Myoelectric activity of the muscular layer of the abdominal aorta in pigs in vivo
| Autor: | Albert Czerski, Wojciech Zawadzki, Willy Hauzer, Stanisław Ferenc, Wojciech Witkiewicz, Jan Gnus, Agnieszka Rusiecka, Maciej Janeczek, K. Ratajczak |
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| Rok vydání: | 2012 |
| Předmět: |
Aorta
lcsh:Veterinary medicine Vascular smooth muscle General Veterinary Electromyography Chemistry VSMC Abdominal aorta Lumen (anatomy) Anatomy contractility Contractility Muscular layer medicine.anatomical_structure Adventitia medicine.artery medicine lcsh:SF600-1100 membrane potential Blood vessel |
| Zdroj: | Acta Veterinaria Brno, Vol 81, Iss 3, Pp 281-286 (2012) |
| ISSN: | 1801-7576 0001-7213 |
| Popis: | The study was conducted on 5 pigs weighing 20–30 kg. Bipolar electrodes were surgically implanted into the muscular layer of the vascular smooth muscle cell of the abdominal aorta just below the renal arteries. Myoelectric activity characterized by the appearance of changes of membrane potential was found. Changes of potential could be divided according to the amplitude, duration and frequency into first-, second- and third-order waves. First-order waves appeared with a mean frequency of 128 ± 14/min. The mean wave amplitude was 0.150 ± 0.03 mV, and the mean duration was 0.43 ± 0.05 s. They were closely correlated with the electrocardiogram and blood pressure changes. Second-order waves appeared with a mean frequency of 15.9 ± 4.4/min. They were characterized by a mean duration of 2.69 ± 1.5 s. The mean amplitude of the discharge was 0.205 ± 0.157 mV for the second-order wave, they were correlated with the animal’s respiratory action. Third-order waves appeared with a mean frequency of 4.03 ± 1.07/ min. They were characterized by a mean duration of 11.81 ± 5.3 s. The mean amplitude of the discharge was 0.345 ± 0.232 mV for the third-order wave and they were associated with the autonomic control of the lumen of the blood vessel. For the first time the usefulness of the electromyography method in monitoring changes in the vascular smooth muscle cell of pig abdominal aorta was proved. Electromyography, membrane potential, VSMC, contractility The function of the abdominal aorta is to transport blood to the smaller arterial vessels under high pressure. It performs this function due to the adaptation of the anatomy and biophysical properties of the vessel wall. Generally, the wall of blood vessels is composed of an endothelial layer, a middle layer containing numerous smooth muscular coat cells with collagen and elastic fibres, and adventitia surrounding the vessel. The biophysical properties of blood vessels are determined by the mutual quantity ratio of these three elements together and the ratio of the vessel wall thickness to the internal radius. The wall of larger arteries is characterized by a low ratio of wall thickness to the internal radius (on average 1 : 6), (Harder et al. 1981). It is dominated by elastic fibres that provide it with considerable tensibility. The presence of smooth muscular tissue in the arteries provides control of the vessel lumen. Muscular coat contraction causes reduction in the crosssection of the vessel which results in increased vascular resistance and blood pressure. The control of the vessel lumen takes place through nerves by the autonomic nervous system and hormonally by the secretion of vasoconstrictor (Guyenet 2006; Grassi et al. 2008). The aim of this research was to study the bioelectric properties of the smooth muscular coat of the aorta in pigs and to interpret the obtained patterns, considering the fact that there is a strong correlation between bioelectric activity and contractility. This work is an |
| Databáze: | OpenAIRE |
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