Accumulation and metabolism of uneven fatty acids present in single cell protein

Liquipron and Toprina, obtained by growing yeasts (Candida maltosa and Candida lipolytica) on n-hydrocarbons, were investigated to ascertain the biological significance and possible toxicological implications of their high content of uneven fatty acids (UFA). It was confirmed that the extent to which UFA accumulate in adipose tissue of rats fed the 2 products reflects only partially their UFA contents. The presence of UFA in rat tissues does not appear to alter intermediate metabolism. The capacity of liver mitochondria ot oxidize palmitic acid was similar in control and in Liquipron-treated rats. Palmitic acid and heptadecanoic acid did not compete for oxidation when mixed at concentrations which reflect their presence in the tissues of animals fed high levels of Liquipron.     

The age-related decline in intestinal lipid uptake is associated with a reduced abundance of fatty acid-binding protein

Aging is associated with changes in the absorptive capacity of the small intestine. We tested the hypotheses that (i) aging is associated with a decline in lipid absorption, and that (ii) this decreased lipid absorption is due to a decline in the abundance of mRNA and/or the enterocyte cytosolic intestinal FA-binding protein (I-FABP), the liver FA-binding protein (L-FABP), and the ileal lipid-binding protein (ILBP). In vitro uptake studies were performed on Fischer 344 rats at ages 1, 9, and 24 mon. Northern blotting (L-FABP, ILBP) and immunohistochemistry (I-FABP, ILBP) were performed. Aging was associated with decreased animal weights, but the surface area of the intestine was not significantly altered with age. The rates of ileal uptake of 16∶0, 18∶0, 18∶1, and 18∶2 were reduced by greater than 50% with aging when expressed on the basis of mucosal weight. This decline was not associated with reduced expression of mRNA for L-FABP or ILBP but was associated with a 50% decrease in the abundance of I-FABP and a 40% decrease in the abundance of ILBP. Thus, the decrease with aging in the ileal uptake of some FA when rates were expressed on the basis of mucosal weight was associated with a reduced abundance of I-FABP and ILBP.     

Procedure for analysis of radium in freshwaters by adsorption on basic lead rhodizonate

Radium analysis is carried out by batch adsorption from natural waters on basic lead rhodizonate supported on charcoal, LERHO, starting from 2-L samples. 133Ba is added to allow the measurement of the overall chemical yield by gamma counting. Radium is recovered with a few milliliters of 1.5 M HCl, and lead is removed by a chromatographic column filled with Dowex 2 x 8. Finally 50 micrograms of barium carrier is added, and the radium is coprecipitated as sulfate on a preformed bed of barium sulfate, to prepare a sample suitable for alpha and gamma counting. The detection limit of the proposed method is 0.002 Bq/L 226Ra. This value is far beyond the radium activity admissible for drinking waters. Due to lack of appropriate samples, the procedure was tested using mineral waters spiked with 226Ra and two commercially available mineral waters with very low radium contents.