Spontaneous contractile dynamics of the vascular smooth muscle of the external carotid artery

Abstract

Introduction: The external carotid is a muscle artery irrigating all components of the masticatory system, so that the regulation of the contractile dynamics of its vascular smooth muscle is important. Objective: To describe the spontaneous contractile dynamics of the vascular smooth muscle of the external carotid artery. Methods: An experimental investigation was carried out in the Oscar Langerdorff Physiology Institute from the Medicine Faculty at Rostock University, Germany, from October to December 2018, in which 60 rings of the external carotid artery obtained from 10 adult Wistar rats from both sexes. An helical cut was made to each ring and they were placed in an organ bath, to be registered, then, the spontaneous strain developed by the vascular smooth muscle against a charge of 1 g, during different time intervals was registered. Results: The records from the spontaneous contraction-relaxation of the vascular smooth muscle in the external carotid artery fluctuated within a narrow range of strain figures, with maximum values of 8.48 ± 0.03 and minimum of 8.33 ± 0.03, and a difference of 0.08 mN/g of muscle. Average strain values in each time interval were very closed, with standard deviations which evidenced a very small data dispersion regarding the mean. The average general registered strain was 8.40 ± 0.032 mN/g. Conclusions: The spontaneous contractile dynamics developed by the vascular smooth muscle of the external carotid artery showed an irregular progression in time, with average strain values fluctuating between 5-10 mN/g of muscle.

Keywords

• arteria carótida externa
• músculo liso vascular
• dinámica contráctil
• ratas wistar.