EXTRACTS OF THE PARS NEURALIS 



inhibiting effect of vasopressor principle (either as purified 

 principle or as a simple extract of the pars neuralis) have 

 been reported in the past few years by Samaan (1935), 

 Handovsky and Samaan (1936), and Walker, Schmidt, El- 

 som, and Johnston (1937). Samaan confirmed previous ob- 

 servations on the lack of effect of renal denervation on di- 

 uresis inhibition due to the hormone. He found that pos- 

 terior-lobe extract could cause very constant effects under 

 standardized conditions. The extract caused no effect on 

 the secretion of urine in dogs receiving repeated large doses 

 of a solution of urea. The other authors reported on the be- 

 havior of the renal blood flow in non-anesthetized dogs and 

 rabbits and in anesthetized dogs as revealed by the thermo- 

 stromuhr. It appears that Handovksy and Samaan injected 

 extract intravenously and found that the renal blood flow 

 might or might not diminish during diuresis inhibition be- 

 cause of the extract. Walker and his colleagues used only 

 non-anesthetized dogs and rabbits into which they injected 

 extract subcutaneously. No change in renal blood flow oc- 

 curred in association with the inhibition of diuresis. 



If a large enough dose of vasopressor principle is injected 

 subcutaneously into the non-anesthetized animal, hydremia 

 is observed as in the experiments of Yanagi (1936). The 

 author also found that the concentration of K in plasma is 

 increased'^ and suggested that vasopressor extract brings 

 about a transfer of water and K from the interior of cells 

 to the extracellular fluid. '-^ Anemia due to the injection of 

 large doses of posterior-lobe extract was first reported by 

 Dodds and his colleagues who used rabbits. It can also be 

 produced in normal or hypophysectomized guinea pigs (Mc- 



"2 According to Blazso (1936), this change is observed in anesthetized animals, 

 whereas the opposite change — i.e., decreased concentration of K in serum — takes 

 place in the absence of anesthesia. 



'^ The skin, which is important as a depot for chlorine, is believed by Toxopeus 

 (1935) t^o deposit less of the element after the administration of NaCl if posterior- 

 lobe extract also is injected. In addition, the author studied the chlorine of muscle 

 without much success. 



[267] 



