Action of Morphine on the Epinephrine Output, Blood Sugar Content and Blood Pressure in Dogs

Abstract

Morphine hydrochloride was administered to the dogs, non-anaesthetized, non-fastened, but provided with the lumbar route preparation for collecting the suprarenal vein blood. Before and after morphine the velocity with which epinephrine is secreted from the suprarenal body was estimated. Epinephrine was deternined by means of the rabbit intestine segment method. Blood sugar was simultaneously determined by Hagedorn and Jensen, the mean arterial pressure was also measured.
Morphine hydrochloride was applied subcutaneously in doses varying from 10 to 40 mgrms. per kilo of body weight, intravenously in those of 2 to 8 mgrems. Every application caused an accelerated secretion of epinephrine.
The epinephrine discharge rate increased in every case, its maximum rate being measured as 0.00007-0.00058 mgrm. per kilo per minute, that is about as much as 5 to 25 times the initial rate. The peak was attained about half an hour after the injection in the subcutaneous cases and within 10 minutes in the intravenous. In contrast to the epinephrine output rate the blood sugar concentration reached its acme rather slowly, viz. about one to two hours after the injection, and the modi of application have apparently no significant influence upon the length of time needed for arriving at the acme.
Simultaneous recording of the mean arterial pressure did not yield any close relationship between its variation and that of the epinephrine output rate.