[Inhibition of cholinesterases of varying origin by ordinary and betaine vinylphosphates]. / Ugnetenie kholinésteraz razlichnogo proiskhozhdeniia obychnymi i betainovymi vinilfosfatami.

The comparative study of irreversible inhibitory action of some substituted vinyl-phosphates (in usual and betaine forms on cholinesterases from different biological sources such as the human blood erythrocytes, the horse and the hen blood serum and optic ganglia of the squid) has been carried out. It is shown that betaines obtain lesser inhibitory activity as compared with the corresponding ordinary vinylphosphates. Some of tested inhibitors display expressed selectivity of action. So, the compound GL-2 reacts with cholinesterase of optic ganglia of the squid 450 000 times faster than with cholinesterase of the hen blood serum. The application of vinylphosphates as inhibitors of cholinesterases allows displaying additional differences in properties of enzymes. It is very important for comparative enzymology. These compounds may be used for detalization of type belonging and to make the classification of cholinesterases more accurate. Moreover, the estimation of anticholinesterase activity of vinylphosphates is important because these compounds may be used both in medicine and agriculture.

[The reversible inhibition of cholinesterases from different biological sources by phosphonium betaines]. / Obratimoe ugnetenie kholinésteraz iz rachlichnykh biologicheskikh istochnikov fosfonievymi betainami.

The action of some phosphonium betains on cholinesterases from different biological sources has been studied. It has been shown, that all studied betains are reversible inhibitors of cholinesterase hydrolysis of acetyltiocholine. Inhibiting action of these compounds on acetylcholinesterases is about ten times weaker that of the majority of known phosphonium salts, while their action on butyrylcholinesterases has no peculiarities. There were found certain differences for each betain compounds in their action on cholinesterases from different biological sources. These results may be used for detail classification of cholinesterases and allow to extend knowledge in comparative enzymology.

[A kinetic study of the blood serum cholinesterase activity in the freshwater fish Abramis ballerus]. / Kineticheskoe issledovanie kholinésteraznoi aktivnosti syvorotki krovi presnovodnoi ryby Abramis ballerus.

In reaction of hydrolysis of choline and thiocholine esters of carbonic acids at 25 degrees C, cholinesterase activity of the blood serum from the fish A. ballerus has been studied by modified Ellman's method and potentiometric titration method. The activity is maximal in pH region 7.5-9.0 and is not inhibited by high concentration of substrates. Michaelis constants and maximal rates for the enzyme reactions were determined. Butyrylcholine and butyrylthiocholine were hydrolyzed with the highest rates by the serum. Some of the organophosphorus inhibitors (diisopropylfluorphosphate and DDVF) inhibit cholinesterase activity of the blood serum significantly faster, whereas some of the carbamates (aminostygmin, eserine, etc.) inhibit it significantly slower than typical butyrylcholinesterase from horse blood serum and typical acetylcholinesterase of human erythrocytes. Besides, with respect to the sensitivity to inhibitors and some other properties, fish blood serum cholinesterase differs from other known cholinesterases.

[Reversible inhibition of cholinesterases by salts of pyrilium, thiopyrilium and selenopyrilium derivatives]. / Obratimoe ingibirovanie kholinésteraz soliami proizvodnykh piriliia, tiopiriliia i selenopiriliia.

Salts of pyrilium, thiopyrilium and selenopyrilium derivatives at pH 7.5 and temperature of 25 degrees C are studied for their effect on the catalytic activity of acetyl cholinesterase (EC 3.1.1.7) of human blood erythrocytes and butyryl cholinesterase (EC 3.1.1.8) of horse blood serum which is measured by the method of potentiometric titration. All enumerated salts are established to be strong reversible inhibitors of mixed-type cholinesterases, that is testified by small values of the inhibitory constants: competitive Ki, noncompetitive K'i and generalized K epsilon. Pyrilium and selenopyrilium salts inhibit acetyl cholinesterase of human blood erythrocytes to a higher extent than butyryl cholinesterase of horse blood serum, and thiopyrilium salts inhibit the latter to the highest extent. By the value of the inhibitory effect on acetyl cholinesterase of human blood erythrocytes thiopyrilium salts exceed the analogous pyrilium salts, whereas in experiments with butyl cholinesterase of horse blood serum there is an opposite dependence.

[Kinetics of reversible inhibition of cholinesterases by quaternary diaminoalkyl esters of aromatic dicarboxylic acids]. / Kinetika obratimova ingibirovaniia kholinésteraz chetvertichnymi diaminoalkilovymi éfirami aromaticheskikh dikarbonovykh kislot

Reversible inhibition of acetylcholinesterase (AChE) from bovine erythrocytes and butyrylcholinesterase (BuChE) from horse blood serum by quaternary diaminoalkyl esters of suberic (D-6), p-phenylenediacetic (PK-139), p-phenylenedipropionic (PK-154 and PK-155), p-phenylenediacrylic (PK-150 and PK-151) and phthalic (PK-105) acids, was studied under the following incubation conditions: pH 7.5, 25 degrees C, 0.1 M KCl. The inhibition kinetics were of a mixed competitive-incompetitive type, the incompetitive component alpha'-having higher values for AChE (0.26-0.60) than for BuChE (0.10-0.20). Diester PK-150 selectively inhibited BuChE (Ki=3.0-10(-6) M); its Ki value for AChE was 4.0-10(-4) M. The other diesters had a stronger inhibitory effect on AChE than on BuChE. High values of alpha' observed during AChE inhibition cannot be interpreted in terms of interaction of those bisquaternary compounds with the anionic site of the acetylated active centre and are probably due to their sorbtion at the peripheral anionic sites. Incompetitive inhibition constants (K'i=Ki/alpha') of BuChE by the diesters PK-139, PK-154 and PK-150 were found to be values of the same order as substrate inhibition constants determined in the course of BuChE hydrolysis of these diesters. Incompetitive inhibition found for the esters studied and substrate inhibition during hydrolysis of these compounds are presumably due to the same mechanism.

[Kinetics of enzymatic hydrolysis of quaternary aminoalkyl esters of aromatic mono- and dicarboxylic acids by butyrylcholinesterase from horse serum]. / Kinetika fermentativnogo gidroliza chetvertichnykh aminoalkilovykh éfirov aromaticheskikh mono- i dikarbonovykh kislot butirilkholinesterazoi iz syvorotki krovi loshadi

Enzymatic hydrolysis kinetics of benzoylcholine (BzCh), phehylpropionic acid choline ester (PK-157), suberic acid dicholine ester (D-6) and p-phenylenediacetic (PK-139), p-phenylenedipropionic (PK-154 and PK-155), p-phenylenediacryc (PK-150 and PK-151) and phtalic (PK-105) acids diaminoalkyl esters by horse blood serum butyrylcholinesterase (BuChE) was studied. Hydrolysis constants Km, V and Kss were estimated by means of different graphic methods. PK-157 ester turned to be highly specific selective substrate for BuChE, its V being 20 times as high and Km -- 20 times as low as those for acetylcholine (ACh). The highest V value was found for D-6 in the case of diesters. Hydrolysis of aromatic dicarbonic acids diesters was characterized with significantly lower V values (0.6-10.% of V for ACh) and extremely low Km values (approximately 10(-5) -- 10(-6) M). Substrate inhibition was observed under the hydrolysis of BzCh, PK-157, D-6 and all aromatic dicarbonic acids esters by BuChE. Formal kinetic analysis revealed that inactive complex, which formed in this case, corresponded to ES2 composition. The appearance of substrate inhibition for BuChE and its increasing are supposed to be due to the increase in the size and in the rigidity of the acyl part of the molecule in the number of substrates studied.

[Quantitative and qualitative changes in the sex chromatin of diabetic women of different ages]. / Kolichestvennye i kachestvennye izmeneniia polovogo khromatina u bol'nykh sakharnym diabetom zhenshchin raznogo vozrasta

There was revealed a statistically significant reduction in the frequency of occurrence of sex chromatine (SC) in the patients (female) suffering from diabetes mellitus aged from 15 to 65 years before the treatment in comparison with the healthy women. After the compensation of the carbohydrate metabolism there was noted its further reduction in the patients aged from 25 to 65 years. In 15-65-year women who contracted diabetes mellitus there was an increase in the circular form of the SC bodies looking like thickenings of the nuclear membrane; SC bodies of round shape enlarged as well in women aged from 25 to 65 years. Oval, triangular and semicircular forms decreased in all the age groups. After the compensation of the carbohydrate metabolism the content of the SC bodies of various shapes remained the same as at the beginning of the disease without returning to the normal level. The area of the SC bodies enlargement was statistically significant in women who fell ill with diabetes mellitus.