Thanks to present-day achievements of enzymology, proteolytic enzymes have become common use in medicine. Proteases play an extraordinary role in protein metabolism, klendusity (blood coagulation, clot lysis), immune responses, morphogenesis, cell-cell interactions, oncogenic transformation, virus pathogenicity, etc.
The purpose of the present work has become the study of the circadian dynamics of some physiological parameters of blood.
White both sex non-pedigree rats weighing 200-270 g were used as the research objects. Every hour blood samplings were taken during the day using the decapitation method. In all the blood samples the level of general proteolytic activity of blood (GPA), total protein concentration, the amount of erythrocytes, leucocytes, hemoglobine were determined, the plasma pH was measured. The accumulation of free amino acids and peptides having NH2-groups in the probes incubated within 4 hours at 37◦С was considered to be the GPA level index. The findings were stated in mcg of glycin per 1 ml of plasma (or erythrocytes) for an hour of the incubation. The erythrocytometry was carried out using the method of microscopy with the help of the program "Videotest" (to study blood formed elements).
The carried out research have detected the presence of distinct interrelation between the proteolysis processes and time of the day. It has been determined that plasma proteinases, like erythrocyte proteinases, manifest their maximal activity at night (from 24.oo till 05.00 in the mean). The determination of plasma total protein amount has detected the presence of two peaks of activity of the given parameter in all the probes during the day: 1st peak - from 10.00 till 14.00, 2nd peak - from 19.00 till 24.00.
A large body of circadian activity research of blood composition factors in intact rats (576 species) showed that there are no considerable fluctuations of hemoglobin, erythrocytes and leucocytes amount, and also plasma pH, during the day that testifies to the lack of distinct diurnal rhythms, which occurred while investigating blood proteolytic activity.
The article is admitted to the International Scientific Conference «Basic and applied research in medicine», Thailand (Bangkok, Pattaya), December 19-27, 2007, came to the editorial office on 06.11.07