Pharmacologic vasodilation increases muscle perfusion and muscle protein anabolism similarly in elderly and young

Abstract

We examined muscle protein metabolism in healthy young and elderly during pharmacologic vasodilation of the lower limb vasculature in combination with increased amino acids delivery. We obtained femoral arteriovenous blood samples and v. lateralis muscle biopsies during a primed continuous infusion of L‐[ring‐13C6] Phenylalanine. Muscle protein kinetics were measured in the basal state (BAS) and during a 180 min infusion of sodium nitroprusside (SNP) and amino acids (Premsol 10%) (SNP+AA). Skeletal muscle microvascular recruitment and flow were measured during BAS and SNP+AA using contrast‐enhanced ultrasound (CEU). SNP increased capillary recruitment and microvascular blood flow to a similar extent in both age groups (P ≤ 0.05). Phenylalanine net balance and model derived values for muscle protein synthesis increased significantly during SNP+AA administration, with no differences between age‐groups (P ≤ 0.05). These data demonstrate that an increase in nutritive blood flow in both younger and older individuals facilitates a similar increase in the utilization of amino acids for muscle protein anabolism.