Accession Number:

AD0731591

Title:

Catecholamine and Metabolite Excretion in Cold-Stressed Immunosympathectomized Rats,

Descriptive Note:

Corporate Author:

TORONTO UNIV (ONTARIO) DEPT OF PHARMACOLOGY

Personal Author(s):

Report Date:

1970-10-26

Pagination or Media Count:

5.0

Abstract:

Sixteen immunosympathectomized IS rats were kept at 28C for several days and then transferred to 4C for 4 weeks. Sixteen IS rats remained at 28C throughout the study. Urine was collected at both temperatures and analyzed for epinephrine, norepinephrine, and their major metabolites. Cold exposure increased norepinephrine and normetanephrine excretion, which remained elevated for the duration of the study. It is concluded that IS does not prevent an increase in norepinephrine secretion in the cold. However, when compared with untreated littermates, the IS rats excreted slightly less norepinephrine and normetanephrine during the first 3 weeks at 4C. After 4 weeks at 4C no difference in norepinephrine and normetanephrine between the two groups was seen. The major difference between the IS and control rats was in 3-methoxy-4-hydroxyphenylethylene glycol MHPG excretion. Upon exposure to 4C MHPG was lower in the IS rats. It is postulated that a decreased sympathetic reserve in these animals caused a higher percentage of norepinephrine synthesized to be secreted as such, causing the lower MHPG excretion. Author

Subject Categories:

  • Stress Physiology

Distribution Statement:

APPROVED FOR PUBLIC RELEASE