Journal of Applied Physiology, Vol 71, Issue 2 583-589, Copyright © 1991 by American Physiological Society

ARTICLES

Regional distribution of blood flow within the diaphragm

A. Brancatisano, T. C. Amis, A. Tully, W. T. Kelly and L. A. Engel
Thoracic Medicine Unit, Westmead Hospital, Sydney, New South Wales, Australia.

We investigated the regional distribution of blood flow (Q) within the costal and crural portions of the diaphragm in a total of eight anesthetized supine mongrel dogs. Q was measured with 15-microns microspheres, radiolabeled with three different isotopes, injected into the left ventricle during spontaneous breathing (SB), inspiratory resistive loading (IR), and mechanical ventilation after paralysis (P). At necropsy, the costal and crural portions of each hemidiaphragm were arbitrarily subdivided along a sagittal plane into five to seven and three sections, respectively. During P, there was a dorsoventral Q gradient within the costal part of the diaphragm. During SB there was a fourfold increase in the gradient of Q. Furthermore, during IR, in which mouth pressures of -16 +/- 4 cmH2O were generated, there was a further increase in the gradient of Q. During both SB and IR, Q to the most ventral portion of the costal diaphragm was 26 +/- 6% less than the peak value. In two dogs, studied prone and supine, there was no difference in the Q gradients between the two postures. Over the dorsal 80% of the costal diaphragm there was also a dorsoventral gradient of muscle thickness, such that the most dorsal part was 54 +/- 2% (n = 5) that of the ventral portion. In contrast, there was no consistent gradient of Q or muscle thickness within the crural diaphragm. Our results demonstrate a topographical gravity-independent distribution of Q in the costal, but not the crural, diaphragm.(ABSTRACT TRUNCATED AT 250 WORDS)

This article has been cited by other articles:

				R. L. Johnson Jr., C. C. W. Hsia, S.-I. Takeda, J. L. Wait, and R. W. Glenny Efficient design of the diaphragm: distribution of blood flow relative to mechanical advantage J Appl Physiol, September 1, 2002; 93(3): 925 - 930. [Abstract] [Full Text] [PDF]

				C. S. H. Sassoon, V. J. Caiozzo, A. Manka, and G. C. Sieck Altered diaphragm contractile properties with controlled mechanical ventilation J Appl Physiol, June 1, 2002; 92(6): 2585 - 2595. [Abstract] [Full Text] [PDF]

				C. C. W. Hsia, S.-I. Takeda, E. Y. Wu, R. W. Glenny, and R. L. Johnson Jr. Adaptation of respiratory muscle perfusion during exercise to chronically elevated ventilatory work J Appl Physiol, November 1, 2000; 89(5): 1725 - 1736. [Abstract] [Full Text] [PDF]

				D. C. Poole, W. L. Sexton, B. J. Behnke, C. S. Ferguson, K. S. Hageman, and T. I. Musch Respiratory muscle blood flows during physiological and chemical hyperpnea in the rat J Appl Physiol, January 1, 2000; 88(1): 186 - 194. [Abstract] [Full Text] [PDF]

				T. A. Wilson, A. M. Boriek, and J. R. Rodarte Mechanical advantage of the canine diaphragm J Appl Physiol, December 1, 1998; 85(6): 2284 - 2290. [Abstract] [Full Text] [PDF]

				W. L. Sexton and D. C. Poole Effects of emphysema on diaphragm blood flow during exercise J Appl Physiol, March 1, 1998; 84(3): 971 - 979. [Abstract] [Full Text] [PDF]

				M. Angelillo, A. M. Boriek, J. R. Rodarte, and T. A. Wilson Theory of diaphragm structure and shape J Appl Physiol, November 1, 1997; 83(5): 1486 - 1491. [Abstract] [Full Text] [PDF]