130 THE ROYAL SOCIETY OF CANADA 



V. Anrep/who used dogs for his experiments, reports that stimu- 

 lation of the splanchnic nerves causes a rise of blood-pressure which 

 occurs in two phases. The second phase is accompanied by con- 

 striction of peripheral blood-vessels (even after denervation) and by 

 acceleration and increased tone and augmentation of the heart (also after 

 denervation). The secondary rise, and all the concomitant phenomena, 

 are due to the discharge of adrenin into the circulation and are absent 

 after extirpation of both adrenal bodies. Every rise of blood-pressure, 

 brought about by the agency of the nervous system, thus involves 

 the co-operation of the chemical mechanism represented by the adrenal 

 bodies. The contraction of blood-vessels in denervated limbs under 

 splanchnic stimulation which was regarded by Bayliss as a local 

 reaction to increased pressure, is interpreted by V. Anrep^ as due 

 to the action of adrenin. The rise of blood-pressure during asphyxia 

 is also looked upon by this author as being partly due to constriction 

 of somatic vessels as a result of the action of adrenin upon them. 



Gley and Quinquaud^ * ^ have recently thrown doubt upon the 

 validity of these experiments. They think that ligature of the vessels 

 of the adrenal bodies or extirpation of the organs in the dog involves 

 damage to some of the splanchnic vaso-constrictor fibres and that this 

 accounts for the alteration in splanchnic blood-pressure curve. In 

 the cat and the rabbit such alteration does not occur. In these 

 animals the nerves are not so intimately connected with the adrenal 

 bodies. 



These criticisms of Gley have prompted us to a reinvestigation 

 of the subject. Our experiments have been carried out upon dogs, 

 cats, and rabbits. At the outset it was found that the condition 

 under which the experiment was performed made a very considerable 

 difference to the character of the curve obtained by splanchnic stimu- 

 lation. There may also be differences characteristic of the different 

 species and of different conditions of the animal. V. Anrep never 

 seems to have obtained in his dogs under normal conditions a form 

 of curve which we now look upon as the normal, viz., a sharp rise 

 (sometimes in two phases) followed by a marked dip nearly down 

 to the base line and succeeded by a rise which lasts as long as stimula- 

 tion is continued. This occurs in dogs under ether with both vagi 

 cut and the dip is more pronounced when the operation is conducted 

 from the abdominal cavity and the intestines are freely exposed. 



IV. Anrep., Journ. Physiol., 1912-13, Vol. XLV., p. 307. 



2V. Anrep, Ibid 1912-13, Vol. XLV, p. 318. 



^Gley, E. and Quinguand, A., Comptes rendus, 1913, t. 157, p. 66. 



^Gley, E., and Quinquand, A., Comptes rendus, 1916, t. 162, p. 86. 



^Gley, E., and Quinquand, A., C.R., Soc. de Biol., 1917, t. LXXX, p. 15. 



