Normal Survival Period Following Bilateral Epinephrectomy in the Cat.

Abstract

Marked discrepancies in regard to the normal survival period in cats, following bilateral adrenal extirpation, are apparent throughout the literature dealing with the adrenal cortex. Zwemer 1 states the average survival period for a series of 43 cats to be 53 hours with 26 and 111 hours as the extremes. Swingle 2 finds the average survival period for bilaterally epinephrectomized cats to be about 60 hours. Houssay and Lewis 3 found that animals from which the last vestige of cortical tissue had been removed survived but from 24 to 26 hours. Hartman, 4 in seeking an active cortical extract, considered 90 hours as a marked prolongation of the life of bilaterally operated cats. The above references will serve as evidence that no definite criterion has as yet been established in work of this nature.

In a series of 31 animals the author has found the average survival period to be 115 hours, and concludes that the normal life-span of untreated bilaterally epinephrectomized cats must be placed slightly in excess of 100 hours. These findings have been completely corroborated by the recent work of other investigators.

Hartman 5 has placed the average survival period at from 5 to 6 days. Marine and Bauman 6 also agree that the life-span should be placed at somewhat in excess of 100 hours (5.3 days). Professor Swingle, in recent communications to the author, states that he would place this period in excess of 100 hours. Zwemer, in a recent conference with the writer, has stated that he would at present place the life-span of control animals at approximately 100 hours.

The author is inclined to attribute the comparatively short survival periods obtained by various workers to imperfections in operative technique, excessive visceral manipulation during operation, or to excessive handling and excitation.