AJP - Heart and Circulatory Physiology, Vol 265, Issue 2 537-H542, Copyright © 1993 by American Physiological Society

ARTICLES

Relationship between capillary and systemic venous PO2 during nonhypoxic and hypoxic ventilation

J. C. Stein, C. G. Ellis and M. L. Ellsworth
Department of Pharmacological and Physiological Science, St. Louis University School of Medicine, Missouri 63104.

We evaluated the relationship between end-capillary and systemic venous PO2 values in the retractor muscle of 14 anesthetized hamsters during both nonhypoxic and hypoxic ventilation to ascertain whether the level of tissue oxygenation could be reliably estimated from the systemic parameter. End-capillary PO2 was estimated from measurements of oxygen saturation in capillaries at the venular end of the network obtained using in vivo video microscopy and computer-aided image-analysis techniques at three different levels of inspired oxygen (0.3, 0.21, and 0.1). Measurements of systemic arterial and venous blood gases were made in conjunction with these capillary determinations. In addition, in a portion of the study we utilized an oxygen microelectrode to determine the PO2 in the first-order venule draining the portion of the muscle containing the capillaries under study. We found that only when the animals were made acutely hypoxic was there any correspondence between the systemic venous and end-capillary PO2 values. In addition, these data provide support for the presence of arteriovenous shunting of oxygen during nonhypoxic ventilation.

This article has been cited by other articles:

				R. G. Evans, B. S. Gardiner, D. W. Smith, and P. M. O'Connor Intrarenal oxygenation: unique challenges and the biophysical basis of homeostasis Am J Physiol Renal Physiol, November 1, 2008; 295(5): F1259 - F1270. [Abstract] [Full Text] [PDF]

				A. S. Golub and R. N. Pittman PO2 measurements in the microcirculation using phosphorescence quenching microscopy at high magnification Am J Physiol Heart Circ Physiol, June 1, 2008; 294(6): H2905 - H2916. [Abstract] [Full Text] [PDF]

				E. G. Mik, T. Johannes, and C. Ince Monitoring of renal venous PO2 and kidney oxygen consumption in rats by a near-infrared phosphorescence lifetime technique Am J Physiol Renal Physiol, March 1, 2008; 294(3): F676 - F681. [Abstract] [Full Text] [PDF]

				P. C. Johnson, K. Vandegriff, A. G. Tsai, and M. Intaglietta Effect of acute hypoxia on microcirculatory and tissue oxygen levels in rat cremaster muscle J Appl Physiol, April 1, 2005; 98(4): 1177 - 1184. [Abstract] [Full Text] [PDF]

				D. J. Saltzman, A. Toth, A. G. Tsai, M. Intaglietta, and P. C. Johnson Oxygen tension distribution in postcapillary venules in resting skeletal muscle Am J Physiol Heart Circ Physiol, November 1, 2003; 285(5): H1980 - H1985. [Abstract] [Full Text] [PDF]

				A. G. TSAI, P. C. JOHNSON, and M. INTAGLIETTA Oxygen Gradients in the Microcirculation Physiol Rev, July 1, 2003; 83(3): 933 - 963. [Abstract] [Full Text] [PDF]

				M. Sinaasappel, C. Donkersloot, J. van Bommel, and C. Ince PO2 measurements in the rat intestinal microcirculation Am J Physiol Gastrointest Liver Physiol, June 1, 1999; 276(6): G1515 - G1520. [Abstract] [Full Text] [PDF]

				H. Kobayashi and N. Takizawa Imaging of Oxygen Transfer Among Microvessels of Rat Cremaster Muscle Circulation, April 9, 2002; 105(14): 1713 - 1719. [Abstract] [Full Text] [PDF]