Sympathetic control of the coronary circulation during trigeminal nerve stimulation in humans

• Published in: European journal of applied physiology Vol. 123; no. 9; pp. 2063 - 2071
• Main Authors: Prodel, Eliza, Cavalvanti, Thiago, Divino, Beatriz, Rocha, Helena N. M., Nobrega, Antonio C. L.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.09.2023; Springer Nature B.V
• Subjects: Biomedical and Life Sciences; Biomedicine; Blood Flow Velocity - physiology; Blood pressure; Blood Pressure - physiology; Cold stimuli; Coronary Circulation - physiology; Coronary Vessels - innervation; Female; Heart rate; Heart Rate - physiology; Human Physiology; Humans; Male; Occupational Medicine/Industrial Medicine; Original Article; Prazosin; Propranolol; Sports Medicine; Sympathetic Nervous System - physiology; Trigeminal Nerve; Coronary; Blood velocity; Trigeminal nerve; Circulation
• ISSN: 1439-6319; 1439-6327; 1439-6327
• DOI: 10.1007/s00421-023-05208-1

Purpose We sought to investigate the sympathetic mechanism controlling coronary circulation during trigeminal nerve stimulation in healthy women. Methods The protocol consisted of 3 min of trigeminal nerve stimulation (TGS) with cold stimuli to the face, in two conditions: (1) control and β-blockade (oral propranolol), and (2) control and α-blockade (oral prazosin). Results Thirty-one healthy young subjects (women: n  = 13; men: n  = 18) participated in the study. By design, TGS decreased heart rate (HR), and increased blood pressure (BP) and cardiac output (CO). Before the β-blockade coronary blood velocity (CBV—Δ1.4 ± 1.3 cm s −1 ) increased along with the decrease of coronary vascular conductance index (CVC i —Δ-0.04 ± 0.04 cm s −1  mmHg −1 ) during TGS and the β-blockade abolished the CBV increase and a further decrease of CVC i was observed with TGS (Δ-0.06 ± 0.07 cm s −1  mmHg −1 ). During the α-blockade condition before the blockade, the CBV increased (Δ0.93 ± 1.48 cm s −1 ) along with the decrease of CVC i (Δ-0.05 ± 1.12 cm s −1  mmHg −1 ) during TGS, after the α-blockade CBV (Δ0.98 ± cm s −1 ) and CVC i (Δ-0.03 ± 0.06 cm s −1  mmHg −1 ) response to TGS did not change. Conclusion Coronary circulation increases during sympathetic stimulation even with a decrease in heart rate.