Effects of environmental temperature on hypothermia and neuroendocrine changes induced by soman.
The effects of environmental temperature on body temperature and neuroendocrine parameters were evaluated following a single acute dose (60 micrograms/kg) of soman. Plasma levels of corticosterone, glucose, and free fatty acids, as well as acetylcholinesterase activity in plasma, erythrocytes, and brain were determined over a 96-hr time course in rats maintained at 23-25, 14-16, and 3-5 degrees C. Considerable inhibition of plasma and erythrocyte acetylcholine hydrolysis activity was observed after administration of soman at all three environmental temperatures. The degree of hypothermia in all soman-treated rats in each environment tested was associated with the amount of brain acetylcholinesterase inhibition. In animals maintained at 23-25 and 14-16 degrees C, changes in plasma corticosterone levels were influenced by central acetylcholine hydrolysis. Hyperglycemia was found only in rats with greater than 45% brain inhibition regardless of environmental temperature. However, the plasma concentration of glucose over the 96 hr test period varied in relation to the hydrolysis of acetylcholine in soman-treated rats. Recovery of plasma acetylcholinesterase was more rapid at lower environmental temperatures. A greater inhibition of central acetylcholinesterase was found in soman-treated rats exposed to 3-5 degrees C. Soman may be more toxic at low environmental temperatures.
Maickel
R P
RP
Department of Pharmacology and Toxicology, Purdue University, West Lafayette, Indiana 47906.
Kinney
D R
DR
Ryker
N D
ND
Nichols
M B
MB
D000109:Acetylcholine / Q000097:blood; D000110:Acetylcholinesterase / Q000378:metabolism; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D001831:Body Temperature / Q000187:drug effects; D001921:Brain / Q000378:metabolism; D003345:Corticosterone / Q000097:blood; D004334:Drug Administration Schedule; D004702:Endocrine Glands / Q000187:drug effects*; D004912:Erythrocytes / Q000378:metabolism; D005230:Fatty Acids, Nonesterified / Q000097:blood; D006868:Hydrolysis; D007035:Hypothermia / Q000139:chemically induced*; D007279:Injections, Subcutaneous; D008297:Male; D009420:Nervous System / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains; D012999:Soman / Q000008:administration & dosage / Q000633:toxicity*; D013696:Temperature
D001786:Blood Glucose; D005230:Fatty Acids, Nonesterified; D012999:Soman; D000110:Acetylcholinesterase; D000109:Acetylcholine; D003345:Corticosterone