilled water and a semi-synthetic control diet for 6 d. On day 7, 37 kBq 65Zn were administered intramuscularly and the rats were given distilled water, beer, cider, red wine, whisky or ethanol as their only source of fluid. The wine, whisky and ethanol were diluted so that each of the beverages contained a similar ethanol concentration (a...

Tetanus toxin was shown to contain a metal-binding site for zinc and copper. Equilibrium dialysis binding experiments using 65Zn indicated an association constant of 9-15 microM, with one zinc-binding site/toxin molecule. The zinc-binding site was localized to the toxin light chain as determined by binding of 65Zn to the light chain but not to the heavy chain after separation by sodium dodecyl ...