Pancreatic O2 consumption and CO2 output during secretin-induced, exocrine secretion from the pancreas in the anesthetized dog.

Secretin stimulates pancreatic water and CO2 excretion as well as pancreatic blood flow. It has been questioned whether the production (i.e. water and CO2 excretion) is reflected in the input-output difference of nutrients. In pentobarbital anesthetised dogs, pancreatic exocrine secretion was stimulated by secretin (Karolinska), 1 U/kg injected as an i.v. bolus. Secretion was maximally increased at 2 min after the secretin shot and returned to a basal value at between 16 and 32 min after secretin. Blood flow was also maximally increased at 2 min, but decreased to the basal value at between 8 and 16 min. O2 extraction first decreased (at 2 min) and then gradually increased until it was higher than the basal value (at 16 min) and then returned to the basal level (at 32 min). O2 consumption increased quickly, reached a plateau, lasting from 1 to 16 min, and then decreased to the basal level (32 min). CO2 transfer from blood to tissue reached a maximum at 4 min and then decreased to the basal value (at between 16 and 32 min). The curves for CO2 transfer from tissue to pancreatic secretion and for CO2 in the secretion had the same shape. It is concluded that the curve of production (of water and CO2 excretion) parallels the curve of O2 consumption fairly well. The O2 consumption curve did not correlate either with the blood flow curve or with the O2 extraction curve. About one quarter of the excreted CO2 originated from pancreatic metabolism and the remaining three quarters were transferred from blood, through the pancreatic tissue into the secretion.(ABSTRACT TRUNCATED AT 250 WORDS)