In the study with experimental animals in vitro conditions, the aim of the research was to examine the effect of verapamil on the even brawniness of the isolated organ of the respiratory ways (tracheas) in guinea-pigs on acetylcholine and histamine, and in that way, to examine local mechanisms of smooth muscle system but also to exclude the rest of the neurohumoral influences. The guinea-pigs of both sexes (average weight of 500-700 gr), were used for this experiment. 10 guinea-pigs were included in the experimental research; the trachea was taken from them after the immolation. The preparations of isolated organs of trachea were divided into two groups (A and B). The previous incubation of trachea -5 isolated by verapamil (1 minute) in concentration 10 M significantly reduced the contraction caused by acetylcholine -4 (ascent 21.49±9.63, r=0.97, p<0.05). Concentration of verapamil 10 M also caused significant fall of contraction (ascent -5 21.3±12.63, r=0.95, p<0.05). Verapamil in concentration 10 M significantly reduces the response of isolated trachea cau- -6 -5 -4 sed by histamine in concentrations 10 M and 10 M (slope 21.3±10.6, r=0.96, p<0.05).Concentration of verapamil 10 M significantly reduced the contraction of smooth muscles of isolated trachea caused by histamine (slope 15.46±10.47, r= 0.94, p < 0.05).

Conducting research in the field of respiratory function, by using measuring and testing, has many purposes. First of all, it could show us how lungs function as a whole, but also, it could lead us to the exact location of a disorder. The aim of this paper is to, by employing accurate correlation of the measured variables of the flow/volume and flow/pressure curves, determine the location of the obstruction process in the tracheobronchial tree, in central-upper airways, as well as in a segment of small airways, so called 'silent zones' of the lungs, smaller than 2 mm in internal diameter. This research included 115 healthy people and 106 patients with chronic obstructive lungs disease, of both genders. The following values of the measured lungs' function parameters were found among healthy people (% of predicted value): FVC- 93%; FEV - 91,1 %; 1 FEV x 100/ FVC- 98,7%; MEF - 107,9%; MEF - 87,5%; MEF-98,9%; Rt-147,1%; ITGV-103,3%; SRt- 130,7%. 1 25%FVC 50%FVC Among the patients with chronic obstructive bronchitis, the following results of the examined parameters were gained: FVC- 66,3%; FEV - 54,2%; FEV x 100/ FVC- 80,7%; MEF - 19,3%; MEF - 23,1%; MEF- 40,5%; Rt- 51,2%; 1 1 25%FVC 50%FVC ITGV- 162,1%; SRt- 36,2%. Finally, there was a certain number of the healthy examinees who showed that direct indicators of the air flow resistance (Rt, SRt) were not significantly changed, while indirect indicators of the respiratory tracts obstruction (MEF , MEF ) were reduced, comparing to the expected tabular results.

Many researchers and clinical doctors have realized that spirometric tests, as well as the resistance of airways, could be within the normal limits at people who have clear signs of bronchitis (coughing, expectoration and lighter disphnoe). Very often, especially among smokers, they have found discrepancy between the functional tests' results and clinical symptoms, although they could expect to find minor lungs' diseases within this group of people. Obstructive lesions in small airways are very often present at smokers older than 40 years, whose lungs are macroscopically normal, and who do not show clinical signs of the obstructive lung disease ('asymptomatic smokers'). The aim of the paper was to find which test, among the most often-used tests for the functional research of the respiratory system, represented the best indicator of the initial obstructive changes localized in small airways. The research study included 50 asymptomatic smokers (34 male and 16 female) ranging from 44 to 57 years. The results of the achieved FVC were at normal level, at all examinees. Out of 50 examinees, asymptomatic smokers, there was one examinee (2%) with the lower level of FEV , while at two examinees 1 (4%) lower levels of SRt and MEF were found. Significantly lower levels of the measured MEF were found among 50%FVC 25%FVC 16 asymptomatic smokers (32%). Such a functional result, i.e. a decrease of MEF while the levels of FVC, FEV , Rt, 25%FVC 1 SRt and MEF are normal, accompanied by a long-lasting smoking case-history with less expressed symptoms, points at 50%FVC the existence of the obstructive disorders localized in the periphery parts of the bronchial tree (small airways). The registration of the flow/volume curve and its analysis might be used as a test even more sensitive than spirometry and body pletizmografy; as a test it can be used for a diagnosis of initial obstructive difficulties in small airways, in other words, it could diagnose the small airways disease.