TEMPERATURE STUDIES IN NORMAL AND SUPRARENALECTOMIZED RATS

Abstract

A thermo-couple galvanometer arrangement has been found suitable and accurate for the determination of colonic and vaginal temp. in albino rats. A statistical study of the colonic temp. of adult ?? from 3 different colonies shows a most probable temp. of 38.2[degree] C. with one-half of all determinations lying in the range 37.8[degree] to 38.7[degree] C; the most probable temp. in c?cf is slightly lower. The vaginal temp. closely follows the fluctuations in colonic temp. and is always 1[degree] C. below it. The different stages of estrum show no correlation to the vaginal temp. In both males and females, the temp. distribution is the same for variations in weight, age, colony, season and time of day. The average survival period noted in 164 suprarenalectomies is 15 days; 95% of the rats obtained from 3 different strains died from suprarenal insufficiency. Following complete suprarenalectomy, the colonic temp. remains normal for a relatively long period until 24-72 hrs. before death; in some cases, the fall in temp. in the terminal stages was precipitous in nature. No relationship was found between the semi-comatose condition of a dying animal and any given temp. reading. All control animate showed a normal temp. throughout the experiment. Surgical trauma was a negligible factor in the work. A 10-minute etherization has been used as an experimental method for inducing a fall in body temp. All unoperated and unilaterally adrenalectomized rats showed a normal return of colonic temp. within 2 hrs. Successive daily etherizations of these animals did not influence their ability to recover from an experimental decrease in body temp. The behavior of the colonic temp. of suprarenalectomized rats after a 10-minute etherization may be grouped as follows: 1, normal recovery ; 2, delayed recovery; 3, attempted recovery with subsequent death, and 4, death with no attempt made at recovery. The ability to recover from an experimental fall in body temp. in rats of groups 3 and 4 was definitely impaired. A few results suggest that the longer the period after complete suprarenalectomy, the weaker the resistance of the animal toward an induced fall in body temp. The cortical secretion of the suprarenals is related to the maintenance of body temp. only in so far as its presence is concerned with the normal physiological state of body tissues.