THE PHYSIOLOGICAL VARIATIONS IN RESISTANCE TO BILE FLOW TO THE INTESTINE

Abstract

Under specially controlled conditions in the healthy unanesthetized dog the resistance offered to the flow of bile through the lower common duct was measured. The average resistance 4-12 hours after a feeding corresponded to the pressure of a column of bile 100-120 mm. high. After a 24-72-hour fast the resistance was such as to support a much higher column of bile, 300 mm. at times. The exhibition of food to the fasting animal usually precipitated a reflex lessening in the resistance to the flow of bile to the intestine; the actual taking of food always brought it about. This was transient and was soon followed by a period of increased resistance lasting 10-30 minutes after food had entered the stomach. There succeeded a drop in resistance which was gradual and fluctuating. An increase in resistance to the flow of bile into the intestine was observed after alkali had entered the stomach, and a decrease after acid had been administered. The sudden changes are attributed chiefly to the activity of the sphincter of Oddi.