PHAKMACOLOGY OF HYPOPHYSEAL EXTRACTS 747 



Pharmacology of the Pars Intermedia. The histology of this portion 

 of the hypophysis has been recently studied by Lewis and Maurer (1920). 

 From their report it is evident that there are histological indications of a 

 physiological activity of a secretory glandular nature in this portion of 

 the hypophysis which tends to afford a morphological confirmation of the 

 pharmacodynamical investigations of earlier workers. 



There has been and still is some little controversy over whether or not 

 the pressor, uterine-contracting and milk-secreting stimulating effects 



Fig. 2. Showing the effect upon the blood-pressure of the rabbit following the 

 intravenous injection of pure pars intermedia extract. Time is in seconds. (After 

 Atwell and Marinus, Am. J. Physiol.) 



produced by extracts of the posterior lobe of the hypophysis are due to 

 the simultaneous inclusion in the preparations of extracts of the pars 

 intermedia. The source of the opinion that such a probability exists is 

 due to the fact that Lewis, Miller and Mathews (1911) in a careful 

 study of the action of extracts of the various parts of the hypophysis 

 found that extracts of the pars intermedia caused a rise in blood-pressure 

 of the experimental animals analogous to that produced by the usual 

 posterior lobe extracts. These results were confirmed by Biedl (a) ( 1912) . 

 This pressor effect was also obtained by Atwell and Marinus (1918). 

 Herring (/) (1914), however, was unable to obtain any such pressor effect 

 from extracts with Ringer's solution of the isolated pars intermedia as 

 he obtained from his posterior lobe extracts, but did get an initial fall in 

 pressure which lasted but a very short time. Yet he found that his extracts 



