ABSTRACT
Blood is withdrawn from, crossed, and reinserted into pairs of unanesthetized rats through chronic intravenous silicone rubber cannulas. This method provides a means of accurately monitoring the volume of blood mixed and permits behavioral tests immediately following blood mixing. Mixing the blood of unanesthetized rats is typically achieved by means of a parabiotic preparation. This technique which has been used successfully in research on a variety of problems has, however, one major limitation, which is that it is not possible to quantify resulting effects. The technique is being used to investigate the possible role of blood factors in regulating food intake in rats. Chronic intravenous silicone rubber cannulas are inserted into the right external jugular vein of rats. These cannulas are brought under the skin and project through an incision made on the back of the rat.
