[Analysis of peptides from animal and plant tissues].

A new technique was developed for the analysis of peptide compositions of extracts from various animal and plant tissues. It involves the acidic extraction of a peptide fraction from the starting material and its precipitation with acetone, fractionation of peptides by ion-exchange chromatography by using a stepwise elution of fractions and detection by means of ninhydrin color reaction, and computer processing of the results. For the presentation of the results of analysis, chromatographic profiles and peptidograms were proposed.

[The toxicity of different forms of 24,25-dihydroxycholecalciferol preparations in rats].

The purpose of the study was to examine the toxicity of 24,25-DOXK on calcium-phosphorus metabolic parameters. The rats from experimental groups received enteral 50- and 1,000-fold physiological doses of 24,25-DOXK (Vitamins Research Production Association) as a combination of R- and S-epimers and homogeneous R-epimer in sunflower oil solutions or ethanol mixture (1:4 propylene glycol) during 3 and 7 days. Though there was a stable tendency for hyperphosphatemia and altered blood calcium concentrations, the 24,25-DOHK formulations under test, unlike 1-OXK and 1,25-DOXK, displayed no toxic properties on the kidney, heart and aorta and produced a mineralizing effect on bone tissue in the acute period.

[Assessment of the activity of choline acetyltransferase in heart tissues].

A procedure is described for the radioisotope assay of acetylcholine transferase activity (EC 2.3.1.