Indicators of proteinase inhibitory system in the bronchi of guinea pigs in the late period of experimental asthma

Abstract

Aim. Study the state of proteinase inhibitory system in the bronchi of guinea pigs in the late period of formation of experimental bronchial asthma (BA). Materials and Methods. Experimental studies were conducted on guinea pigs, divided into five groups: I - control group; group II - guinea pigs at day 5 of experiment; group III - guinea pigs at day 19 of bronchial asthma development; group IV -day 26 of experiment; and group V - day 33 of asthma process. Early period included groups of animals on the day 5 and day 19 of experiment. The late period included guinea pigs on day 26 and day 33 of bronchial asthma. Experimental bronchial asthma was simulated by the method of V.I. Babych (1979). Condition of proteinase inhibitory system in the bronchi was determined by lysis of the azoalbumin, azocasein and azocollagen and maintenance content of a1-protease inhibitor (a1-PI), a2-macroglobulin by method of K.N.Veremeenko and O.P. Goloborodko (1988). Results and Discussion. Results of biochemical studies suggest that the animals with induced experimental asthma symptoms show features of imbalances of the proteinase inhibitory system. Thus, on the 26th day of this pathology an increased content of azoalbumin by 69,7% (p<0,05) compared with the control group of animals was revealed. Later, on the 33rd day of asthma an even more significant increase in its levels in the bronchi to 107,2% (p<0,05) compared with I group was revealed. The level of another indicator - azocasein in the bronchi raises in groups IV and V in this experiment, respectively, by 98,5% (p<0,05) and by 133,8% (p<0,05) compared with the control group. An important marker that complements the other characteristics is azocollagen. The late period of astma formation was accompanied by its growth compared to the intact group by 107,7% (p<0,05) after 26 days of the experiment, and this figure remained higher by 138,5% (p<0,05) compared to the control group of animals on the 33rd day of asthma, which points to acceleration of the proteolysis processes. Determination of a2-macroglobulin activity in the bronchi in the late period of asthma formation showed its gradual decrease by 45,1% (p<0,05) on day 26 and by 64,6% (p<0,05) on day 33 of the experiment compared with the first group of guinea pigs. The study of the a1-PI made it possible to identify a similar trend of the changes. Thus, on day 26 and day 33 of the experimental course of the disease a reduction of its activity compared to the control groupby 55,5% (p<0,05) and by 75,5% (p<0,05), respectively, was determined. Conclusions. Determining the individual components of the proteinase inhibitory system in the bronchi in the course of BA development revealed excessive formation of products of proteolysis against a background of exhaustion of compensatory mechanisms of the inhibitory system, especially in the later period, namely, on day 33 of the experimental asthma, indicating substantial disturbance of the functional state of the proteinase inhibitory system.

Keywords

• asthma, azoalbumin, azocasein, azocollagen, a1-protease inhibitor, a2-macroglobulin