[Determination of procollagen type III aminopropeptide by a solid phase method using antibodies conjugated with peroxidase or protein A labelled with radioactive iodine]. / Opredelenie aminopropeptida prokollagena III tipa tverdofaznym metodom s ispol'zovaniem kon''iugata antitel s peroksidazoi ili belka A, mechennogo radioaktivnym iodom.

A solid-phase assay was developed for estimation of procollagen III aminopropeptide which involved both immunoenzymatic and radioimmune procedures. The assay did not require the iodine-labelled aminopropeptide, while content of the antigen was estimated using the conjugate of secondary antibodies and peroxidase or iodine-labelled protein A. Substitution of the protein A for the antibodies conjugate and peroxidase enabled to abolish the radioactive materials use.

[A fluorometric method of determining cholesterol esterase activity]. / Fluorometricheskii metod opredeleniia aktivnosti kholesterolesterzy.

A simple and highly specific method for estimating the cholesterol esterase activity is suggested. Cholesterol esterase (EC 3.1.1.13) is incubated with the emulsified substrate, cholesteryl-o-coumarate, at pH 6.6 to yield o-coumaric (trans-2-hydroxycinnamic) acid detected fluorimetrically (lambda exc 363 nm, lambda em 494 nm) at pH 10.4. The fluorescence associated with the unhydrolyzed substrate is negligible. Cholesteryl-o-coumarate is not hydrolyzed by pancreatic lipase, trypsin, or chymotrypsin under the above conditions. About 1 microgram of pancreatic cholesterol esterase can be determined upon 15 min incubation. The substrate was synthesized by condensation of o-acetoxy-trans-cinnamic acid with cholesterol using the di-tert-butyl pyrocarbonate--pyridine--4-dimethylaminopyridine system.

[Assessment of cholesterol esterase activity in the duodenal contents of man]. / Opredelenie aktivnosti kholesterolésterazy v duodenal'nom soderzhimom cheloveka.

In 20 healthy patients the cholesterol esterase activity in duodenal content was examined. The cholesterol ether of o-coumaric acid was used as a substrate. Increase of the cholesterol esterase activity was noted after stimulation of pancreozymin and secretin. The cholesterol esterase concentration in duodenal content changes in more wide range than the index of the output. The cholesterol esterase output is the most significant informative index. There is not any cholesterol esterase activity in bile, gastric juice and saliva. The results obtained have shown that the main part of the estimated cholesterol esterase activity has a pancreatic base. The investigation of the cholesterol esterase activity in duodenal content may be used in the study of the exocrine function of pancreas.