Collection Occupational hygiene, Issue 29, 1993 year
Influence of metal compounds on some extracardiovasal regulatory mechanisms and myocardial structure
I. M. Trakhtenberg, V. A. Tychinin, G. E. Versh, T. N. Pokrovskaya
doi
Institute of Occupational Medicine, Kiev
The complex subordination of the cardiovascular system to all aspects of the body's life, without exception, is realized in the hemodynamic work of the heart and blood vessels, which creates optimal conditions for all functions of the body in the diversity of its metabolism. In this case, the main thing is that this subordination of the cardiovascular system is mainly carried out through extracardiovasal mechanisms of regulation, which determine all the hemodynamic features most characteristic in the human and animal body. Therefore, when assessing the possible cardiovasotoxicity of certain exogenous chemical factors, the study of the influence of these factors on extracardiovasal regulation mechanisms should be considered as an important link in the development of this problem.
Among the neurogenic extracardiovascular mechanisms of regulation of the functioning of the cardiovascular system, reflexogenic zones of blood vessels are of great importance. It is known that among the reflexogenic zones of blood vessels, the carotid sinus zone is the most studied. It should be noted that the neurogenic structure of the press-depressor reflexes, realized from the side of the carotid sinus zone, is very complex. Suffice it to point out that the innervation of the carotid sinus zone is represented by the glossopharyngeal, vagus and sympathetic nerves. The central neuronal links in the construction of these reflexes are also complex. However, the study of their structural and functional organization was not included in the task of our research, but did not exclude a certain theoretical and practical significance of elucidating the effect on these reflexes of priming experimental animals, in particular, various metal salts. Along with this, taking into account the importance of sympathetic mechanisms in extracardiovasal regulation, we investigated the effect of metal compounds on the synaptic transmission of electrical activity in the upper cervical sympathetic ganglion of rats.
We found that salts of mercury, copper and cadmium caused inhibition of pressor reflexes initiated from the side of the carotid sinus zone. All metal salts that were used in our studies had a depressing effect on depressor reflexes. The salts of lead, mercury, and manganese had the greatest ganglion blocking effect; smaller - salts of chromium, cadmium and copper. Along with functional impairment of extracardiovasal regulation, pronounced changes in the histological structure of the myocardium were noted to varying degrees. The data obtained, deepening the understanding of the mechanism of the cardiovasotoxic action of heavy metals, should be taken into account in the experimental and clinical analysis of cardiovascular pathology, in the selection of appropriate indicators and tests in the process of substantiating the hygienic standards for the permissible metal content in the air of the working area.