EFFECT OF CHANGES OF AMBIENT TEMPERATURE ON SPONTANEOUS ACTIVITY OFHYPOTHYROID RATS
Abstract
The antithyroid drug, propylthiouracil (PTU), administered to male rats for 4 wk, did not reduce spontaneous running activity in air at 25 C. When room temperature was lowered to 8 C. for 4 days, PTU-treated rats increased their activity level during the first day of exposure but decreased it thereafter. Control rats responded similarly on the first day but continued to increase activity during each subsequent da in cold. In other experiments PTU-treated and control rats were lightly restrained and exposedACUTELY TO AIR AT 5 C. in individual cages. A sensitive transducer converted movement of the cage to electrical impulses which were recorded on a polygraph. Colonic temperature of each rat was recorded simultaneously by a potentiometer. Mean colonic temperature of PTU-treated rats continued to fall throughout the cold exposure and decreased approximately 6 C. in 3 hr. These rats also responded to cold initially with an increase in activity which became maximal when colonic temperature fell 3 to 4 C. This maximal effort occurred too late, however, to preven further fall of colonic temperature. The results suggest that regulation of body temperature in cold air by adjustment of activity level is an important aspect of the total regulatory mechanism and that hypothyroidism alters the relationship between colonic temperature and activity level. ( uthor)
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1961
- Accession Number
- AD0267002
Entities
People
- Melvin J. Fregly
Organizations
- United States Air Force School of Aerospace Medicine