AJP - Gastrointestinal and Liver Physiology, Vol 242, Issue 6 596-G602, Copyright © 1982 by American Physiological Society
Pancreatic circulation: intrinsic regulation
P. R. Kvietys, J. M. McLendon, G. B. Bulkley, M. A. Perry and D. N. Granger
The purpose of the present study was to characterize the intrinsic
mechanisms involved in the regulation of blood flow and oxygenation in the
totally isolated, perfused canine pancreas. Arterial pressure, venous
outflow pressure, blood flow, arteriovenous oxygen difference, and
capillary filtration coefficient were measured during graded arterial
pressure reductions and venous pressure elevation. Reductions in arterial
pressure caused pancreatic blood flow and vascular resistance to decrease,
whereas venous pressure elevation resulted in a decreased blood flow and
increased vascular resistance. The reductions in blood flow produced by
arterial and venous pressure alterations were associated with increases in
oxygen extraction and capillary filtration coefficient. During the same
pressure perturbations, oxygen uptake remained constant between blood flows
of 40-100 ml.min-1.100 g-1, yet decreased progressively as blood flow was
reduced below 40 ml.min-1.100 g-1. Arterial occlusion resulted in a
postocclusive reactive hyperemia, the magnitude of which was related to the
duration of occlusion. The findings of this study suggest that intrinsic
regulation of pancreatic blood flow can be attributed to both metabolic and
myogenic mechanisms. Resistance and exchange vessels both appear to play a
role in the regulation of oxygen delivery to the pancreatic parenchyma.
