Acta Vet. Brno 2012, 81: 281-286
Myoelectric activity of the muscular layer of the abdominal aorta in pigs in vivo
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.
