Left coronary blood flow (LCBF), left ventricular oxygen, extraction [(a-v)O₂ ], and myocardial oxygen consumption (MVO₂) were monitored in 10 dogs. HR was paced at 120 bpm and then increased to 180 bpm to elicit a hyperemic response (ΔLCBF). During the hyperemia, the vaso-dilatory response to exogenous adenosine (F_AD) was tested. Twenty min. after injection of aminophylline (100 mg/i.v.), HR was again increased. F_AD was again tested. The pacing-induced increase in MVO₂ (ΔMVO₂) was not affected by aminophylline (P>0.05). However, the slope ΔLCBF/ΔMVO₂ was decreased, and the slope (a-v)O₂ /ΔMVO₂ was increased. F_AD was also decreased and the magnitude of the reduction was correlated with the decrease in ΔLCBF/ΔMVO₂ (r=0.82). These results suggest that adenosine may play an role in coronary functional hyperemia induced by increases in heart rate.
| Identifer | oai:union.ndltd.org:unt.edu/info:ark/67531/metadc504435 |
| Date | 12 1900 |
| Creators | Randall, John Robert |
| Contributors | Jones, Carl E., Sinclair, Richard J., Barker, David J., Harris, Ben G. |
| Publisher | North Texas State University |
| Source Sets | University of North Texas |
| Language | English |
| Detected Language | English |
| Type | Thesis or Dissertation |
| Format | v, 72 leaves: ill., Text |
| Rights | Public, Randall, John Robert, Copyright, Copyright is held by the author, unless otherwise noted. All rights reserved. |
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