THE PITUITARY BODY 



Although Inaba (1928), who used cats and rabbits, was 

 unable to observe any vasopressor effect as a result of the 

 injection of a posterior-lobe extract into the cisterna magna, 

 Heller and Kusunoki (1933) and Bouckaert (1934) found that 

 the suboccipital injection of an extract into the dog caused 

 a stimulation of the vasomotor center. A pressor response 

 appeared as early as after an intravenous injection but, unlike 

 that following the latter, was accompanied by no preliminary 

 fall in blood pressure (coronary constriction) or tachyphy- 

 laxis. 



The effects of injections of posterior-lobe extracts into the 

 lateral ventricles have been studied in the rabbit, cat, and 

 dog (Spiegel and Sato, 1924; Inaba, 1928; Henstell," 1933), 

 in the primate (Light and Bysshe, 1933), and in man (Gush- 

 ing, 1 931). The important vasomotor effect is depressor and 

 apparently is due to the vasopressor principle which has 

 usually been given in large doses." From his experiments in 

 man Gushing concluded that the symptoms (vasodilation, 

 sweating, marked lowering of body temperature, lowering of 

 basal metabolism) were in part due to a stimulation of 

 diencephalic parasympathetic nuclei. His data leave unde- 

 cided the question of the specificity of the effects." 



The effects of posterior-lobe extracts on the stomach. — The 

 injection of posterior-lobe extract may inhibit the secretion 

 of gastric juice, particularly the secretion of hydrochloric 

 acid; the experimental data do not indicate that this is an 

 important effect (dog: Hess and Gundlach, 1920; Alpern, 



"Henstell injected the vasopressor principle into the third ventricle of anes- 

 thetized cats. The blood pressure was not affected. 



" In their experiments in the "sooty mangabey" (Cercocebus aethrops). Light 

 and Bysshe injected 20 vasopressor units into the lateral ventricle of animals weigh- 

 ing 2.5-4.5 kg. Dilute acetic acid (equivalent to that used in the extract), the oxy- 

 tocic principle, histamine, or acetylcholine were without effect. 



" Little is known concerning the pharmacology of the parasympathetic centers 

 (e.g., responses to drugs affecting the peripheral parasympathetic nervous system). 

 Gushing could not exclude peripheral effects by other drugs (pilocarpine, atropine) 

 which he used. 



[348] 



