UTERINE CONTRACTIONS 383 



tain ergamine (ten cubic centimeters equal one milligram) 

 and pituitrin (one cubic centimeter to five cubic centimeters 

 of water Parke, Davis & Company's preparation is usually 

 satisfactory, but several other extracts are on the market). 



The metal box in which the animal is placed is now filled 

 with 0.9 per cent salt solution which is thereafter kept at 

 39 C. by a bunsen burner. This prevents exposure of the 

 viscera to the cold air and avoids drying of the tissues. 



The abdomen is now opened by a long median incision 

 and the intestines and bladder are pulled gently to one side 

 and fastened beneath the salt solution, thus exposing the 

 uterine horns. One of these is followed up to the ovary 

 which is gently dissected loose from its attachments (using 

 great care not to disturb the blood-vessels) and the distal 

 end of the uterine horn may also be freed a little from the 

 body wall to permit freedom for its movements if contrac- 

 tions occur. A myocardiograph (Cushny's, Wigger's, etc., 

 or Fig. 141 ) is now placed down over the abdomen. A small 

 round needle is used to pass two stitches of fine thread 

 through the uterine horn about one inch apart. These 

 stitches are used to attach the levers of the myocardiograph 

 to the uterine horn. A very light recording lever (heart 

 lever or light muscle lever) is attached to the myocardio- 

 graph and arranged to write on the drum above (and 

 slightly to the left of) the blood-pressure record. The lever 

 is weighted as nearly as can be estimated to suit the 

 strength and tone of each uterine horn. 



When all adjustments are made a normal record is taken 

 and then one-half cubic centimeter (for a full grown cat) 

 of the pituitary solution is injected. Do you get a rise in 

 blood-pressure? You should do so and this rise lasts for a 

 considerable time. Wait for the curve (blood-pressure) to 

 come back to normal. (Inject a larger dose if necessary to 

 get a good record.) Did you get a uterine contraction? 

 What explanation can you offer? Does this have any clini- 

 cal significance? 



