EFFECTS OF EXTRACTS OF PARS NEURALIS 



xAccording to Simon (1933), the isolated ileum of the guinea 

 pig can be used as a sensitive means of assaying the vaso- 

 pressor principle. 



3. The gall bladder^ spleen^ and ureters. — xAccording to 

 Schoendube and Kalk and Schoendube (1925-26 — man), 

 Adlersberg and van Goor (1928 — rabbit), and Shi (1933 — 

 dog), the subcutaneous or intravenous injection of a pos- 

 terior-lobe extract often causes a contraction of the gall 

 bladder. Nissen (1932 — man, isolated guinea-pig gall blad- 

 der) believed that this effect is not due to either the oxytocic 

 or the pressor principle. 



De Boer and Carroll (1924) concluded that any reduction 

 in the splenic volume occurring as the result of the injection 

 of a posterior-lobe extract is due to a vasoconstriction. 



Gruber (1928) found that the addition of a posterior-lobe 

 extract to the fluid bathing the isolated ureter (pig) caused 

 an increase in the amplitude and rate of the rhythmical 

 movements. 



4. The heart and smooth muscle of invertebrates. — Hogben 

 and Hobson (1924) performed their experiments on the iso- 

 lated heart of a crab, Maia., on the perfused heart of a bi- 

 valve, Pecten, on the isolated crop of a mollusk, Aplysia, and 

 on the isolated pharynx of an annelid. Aphrodite. In no case 

 did posterior-lobe extract produce any effect (concentration 

 equivalent to about 10 units in 40 cc. of fluid). 



OTHER EFFECTS OF EXTRACTS OF THE PARS NEURALIS 



The efects of the injection of extracts into the lumbar sub- 

 arachnoid space., the cisterna magna., or the lateral ventricles. — 

 The injection of a posterior-lobe extract into the lumbar sub- 

 arachnoid space of the cat or rabbit is followed by a greater 

 rise in blood pressure than that following the injection of a 

 similar dose intravenously. The effect is prevented by liga- 

 tion or section of the cervical cord (Leimdorfer, 1926; Ozu, 

 1928). 



[347] 



