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

Area of Science:

• Cardiovascular Physiology
• Hematology

Background:

• Platelets play a role in hemostasis and thrombosis.
• Their contribution to vascular regulation under shear stress is not fully understood.

Purpose of the Study:

• To investigate the in vivo role of platelets in shear stress and vascular conductance within the pig iliac vascular bed.

Main Methods:

• Flow-mediated dilation and arterial conductance were measured in pig iliac arteries.
• Circulating platelet counts were reduced by removing and replacing platelet-rich plasma with heparinized saline.
• Measurements were taken before and after platelet reduction.

Main Results:

• Platelet reduction significantly decreased circulating platelet count (369 to 165 × 10^9/L).
• No significant differences were observed in flow-mediated iliac diameter increase (0.49 vs. 0.55 mm) or arterial conductance (1.44 vs. 1.39 mL/min/mmHg) after platelet reduction.

Conclusions:

• Platelets do not appear to contribute to shear stress-mediated vasodilation or vascular conductance in the pig iliac vascular bed in vivo.