To determine whether muscle contractions can increase muscle blood flow independently from metabolic factors, we isolated the diaphragmatic vasculature of 16 anesthetized and mechanically ventilated dogs. Phrenic inflow (Qphr) was controlled with a constant pressure source and the pressure (Pa) was decreased in steps to obtain the pressure-flow relation (P-Q). The vasculture was maximally vasodilated and contractions occurred spontaneously (n = 6) or were induced by twitches (n = 12) or tetanic trains (n = 7). The P-Q relations with contractions were compared to those with vasodilatation alone. With spontaneous contractions, the pressure intercept decreased from 47.35 $ pm$ 17.44 to 33.77 $ pm$ 16.82 mmHg (p $<$ 0.05) and the slope remained unchanged so that at Pa = 100 mmHg, Qphr increased from 36.22 $ pm$ 34.85 to 43.91 $ pm$ 38.22 ml/min/100g (p $<$ 0.05). Flow increased slightly with twitches but not with trains. We also elicited twitches, 12/min and 60/min trains in vascularly isolated gastrocnemius muscles (n = 6) and found no change in flow. In conclusion, the muscle pump has only a small effect on muscle blood flow.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.60010 |
| Date | January 1990 |
| Creators | Naamani, Randa |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (School of Physical and Occupational Therapy.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001213097, proquestno: AAIMM67692, Theses scanned by UMI/ProQuest. |
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