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A Computerized Test Battery to Study Pharmacodynamic Effects on the Central Nervous System of Cholinergic Drugs in Early Phase Drug Development
Published on: February 11, 2019
Cholinergic drug interactions and heat tolerance
C B Matthew1, J F Glenn, W D Bowers
1US Army Research Institute of Environmental Medicine, Natick, MA 01760.
Life Sciences
|January 1, 1994
Summary
Subchronic administration of pyridostigmine bromide (PY) enhances heat tolerance in rats by improving thermoregulation through increased evaporative cooling. This effect, seen with PY and atropine (AT), mimics heat acclimation.
Area of Science:
- Environmental Physiology
- Pharmacology
- Toxicology
Background:
- Cholinergic compounds can have varied effects based on exposure duration.
- Pyridostigmine bromide (PY) is used for organophosphorus poisoning prophylaxis, with atropine (AT) administration influencing its efficacy.
- Atropine (AT) increases core body temperature in heat-exposed subjects.
Purpose of the Study:
- To investigate if atropine's (AT) anticholinergic potency is modified after pyridostigmine bromide (PY) administration.
- To assess the effects of acute versus subchronic PY administration on AT's thermoregulatory effects in heat-stressed rats.
Main Methods:
- Rats received acute or subchronic (2 weeks) intravenous or osmotic pump administration of saline (SAL) or PY.
- Following PY or SAL, rats were treated with SAL or AT (200 ug/kg).
- Rats were then exposed to 41.5°C until core temperature reached 42.6°C, with heat tolerance and weight loss measured.
Main Results:
- Subchronic PY administration significantly improved heat tolerance compared to acute PY.
- Subchronic PY + AT treatment also resulted in greater heat tolerance than acute PY + AT.
- % weight loss, indicating evaporative cooling, was higher in subchronically treated rats.
Conclusions:
- Subchronic administration of anticholinesterase agents like PY can enhance thermoregulation and heat tolerance.
- The observed improvements in heat tolerance resemble physiological changes associated with heat acclimation.
- This suggests potential for subchronic PY to mitigate heat stress effects.
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