344 EXPERIMENTAL PHARMACOLOGY 



bulb is drawn full of the solution and the point of the 

 cannula is inserted into the cut end of the renal artery. 

 The cannula can be held in temporarily while the bulb is 

 squeezed with a moderate but firm pressure. The blood is 

 soon flushed out of the kidney vessels. Cannula s are then 

 quickly tied in the renal artery, vein and ureter. The 

 kidney is transferred to the small chamber shown in the 

 upper left hand corner of Fig. 298. This chamber is made 

 of a large, deep metal pill box having a notch cut out of 

 the upper side. Through this notch the three cannulas are 

 passed and then the broad rubber band (which was al- 

 ready around the box) is slipped over the notch while the 

 three cannulas in order are passed through holes (air 

 tight) made in the rubber band. The lid is then placed on 

 the box and the rubber band is slipped over the seam be- 

 tween the lid and the box proper thus making the cham- 

 ber air tight. The box is then connected up as shown in the 

 picture and the stock solution is started through the tubes 

 (from which all air has been previously expelled). The 

 motor is started and the pressure bottle is raised to a 

 height just sufficient to give the maximum excursion to 

 the tambour pointer at each pulsation of the fluid in the 

 tubes. The solution passes through the kidney slowly and 

 fresh (warm) solution should be run down into the tubes 

 occasionally. 



When all adjustments are made take one-half inch of 

 normal record and then with a hypodermic syringe inject 

 some adrenaline solution in the tube above the artery as 

 illustrated. A response should be obtained at once on the 

 drum if the circulation through the kidney is good. Wait 

 for the kidney to expand again. How do you explain these 

 results! As soon as the contraction wears off (or a little 

 before) inject one or two cubic centimeters of sodium 

 nitrite solution (one-half per cent) into the rubber tube. 

 Xote the effect when this reaches the kidney. Explain the 

 results in full. 



