Studies on the Interaction of Chyle and Plasma in the Rat

It has been confirmed that during the absorption of olive oil in the rat there is an increase in the ability of the animal's plasma to clear chyle in vitro. The conditions whereby this post‐absorption clearing can best be demonstrated have been described. 2. A comparison has been made between the clearing of chyle by a post‐absorption plasma and by a plasma withdrawn 15 minutes after the injection of 5 units of heparin per kg. of body weight. The two clearing systems have been shown to behave similarly with regard to temperature, pH, and inhibitors such as Triton derivatives, sodium tauroglycocholate and protamine. In both systems, as clearing of the chyle proceeds, fatty acid is released with the subsequent formation of a soluble fatty acid‐albumin complex in the plasma. 3. In normal plasma a 0·85 per cent sodium chloride extract of rat pancreas has been shown to clear added chyle slowly. This clearing is markedly accelerated in the presence of sodium tauroglycocholate. 4. The similarity between the post‐absorption and heparinized plasma‐clearing systems is discussed. It is suggested that the post‐absorption clearing reaction may represent the physiological mechanism for the dissolution of chylomicrons in the blood. If this is the case, it is shown that plasma albumin can play only a transient role as an acceptor of the dissolved lipid.