RELATION SUPRARENAL GLANDS TO CIRCULATION 219 



Furthermore, constriction of the intestine was often seen when arterial 

 pressure was elevated above the normal. 



The amount of epinephrin required to bring about dilatation of the 

 intestine was also found to be quite variable. The range of dosage was 

 from 0.04 to 0.4 c.c. of 1 :1,000,000 solution per kilogram. The latent 

 period of the dilatation was longer than that of the constriction, and the 

 constrictor effect seemed to be superimposed upon the dilator. As the dose 

 was increased the resulting constriction became more and more marked 

 and prolonged. When, however, the dosage passed the threshold for the 

 constrictor effect, the dilatation phase was shortened by one-fourth to two- 



. 



Fig. 10. Graph showing preliminary contraction followed by prolonged dilatation 

 of the intestine of a dog following injection of 0.2 c.c. 1:10,000 solution epinephrin. 

 (Reduced one-third.) (After Hartman and McPhedran, Am. J. Physiol.) 



thirds of its former length. As in case of the constrictor effect, it was not 

 possible to correlate the dilator effect with changes in arterial blood- 

 pressure. 



When the sympathetic ganglia were removed or the splanchnic nerves 

 were cut, the dilator effect of epinephrin was entirely done away with, 

 only constriction then being elicitable. 



Similar investigations were reported by Hoskins and Gunning (1917). 

 These investigators, in addition to volume studies, determined the venous 

 outflow. Their experiments were made in all cases upon dogs. The 

 results are summarized in the accompanying table. The most prominent 

 features of their findings as a whole were augmentation of the intestinal 

 volume and of outflow from the opened veins. Often, however, the dilata- 

 tion phase was preceded by a more or less pronounced contraction and in 

 some instances contractions only were obtained. In case of the venous 

 outflow the results were somewhat more consistent, augmentation always 

 being noted, but this was not infrequently preceded by a decrease during 



