Carbamate-induced performance and thermoregulatory decrements restored with diazepam and atropine.
When rats (500 g, male) are exercised on a treadmill, pretreatment with the carbamate physostigmine reduces endurance capacity (run time, RT) and increases the rate of rise of core temperature (heating rate, HR). Because physostigmine is a potential nerve agent pretreatment drug, our objective was to determine whether pharmacological intervention could reverse these decrements in performance and thermoregulation. The following drugs were administered separately via tail vein: vehicle-control (C), atropine (200 micrograms.kg-1, A), diazepam (500 micrograms.kg-1, D), and physostigmine (200 micrograms.kg-1, PH). After drug administration, rats were run (11 m.min-1, 6 degrees elevation, Ta = 26 degrees C) to exhaustion. PH administration resulted in reduced RT (41 min PH vs. 53 min C, p less than 0.05) with greater HR (0.090 degrees C.min-1 PH vs. 0.057 degrees C.min-1 C, p less than 0.01) than control rats. However, when A and D were also given to PH treated rats, the RT and HR were restored to control levels. Further, A and D without PH improved RT and HR (82 min, 0.047 degrees C.min-1) over control levels. Serial administration of an anticholinergic, an anticonvulsant, and an anticholinesterase resulted in no significant change in performance from control levels.
U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts 01760-5007.
C B
CB
Matthew
R W
RW
Hubbard
R P
RP
Francesconi
G J
GJ
Thomas
D000818:Animals; D001285:Atropine / Q000494:pharmacology; D001833:Body Temperature Regulation / Q000187:drug effects*; D003975:Diazepam / Q000494:pharmacology; D008297:Male; D010807:Physical Endurance / Q000187:drug effects*; D010830:Physostigmine / Q000009:adverse effects*; D051381:Rats; D011919:Rats, Inbred Strains
D001285:Atropine; D010830:Physostigmine; D003975:Diazepam