Using Hyperspectral Near-Infrared Spectroscopy And Diffuse Correlation Spectroscopy To Monitor The Effects Of Phenylephrine In The Microcirculation, Laura Mawdsley

Electronic Thesis and Dissertation Repository

The microcirculation is the site of oxygen exchange in the body, and little work has been done to determine if different microvascular beds respond similarly to a simultaneous vascular challenge. A hybrid microvascular monitoring device was developed that uses hyperspectral near-infrared spectroscopy and diffuse correlation spectroscopy to simultaneously monitor the brain and skeletal muscle. Experiments were conducted on Sprague Dawley rats (n=6, 156g±6.4g) to discern the effect that phenylephrine (0.1 mL bolus, 10 mg/kg) has on the mean arterial pressure (MAP), hemoglobin concentration, and blood flow in each microvasculature. Hemoglobin concentration increased by 2.1±0.2 mmol in the brain, and decreased …

Delineating The Skeletal Muscle-Microvessel Regeneration Program After Ischemic Injury, Jason J. Lee

Electronic Thesis and Dissertation Repository

Understanding the cellular processes involved in skeletal muscle regeneration after damage is critical to advancing translational efforts toward the development of targeted therapeutics. The purpose of this thesis was to ascertain the dynamic interplay between regenerating muscle and regenerating blood vessels after ischemic injury.

First, using a novel systematic investigation of a widely used preclinical mouse model of limb ischemia, I generated a detailed atlas of muscle injury zones and angiogenesis zones in C57BL/6 mice subjected to femoral artery excision. This uncovered previously unrecognized regional variability and an exclusive relationship between angiogenesis and actively regenerating muscle zones. Then, an unbiased, …

Experimental, Theoretical, And Translational Studies Of Rbc Distribution In Capillary Networks, Asher Mendelson

Electronic Thesis and Dissertation Repository

The purpose of this thesis was to evaluate the physiology of red blood cell (RBC) distribution in skeletal muscle capillary networks. Because this is the terminal site of oxygen exchange in the microcirculation, characterization of this fundamental process informs an understanding of how microvascular blood flow regulation matches oxygen supply with local tissue demand. Prior studies in this field have focused on small groups of capillaries, and have not linked capillary network structure with functional measurements, nor evaluated the temporal complexity of RBC distribution over physiologically-relevant scales. It is also unclear how the functional units called capillary modules – comprised …