Atropine, diazepam, and physostigmine: Thermoregulatory effects in the heat-stressed rat

Journal Article · Sat Dec 31 23:00:00 EST 1988 · Life Sciences; (USA)

DOI:https://doi.org/10.1016/0024-3205(89)90404-9· OSTI ID:5349463

Matthew, C B; Hubbard, R W; Francesconi, R P ^[1]

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1. Army Research Institute of Environmental Medicine, Natick, MA (USA)

The authors have previously reported that administration of atropine (A) to unrestrained, sedentary, heat-stressed rats resulted in a dose dependent increase in heating rate. Additionally, we have demonstrated that the decrements in treadmill endurance and increments in heating rate of physostigmine (PH)-treated running rats can both be restored to control levels by pretreating the animals with A and diazepam (D). Our objective in the present work was to determine if the administration of D+PH to A-treated unrestrained, sedentary, heat-stressed rats could improve their thermal tolerance. The following drugs were administered singly via lateral tail vein: vehicle-control (C), A (200 ug/kg), D (500 ug/kg), and PH (200 ug/kg). After drug administration, the rats were heat-stressed until a core temperature of 42.6{degree}C was attained when they were removed to a 26{degree}C chamber. The heating rates ({degree}C/min) and tolerance times (min) of the respective groups were: C- 0.02, 235; A- 0.08, 58; A+D- 0.06, 94; and A+D+PH- 0.04, 143. Administration of D with A significantly decreased heating rate, and D+PH more than doubled the thermal tolerance of A-treated rats. Thus, the combination of A+D+PH not only restores PH- induced performance and thermoregulatory decrements of rats exercised in a moderate environment, but also reduces A- induced heat intolerance.

• OSTI ID: 5349463
• Journal Information: Life Sciences; (USA), Journal Name: Life Sciences; (USA) Vol. 44:25; ISSN 0024-3205; ISSN LIFSA
• Country of Publication: United States
• Language: English

Related Subjects

560200* -- Thermal Effects
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ALKALOIDS
ANIMALS
ATROPINE
AUTONOMIC NERVOUS SYSTEM AGENTS
BIOLOGICAL EFFECTS
BIOLOGICAL STRESS
CONTROL
DRUGS
ENERGY
HEAT
MAMMALS
ORGANIC COMPOUNDS
PARASYMPATHOLYTICS
PARASYMPATHOMIMETICS
RATS
RODENTS
TEMPERATURE CONTROL
TEMPERATURE EFFECTS
THERMOREGULATION
TOLERANCE
VERTEBRATES