Microcirculatory response of the pancreas to feeding, sham feeding, and truncal vagotomy in conscious dogs.

Abstract

In this study, changes in the microcirculatory dynamics of the pancreas in response to normal feeding, sham feeding, and truncal vagotomy were investigated to elucidate the involvement of a neural mechanism in the physiological modulation of pancreatic blood flow in the conscious state. Continuous measurement of changes in the microcirculation of the pancreas was performed in conscious dogs by the thermoelectric method. A meat meal was given to six normal dogs, seven dogs constructed with external esophagostomy (sham feeding), and four dogs with truncal vagotomy. In response to normal feeding, pancreatic blood flow attained the peak increase of 65.2 +/- 6.2%, showing a significant and biphasic response until approximately 120 min. After sham feeding, pancreatic blood flow was significantly increased with peak values of 89.0 +/- 19.0%, but thereafter showed a rapid decrease, returning to the basal level already at 7.2 +/- 1.1 min. Although truncal vagotomy significantly and greatly reduced the peak increase of pancreatic blood flow to 28.2 +/- 5.1%, blood flow showed still a significant and sustained elevation above basal. This study provides evidence for the involvement of the neural mechanism in the physiological modulation of the microcirculation of the pancreas in the conscious state. The results strongly suggest that the cephalic phase of the increase in pancreatic blood flow is vagally mediated.