19th Annual Student Research Conference
Interdisciplinary
Microvascular PO2 (PO2m) On-Kinetics and Tension Development in the Rat Diaphragm
Carl E. Giacchi*, Angela M. Ware, and Michael T. Paddock
Dr. Willaim Sexton (A.T. Still University) and Dr. Laura Fielden, Faculty Mentors
The purpose of this study was to develop a model to investigate the relationships between oxygen delivery, oxygen consumption and fatigue within the rat diaphragm. We measured PO2m (phosphorescence quenching) and muscle tension (using a force transducer) during electrically-stimulated contractions in the denervated medial costal diaphragm (MCD). In the quiescent MCD at in vivo length, PO2m was 52±2 mmHg and tension was 36±8 g/g. During 1 Hz contractions, PO2m fell to 23±2 mmHg with a mean response time (MRT) of 13±1 s. Peak tension averaged 91±13 g/g with no evidence of fatigue. During the 1 Hz to 4 Hz transition, PO2m fell further to 13±3 mmHg with a MRT of 10±2 s. Peak tension was initially unchanged, but fell 22±4% by the end of contraction period. This model permits measurement of PO2m and contractile tension in the diaphragm, thus enabling further assessment of diaphragm function in normal and disease states.
Keywords: Diaphragm, Tension, PO2, Rat
Topic(s):Sigma-Xi
Presentation Type: Poster
Session: 60-79
Location: OP Lobby and Atrium
Time: 4:15