Platelets Do Not Alter Flow-Mediated Dilation or Arterial Conduction in vivo

• Published in: Journal of vascular research Vol. 58; no. 4; p. 231
• Main Authors: Ruane-O'Hora, Therese, Markos, Farouk
• Format: Journal Article
• Language: English
• Published: Switzerland 01-07-2021
• Subjects: Animals; Arterioles - physiology; Blood Platelets - physiology; Female; Iliac Artery - physiology; Platelet Count; Regional Blood Flow; Stress, Mechanical; Sus scrofa; Vasodilation; Shear stress; In vivo; Flow-mediated dilation; Platelets; Vascular conductance
• ISSN: 1423-0135
• DOI: 10.1159/000516045

The aim of this study was to investigate whether platelets contribute to shear stress and vascular conductance in the iliac vascular bed in vivo. Flow-mediated dilation of pig iliac was induced by downstream injection of acetylcholine (50 μg), and separately, conductance (ΔF/ΔP) was calculated. This was carried out before and after removal of 1 L of arterial blood in 240 mL increments, and each 240 mL was spun in a centrifuge (1,500 rcf for 7 min); platelet-rich plasma was replaced with equal volume of heparinised saline and reinjected. The circulating platelet count fell from 369 × 109/L (n = 5) to 165 × 109/L (p = 0.01; n = 4; Student's unpaired t). An increase in flow led to an increase in the iliac diameter by 0.49 ± 0.03 mm (mean ± SEM) before platelet reduction and 0.55 ± 0.05 mm after (p = 0.36, Student's paired t, n = 5); the change in arterial conductance was also not significantly affected by platelet reduction, control: 1.44 ± 0.34 mL/min/mm Hg, after platelet reduction: 1.39 ± 0.04 mm (p = 0.55, Student's paired t, n = 4). Therefore, platelets do not contribute to shear stress or conductance in vivo.