324 INTERNAL SECRETION 



absolute alcohol, treatment of the alcoholic residuum with ether, 

 and solution in sodium chloride. If the substance obtained by 

 this method is injected into the veins, a transient primary hypo- 

 tension is observed, which is probably due to peripheral vasodila- 

 tion and is not preceded by a rise in blood-pressure. This hypo- 

 tension is similar to that obtained by the injection of cholin, but 

 unlike the latter, it is unaffected by atropine. 



Osborne and Vincent next showed that extracts of nervous 

 tissue (brain, spinal cord, peripheral nerves) give rise to a con- 

 siderable transient fall in blood-pressure, which is also unaffected 

 by resection of the vagus and by atropine, and which is brought 

 about by peripheral vasodilation. Contrary to the view expressed 

 by Halliburton, it is certain that this result is in no way due to 

 the action of cholin. 



According to v. Cyon, pituitary extract contains two sub- 

 stances which possess entirely different properties. The one, 

 hypophysin, which is obtained by boiling pituitary extract, has 

 an influence upon the heart; its intravenous injection is followed 

 by groups of slow, strong beats, and this effect persists after 

 resection of the vagi. Extracts obtained at a temperature of 

 38 to 40 C. usually possess a vaso-constrictor effect which v. Cyon 

 believes to be brought about by inhibition of the nervous 

 depressor. 



The effects of pituitary extract in raising pressure and slowing 

 the pulse the latter only where the vagi are intact, however are 

 confirmed by Livon, who includes the hypophysis in the group 

 of the hypertensive glands ; while Silvestri, on the contrary, 

 obtained only a fall in blood-pressure with extract of the posterior 

 lobe. After the injection of a quantity of infundibular extract 

 equal to about one-fifth of the posterior lobe, Gamier and Thaon 

 observed a rapid rise in pressure with slowing of the pulse, 

 followed after ten to twelve seconds by a rapid transient fall in 

 pressure, which was again followed by a marked rise. The 

 slowing of the pulse was not observed after the resection of the 

 vagi. Similar phenomena are described by Salvioli and Carraro, 

 Pal, Lockhart-Mummery, and Legge. 



By means of plethysmographs of different organs, Hallion 

 and Carrion showed that the rise in pressure brought about by 

 pituitary extract is associated with a vasoconstriction in 

 different organs, in the nasal mucosa and thyroid gland more 

 particularly. In the kidney there was, after an initial vaso-con- 

 traction, a continued vaso-dilation. These authors point out the 

 antagonistic effects of pituitary to those of ovarian extract, the 

 latter, as far as their experiments showed, producing a fall in 

 blood-pressure together with a characteristic vaso-dilation in the 

 thyroid gland. 



Quite recently (December 17, 1909), Falta and Ivcovic stated 

 that they injected 2\ c.cm. of an extract obtained from the glandu- 



