Effect of Circulating Somatostatin Upon the Gastrointestinal Tract Function

Abstract

After an overnight fast, 17 dogs weighing 11-21 Kg received protein-fat meal in a conscious state and three hours after the ingestion, the lymph was obtained through a catheter inserted in the thoracic duct under neuroleptanalgesia. In fasting and postprandial states, the levels of flow rate, triglycerides (TG) concentration, and TG content in the lymph were significantly reduced after cyclic somatostatin infusions at rates of 50ng/min and 5μg/min through the portal and the femoral veins. The attenuated levels of those in fasting were approximately 80-90% of the values in preinfusion period at a physiological infusion rate (50ng/min) and 77-82% at a pharmacological rate (5μg/min), whereas, the levels were 79-90% of those in the preinfusion values at 50 ng/min rate and 56-85% at 5μg/min infusion rate in the postprandial state. The somatostatin infusions at the rates through either the portal or the femoral vein induced almost identical levels of the attenuating effects on the thoracic duct lymph.
These results suggest the possibility that circulating somatostatin from the pancreas or other organs in the portal vein region might have a physiologic influence upon the nutrient entry from the gastrointestinal tract.