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Effect of single selank administration on activity of carboxypeptidase H and of phenylmethylsulfonylfluoride-inhibited carboxypeptidase - enzymes detaching arginine and lysine from C-terminus of molecules-precursors of biologically active peptides was studied. The preparation has been shown to cause long, preserved for 24 h changes of activities of these carboxypeptidases. It is suggested that the change in activity of the studied enzymes can be one of mechanisms of regulation of level of neuropeptides at action of selank.

Effects of a single administration of cholinergic drugs (arecoline, atropine, nicotine, mecamylamine) on the activity of carboxypeptidase H and of phenylmethylsulfonyl fluoride-inhibited carboxypeptidase, which are involved in metabolism of neuropeptides, were studied in brain parts and the adrenal glands of rats. The enzyme activities were determined fluorimetrically using specific inhibitors and substrates. In the majority of cases the enzyme activities decreased, and this decrease was retained for at least 72 h. Changes in the activities of the studied enzymes depended on the type of cholinergic action, the nervous system part, and the time after the injection. The changes in activities of the studied carboxypeptidases are supposed to be a possible mechanism responsible for changes in the levels of neuropeptides under the influence of high doses of the drugs.

The acid-base parameters and buffer systems of blood of different qualifying groups of sportsmen in physiological condition and at physical work were studied. It is shown that initial differences of the acid-basic condition and buffer capacity of integral blood of sportsmen of high qualifying group lead to changes of the pH dynamics at raising concentration of lactate. Dynamics of the blood lactate concentration is analyzed at stepped-raising exercise in sportsmen of different qualification, the possible molecular mechanism of sharp increase in concentration of lactate in the blood is discussed. It is shown that the point of a break on a curve of change of the pH precedes a point of break on a curve of increase in concentration of lactate at physical work. The received results can be used for definition of the moment of approach of an anaerobic threshold with pH-measurement of the blood.

The effect of a single dose administration of arecholine and atropine on the activities of carboxypeptidase H and phenylmethylsulfonyl fluoride-inhibited carboxypeptidase involved into the final stage of formation of biologically active neuropeptides from precursors has been studied. Changes in the enzyme activities were evident during at least 72 h after administration of these drugs. These results suggest that one of possible mechanisms of reduction of neuropeptide levels by arecholine and atropine consists in suppression of activity of enzymes taking part in there metabolism--carboxypeptidase H and phenylmethylsulfonyl fluoride-inhibited carboxypeptidase.

The activity of peptidyl-dipeptidase A and carboxypeptidase N taking part in peptide metabolism in the serum of patients with Alzheimer disease were studied. The role of these enzymes in the metabolism of neuropeptides and beta-amyloid at the Alzheimer disease was discussed.

The effect of a single atropine administration on the activities of angiotensin-converting enzyme and carboxypeptidase N taking part in peptides metabolism was studied. Changes in the enzymes activities after administration were evident during at least 72 h. The role of these enzymes in the metabolism of neuropeptides under the effect of atropine was discussed.