Numerical Simulation of Oxygen Delivery to Muscle Tissue in the Presence of Hemoglobin-Based Oxygen Carriers

Abstract

This work represents a culmination of research on oxygen transport to muscle tissue, which takes into account oxygen transport due to convection, diffusion, and the kinetics of simultaneous reactions between oxygen and hemoglobin and myoglobin. The effect of adding hemoglobin-based oxygen carriers (HBOCs) to the plasma layer of blood in a single capillary surrounded by muscle tissue based on the geometry of the Krogh tissue cylinder is examined for a range of HBOC oxygen affinity, HBOC concentration, capillary inlet oxygen tension (pO(2)), and hematocrit. The full capillary length of the hamster retractor muscle was modeled under resting (V(max) = 1.57 x 10(-4) mLO(2) mL(-1) s(-1), cell velocity (v(c)) = 0.015 cm/s) and working (V(max) = 1.57 x 10(-3) mLO(2) mL(-1) s(-1), v(c) = 0.075 cm/s) conditions. Two spacings between the red blood cell (RBC) and the capillary wall were examined, corresponding to a capillary with and without an endothelial surface layer. Simulations led to the following conclusions, which lend physiological insight into oxygen transport to muscle tissue in the presence of HBOCs: (1) The reaction kinetics between oxygen and myoglobin in the tissue region, oxygen and HBOCs in the plasma, and oxygen and RBCs in the capillary lumen should not be neglected. (2) Simulation results yielded new insight into possible mechanisms of oxygen transport in the presence of HBOCs. (3) HBOCs may act as a source or sink for oxygen in the capillary and may compete with RBCs for oxygen. (4) HBOCs return oxygen delivery to muscle tissue to normal for varying degrees of hypoxia (inlet capillary pO(2) < 30 mmHg) and anemia (hematocrit < 46%) for the hamster model.

Interactions of arene ruthenium metallaprisms with human proteins

“…Cytosolic proteins also possess important functions: cytochrome c is involved in apoptotic pathways, 42 while ubiquitin is relevant in posttranslational modifications together with the proteasome system, 43 and myoglobin is the primary oxygen-carrying pigment of muscle tissues. 44 …”

Simulation of NO and O2 transport facilitated by polymerized hemoglobin solutions in an arteriole that takes into account wall shear stress-induced NO production

“…Patton and Palmer [57] predicted in a model of O 2 transport in a capillary that the release of O 2 from RBCs and HBOCs is affected by the HBOC/RBC O 2 affinity, cooperativity and HBOCs can compete with RBCs for O 2 and behave as sink for O 2 depending on the relative O 2 saturation of the RBCs and HBOCs. Our simulation results showed that the O 2 consumption rate, which was affected by the NO production rate, played a more important role in regulating the rate of O 2 delivery.…”

“…The biophysical properties of PolyHbs and RBCs used in this work are listed in Tables 1 and 2. The diffusivities of PolyHbs and other HBOCs were calculated using equation 35, while the diffusivity of Hb encapsulated within RBCs was estimated using equation 36 [57]. We compared our results to simulations performed with the commercially available PolyHb Oxyglobin® and cell-free bHb.…”

Identification of Novel Metabolic Proteins Released by Insulin Signaling of the Rat Hypothalmus Using Liquid Chromatography-Mass Spectrometry (LC-MS)

“…The branched chain aminotransferase initiates in muscle and yields Nicotinamide Adenine Dinucleotide (NADH) and 1,5-dihydro-flavin adenine dinucleotide (FADH2) which can also be utilized for ATP generation 9,11) . Others are linked with mitochondrial import and oxygen transport 2,13) . To confirm that these proteins were from the secretome, we did western blot and obtained clear bands in the expected sizes for each 3) .…”