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.
Matthew
C B
CB
U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts 01760-5007.
Hubbard
R W
RW
Francesconi
R P
RP
Thomas
G J
GJ
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