Splanchnic stimulation, adrenin and shortening of coagulation time

Cannon's Bodily Changes in Pain, Hunger, Fear and Rage (1915) presents records of these experiments. One shows the shortening of coagulation after stimulation of the left splanchnic nerve in a cat whose brain had been pithed.¹ Another series began on Nov. 6 with a cat anesthetized with urethane, whose brain was pithed later the same afternoon.⁴ A further cat was kept under uniform ether anesthesia with artificial respiration, and its left splanchnic nerve was stimulated in the thorax. Its clotting times were measured before and after.² Cannon's records show shortening of clotting time under urethane and in pithed cats.

Cannon reported that coagulation time was reduced to less than half its former value in the foregoing instances. He added that the reduction was not always so pronounced.² The effect also varied in timing. A primary delay before the shortening appeared was not commonly present, and some records showed a prompt effect.³ Cannon noted that one record, though lower, showed oscillations not unlike those that follow injection of adrenin.³

Bayliss (1915) described the splanchnic nerves as the sympathetic supply to the intestine and as inhibitory. Exciting them stopped rhythmic contractions and abolished tone.⁵ Crile's bibliography (1926) lists a paper from 1912 on the control of the suprarenal glands by the splanchnic nerves.⁶ It also lists Hoskins and Gunning (1917) on the effects of adrenin on the distribution of the blood.⁷ Loeb (1916) uses the term coagulation time in a different sense. He suggested that high temperature coefficients at the upper limits of life might express the coagulation of certain proteins.⁸ That is not the clotting of blood.