PRACTICAL EXERCISES 



1149 



2. Comparison of Changes of Tone Produced in Uterus Segments by 

 Different Concentrations of Adrenalin. For this the uterus of a virgin 

 rabbit (full-grown or nearly so), is best, as it is advantageous that the 

 spontaneous contractions should be absent or feeble. Starting always 

 with the segment* in Ringer's or Tyrode's solution replace the solution 

 by adrenalin in different dilutions (i : 10,000,000, i : 50,000,000, 

 i : 1,000,000, etc.), washing off the adrenalin thoroughly with the 

 Ringer's solution, Compare the effect of serum or defibrinated blood 

 obtained from the rabbit itself or from some other laboratory animal 

 with that of a known solution of adrenalin. 



If blood collected from the adrenal veins of an animal is available it 

 should be compared with blood from the same animal taken from the 



Fig. 491. Action on Rabbit's Uterus Segment of Blood Specimens from the Adrenal 

 Veins (of a Dog) with Different Concentrations of Epinephrin, and Comparison 

 with Adrenalin added to Blood. At 28 Ringer's solution was replaced by the 

 second adrenal specimen; at 29 by the third adrenal specimen; at 30 by the fourth 

 adrenal specimen; at 31 by the fifth adrenal specimen; at 37 by the sixth adrenal 

 specimen; at 41 by jugular vein blood. All bloods diluted with 15 volumes 

 Ringer's solution. At 34 adrenalin in jugular blood (i : 2,000,000); at 35 adre.na- 

 lin in jugular blood (i : 3,000,000); at 36 adrenalin in jugular blood (i : 4,000,000) 

 replaced Ringer's solution. The adrenalin bloods after being made up to the 

 concentrations mentioned, were diluted with 15 volumes of Ringer's solution 

 before application to the segment. (Reduced to one-half.) 



general circulation (jugular vein or carotid artery). The tone-increasing 

 power of the adrenal vein blood will be greater than that of the in- 

 different blood, because both the serum and the epinephrin will act in 

 the same sense (Fig. 491). 



3. Partition of Adrenalin between Serum and Corpuscles. Add to 

 100 c.c. of dog's blood 0-5 c.c. of the 1:1,000 solution of adrenalin. 

 Centrifuge a portion of the mixture to obtain clear serum. Centrifuge 

 another portion of the dog's blood to which adrenalin has not been 

 added. Test on rabbit's uterus segments and also on intestine seg- 



* It is best to arrange the segment to record the longitudinal shortening. 



