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13BIOLOGICAL SCIENCES
REACTIVITY OF STUDENTS' TISSUE BLOOD FLOW DURING THE TEST WITH BATED
BREATH
Horban D.
Department of Anatomy and Physiology of People and Animal Bogdan Khmelnitsky Melitopol State Pedagogical University Hetmanska St, 20, Melitopol, Ukraine, 72300
Abstract
The purpose of the research is to reveal the individual-typological peculiarities of the reactivity of student's capillary blood flow and to trace the change of the indicators of the blood microcirculation during the test with the bated breath. The experimental research has included the study of the functional state of the tissue blood flow by means of laser Doppler flowmetry (LDF). It has allowed assessing the condition of the blood flow and detecting the features of the changes of the microcirculation during the with bated breath. The obtained results have shown that the high-amplitude of LDF with the expressed vasomotor' waves has predominated in many students mainly. It has been revealed that the different level of the reactivity during the test with the with bated breath has been due to the individual-typological peculiarities of the blood microcirculation. The different levels of the reactivity depend on the vascular tone. Therefore, smaller meaning of the decrease of the blood flow during the bated breath in the examined students with the hypoemic type of the microcirculation is due to the increased initial tone of the capillaries. In the examined students with the hyperemic type of the microcirculation, in contrast, smaller size of the decrease of the blood flow with the bated breath is associated with the decreased vascular tone. Thus, the reactivity of the capillary blood flow in the examined students for the reaction to the test with the bated breath has been characterized with the sufficient level of the sympathetic influences in the regulation of the tissue blood flow.
Keywords: Blood microcirculation, laser Doppler of low flowmentry (LDF), reactivity of tissue blood flow
Introduction
The important place during the diagnosis of the functional state of the human's organism is the research of the blood microcirculation. The state of metabolism and the functioning of some organs is directly determined with the adequate state of the blood microcirculation. On the other hand, some pathological process proceeds with the different changes in the microcircu-latory channel. Therefore, it is obvious that the changes in the system of the blood microcirculation are closely correlated with the changes in the central hemodynamics [9]. This allows using the data of the criteria in the assessment of the general physical development and the state of the human's health.
Today, the world practice of the study of the blood microcirculation is more often based on the researches of the blood microcirculation during the pathological processes: Lenasi H. to resolve the mechanisms involved in adaptations to exercise training as well as the exact contribution of various endothelial vasodilators to the regulation of vascular tone in human skin microcirculation [6]; Dunaev A., Sidorov V., Stewart N., Sokolovski S., Rafailov E. to address the difficulties in standardising measurement of cutaneous blood micro-dynamics caused by high variability [2]. The assessment of the level of the blood microcirculation in the healthy people in the process of the ontogenesis has been researched by Kozlov V. I. [3, 4], Lytvyn F. B., Morozov M. V.; Tikhomirova I. A., Baboshin N. V., Terekhin S. S. to study of microcirculation parameters in practically healthy adults in a single-stage study and in a prospective study in children [7, 10] and others.
At the moment, one of the main methods of the research of the blood microcirculation is Laser Doppler
flowmetry (LDF), it is a method of the integrated noninvasive assessment of the state of the microcirculatory hemodynamics in the capillaries and it is the actual method of the diagnostics of the microcirculatory disorders [1, 8]. Despite the actuality of the research of the processes of the blood microcirculation, to date, there are no normative indicators of the parameters of the capillary blood flow in the healthy people during the use of the LDF method.
Thus, the question of the individual-typological peculiarities of the blood microcirculation, its reactivity during the influence of different factors in adolescent ages remains the actual for the study.
The purpose of the research is to reveal the individual-typological peculiarities of the reactivity of student' s capillary blood flow and to trace the change of the indicators of the blood microcirculation during the test with the bated breath.
The method of laser doppler flowmetry
123 healthy boys and girls at the age of 17-20, the volunteers-students have been examined who study at Bogdan Khmelnitsky Melitopol State Pedagogical University and live permanently in the South-East of Ukraine. The research has been conducted in accordance with the modern requirements of the bioethics.
With the purpose of the study of the functional state of the blood microcirculation, the method of laser Doppler flowmetry (LDF) has been used [4, 5]. LDF was performed with the laser blood flow analyzer "LACC-01" with the laser source of the radiation at the wavelength of 0.63 ^m. The head of the optical probe (sensor of the device) has been fixed on the ventral surface of the fourth finger.
For the determination of the reactivity of the micro-vessels to the test with the bated breath after the record of the initial blood flow, the examined students have been asked to take a deep breath and hold it for 15 seconds. During the deep breath there was an increase of the venous return to the heart. It has led to the spasm of the vascular vessels, as a result of which the level of the blood microcirculation has been decreased. After the conducting of the breath test, during the recovery period, bigger amplitude of the vasomotors has been registered than during the rest.
The changes of the blood flow in relative to the initial value have given the grounds to judge about the reactivity of the micro-vessels [3, 4]:
RCF = (PM start / PM min.) x 100%, where (1) RCF - reserve of capillary blood flow, PMstart -initial meaning of tissue blood flow, PMmin. - minimal reduction of the blood flow. Statistic evaluation
The statistical processing of the results of the research has been carried out using the standard Microsoft Excel software product. The assessment of the validity of the information between the data has been carried out according to the Students' t-criterion.
The individual-typological peculiarities of the blood microcirculation
Studying of the individual-typological peculiarities of the blood microcirculation during carrying out LDF-gram record in the students, in most of them the high-amplitude LDF-gram with the expressed vasomotor waves have been mainly registered. The parameter of the microcirculation (PM) of the tissue blood flow has been 9,79 perfuse. The level of the oscillations of the tissue blood flow has been 2,36 perfuse. The coefficient of the variation (Kv) has been 30,73 on the average.
Three types of LDF-grams have been revealed in the examined students, which correspond to the different types of the blood microcirculation.
The first type ("Aperiodic" LDF-gram) has been characterized with the irregular oscillation of the blood flow. This type of LDF-gram has corresponded to the normoemic type of the microcirculation.
The second type ("Monotonous" LDF-gram) has been characterized with the fairly high amplitude. This type of LDF-gram has corresponded to the hyperemic type of the blood microcirculation.
The third type ("Monotonous" LDF-gram with the low parameter of microcirculation) has corresponded to the hypoemic type of the microcirculation, which is characterized with the reduced of the blood flow in the microcirculatory channel and the increased tone of the micro-vessels.
The test with the bated breath
During the carrying out the test with the bated breath in the examined students-volunteers, after the record of the initial level of the blood flow, during the deep breath there has been the increase of the venous return to the heart. So, there is the decrease of the blood supply of the vessels of the venular link. It has been due to the activation of vasoconstrictor fibers of the sympathetic nervous system.
During the bated breath for 15 seconds there is the decrease of the parameter of the microcirculation (pic. 1). This is due to the reaction of the vessels to the activation of the adrenergic fibers, which depends on both the effects of the sympathetic innervation and the reactivity of the vascular wall. So, PM reflects the sympathetic regulation during with the bated breath, which is limited mainly with the neurovascular synapse. After the breath test, during the recovery period, higher amplitude of the vasomotors has been registered than at
rest.
-4 JTI_a_m UÜTTJT.S^_S ^Tfi ce«.
Pic. 1. LDF-gram for a test with bated breath. T1-T2 - initial level; Tn1 - deep breath; T3-T5 - period of bated breath; T4 - maximum reduction of blood flow; T5-T6 - the period of restoration of blood flow.
In parallel with the record of the LDF-gram, its amplitude-frequency analysis has been carried out, which allow detecting the changes in the amplitude-frequency spectrum of the oscillation of the tissue blood flow.
Thus, during the bated breath, the decrease of the low-amplitude oscillations (LF-oscillations and VLF-oscillations) and the strengthening of the high-frequency (HF-oscillations) and the pulse oscillations (CF-oscillations) have been observed. The amplitude of LF-oscillations has decreased by 10-20% of the resting level. The indicators of the contribution to the modulation of the blood flow of the breath (HF-oscillations)
and the pulse (CF-waves) oscillations have increased by 3-4 times.
During the recovery period, the vasomotor activity of LF-oscillations has increased and reached the initial level. There has been the decrease of the intensity of the high-frequency (HF-oscillations) and the pulse oscillations.
The level of the reactivity of the micro-vessels to the test with the bated breath
The conducted researches have revealed the level of the reactivity of the micro-vessels to the test with the bated breath, which depends on the microcirculatory types (Table 1).
Table 1
The peculiarities of the reactivity of the microvascular during the test with the bated breath in the students of 1720 years with the different types of the blood microcirculation (M ± m)
Types of blood microcirculation PMinitial, perf. PMmin, perf. A PMinitial - PMmin, perf. RCF, %
Normoemic type (I type of LDF-gram) 10,82 ± 1,53 5,67 ± 1,11 5,15 ± 0,42 54,94 ± 13,49
Hyperemic type (II type of LDF grams) 17,55 ± 1,31 7,56 ± 1,67 9,99 ± 0,64 26,8 ± 3,4
Hypoemic type (III type of LDF-gram) 2,56 ± 1,08 1,14 ± 0,32 1,42 ± 0,76 38,05 ± 8,43
Notes: PMinitial. - initial meaning of tissue blood flow; PMmin. - minimum meaning of blood flow; PMinitial -PMmin. - difference between initial and minimum meaning of microcirculation parameter; RCF - reactivity of capillary blood flow.
In the examined students with the different types of the microcirculation during carrying out the bated breath, it has been found that the level of the capillary spasm is most expressed in the students of the normoe-mic type of the blood microcirculation (I type of LDF-grams). In students with the I type of LDF-grams with the bated breath, the level of the blood flow has decreased by 52,4%, which is significantly higher compared with the indicators in the students with the III type of LDF-grams (44,5%) and the II type of LDF-grams (43,1%).
The different levels of the reactivity depend on the tone of the micro-vessels. Therefore, the smaller meaning of the decrease of the blood flow during the bated breath in the examined students with the hypoemic type of the blood microcirculation (III type of LDF-grams) is due to the increased initial tone of the micro-vessels. In the examined students with hyperemic type of microcirculation (II type of LDF-gram), on the contrary, the smaller magnitude of the decrease of the blood flow during the bated breath is associated with the reduced tone of the micro-vessels.
Thus, the different level of the reactivity to the test with the bated breath has been due to the individual-typological peculiarities of the human's blood microcirculation. The highest reactivity of the micro-vessels has been revealed in the students with the normoemic type of the blood microcirculation (54,94%). With the hyperemic type of the microcirculation, the level of the reactivity has been significantly lower (26,8%), compared with other types of the microcirculation. The level of the reactivity in the hypoemic type of the blood microcirculation had the average meaning (38,05%) among the examined students.
Summary
The conducted researches have revealed the level of the reactivity of the micro-vessels to the test with the bated breath, which depend on the microcirculatory types. The different levels of the reactivity depend on the vascular tone. Therefore, smaller meaning of the decrease of the blood flow during the bated breath in the examined students with the hypoemic type of the microcirculation is due to the increased initial tone of the capillaries. In the examined students with the hyperemic type of the microcirculation, in contrast, smaller size of the decrease of the blood flow with the bated breath is associated with the decreased vascular tone. Thus, the reactivity of the capillary blood flow in the examined students for the reaction to the test with the bated breath has been characterized with the sufficient level of the sympathetic influences in the regulation of the tissue blood flow.
The obtained data about the peculiarities of the state of the tissue blood flow have the main theoretical and the practical meaning for the understanding of the mechanisms of the regulation of the different types of the blood microcirculation. The perspectives of the further research are the analysis of the obtained data depending on the type of the blood microcirculation of the examined students during the action of other functional tests.
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