Accession Number:

ADA273291

Title:

Thermoregulatory Effects of Atropine in the Cold Using a Hypotrichotic Rat Model

Descriptive Note:

Final rept.

Corporate Author:

ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA

Report Date:

1993-11-01

Pagination or Media Count:

13.0

Abstract:

The objectives of this research were to determine the effects of atropine on thermoregulation and peripheral vasodilation in the cold. A conscious, confined but unrestrained, hypotrichotic Wistar-Furth, fuzzy rat model was used. Electromyography EMG was utilized to assess the shivering response of the trapezius muscle. An EMG frequency band between 3 Hz and 1 kHz was rectified, then integrated for determination of a shivering index. Infrared thermography was used to monitor dorsal body skin temperature as an indirect assessment of cutaneous blood flow. Rats were injected in the lumbar musculature with either 1 mgkg atropine A or an equivalent volume 0.15 ml of saline S 30 minutes after exposure to either 25 deg C, 18 deg C or 12 deg C. Data were then collected for an additional 90 minutes. There were no significant between group A vs. S, p0.05 differences in shivering, rectal temperature T sub re, skin temperature or tail temperature at 25 deg C n6group, 18 deg C n7 group, or 12 deg C n12group . Modest within group decrements in T sub re, occurred between 10 and 90 min following A injection at 18 deg C and 12 deg C. A transient decline in shivering occurred following atropine administration at 12 deg C, but baseline levels were reached by 20 min post-injection. We concluded that intramuscular injection of A caused a small decrease in T sub re in a cold- stressed hypotrichotic rat model. However, this decrease could not be entirely explained by shivering inhibition nor by cutaneous vasodilation.

Subject Categories:

  • Anatomy and Physiology
  • Pharmacology

Distribution Statement:

APPROVED FOR PUBLIC RELEASE