THE PITUITARY BODY 



of plasma or of plasma proteins due to the administration of 

 histamine, incompatible blood, etc. 



According to Thienes and Hockett (1930-31), the sub- 

 cutaneous injection of posterior-lobe extract lessens the rate 

 of absorption of a number of substances from the gastro- 

 intestinal tract: glucose (rat), iodides (rabbit, rat, man), 

 morphine or an extract of cannabis (dog), and strychnine 

 (rabbit). Gellhorn (1933) concluded that the glucose permea- 

 bility of the intestine of the frog is not affected by perfusing 

 the vessels of the gut with a solution containing posterior- 

 lobe extract provided that the perfusion-rate is kept con- 

 stant. 



The efect of extracts of the pars neuralis on the smooth 

 muscle of other structures, i. The uterus. — No accurate com- 

 parative studies of the sensitivity of the isolated uterus 

 toward the oxytocic principle have been made. The isolated 

 uterus of the immature guinea pig appears to be one of the 

 most sensitive. 5 The oxytocic principle is usually considered 

 to cause changes in the uterus (increased rate of rhythmic 

 contractions if present, increased tone, contraction) by "act- 

 ing" directly on the smooth musculature. The effect of the 

 principle on the uterus may be sensitized by substances like 

 serum albumin, BaCL, or quinine (Frohlich and Paschkis, 

 1926; Schiibel, 1928).^ Probably the oxytocic substance and 

 histamine act differently on the contractile mechanism of the 

 uterine musculature. 



The injection of the oxytocic principle into the unan- 

 esthetized rabbit with a fistula of the uterus, by means of 

 which tracings of the movements can be secured, causes a 

 sustained contraction of the uterus followed by the normal 

 rhythmical movements present before the injection. How- 

 ever, after the injection of a posterior-lobe extract, the phase 



5 The fallopian tube (man, rabbit, cow) is very insensitive (Kammerhuber, 1932). 



* Extracts of the urine of both pregnant and non-pregnant women may cause 

 sensitization (Illingworth, Marshall, and Robson, 1932). 



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