Neurotoxicological Effects Associated with Short-Term Exposure of Sprague–Dawley Rats to Hydrogen Sulfide

• Published in: Neurotoxicology (Park Forest South) Vol. 22; no. 3; pp. 375 - 385
• Main Authors: Struve, Melanie F, Brisbois, Jennifer N, Arden James, R, Marshall, Marianne W, Dorman, David C
• Format: Journal Article
• Language: English
• Published: Orlando, FL Elsevier B.V 01-06-2001; Elsevier
• Subjects: Administration, Inhalation; Air Pollutants - toxicity; Animals; Atmosphere Exposure Chambers; Behavior; Biological and medical sciences; Body Temperature - drug effects; Brain - drug effects; Brain - metabolism; Catecholamines - metabolism; Chemical and industrial products toxicology. Toxic occupational diseases; Conditioning, Operant - drug effects; Gas, fumes; Hydrogen sulfide; Hydrogen Sulfide - administration & dosage; Hydrogen Sulfide - toxicity; Inhalation; Male; Maze Learning - drug effects; Medical sciences; Motor Activity - drug effects; Rat; Rats; Rats, Sprague-Dawley; Toxicology; Water maze; Hydrogen sulfide; Behavior; Rat; Water maze; Inhalation; Short term; Nervous system diseases; Toxic gas; Hydrogen Sulfides; Toxicity; Memory; Rodentia; Catecholamine; Learning; Multiple dose; Vertebrata; Mammalia; Animal; Brain (vertebrata)
• ISSN: 0161-813X; 1872-9711
• DOI: 10.1016/S0161-813X(01)00021-3

Although hydrogen sulfide (H
2S) is a known neurotoxic hazard, only a limited number of experimental animal studies have examined its neurochemical or behavioral effects. Our aim was to determine if short-term inhalation exposure of rats to H
2S would result in altered brain catecholamine levels or impaired learning and memory. Three groups of adult male CD rats were tested; two groups were exposed by nose-only inhalation (0, 30, 80, 200, or 400
ppm H
2S) and one group was exposed by whole-body inhalation (0, 10, 30, or 80
ppm H
2S) for 3
h per day for five consecutive days. The first group (n
=
10 rats per concentration) was tested immediately following each daily nose-only H
2S exposure for spatial learning with a Morris water maze. Core body temperatures were also monitored in these animals during and after the last H
2S exposure. The second group of rats (n
=
10 rats per concentration) was tested for spontaneous motor activity immediately following the fifth exposure. These rats were then euthanized and striatal, hippocampal, and hindbrain catecholamine levels determined. A third group of rats (n
=
5–7 rats per concentration) was pretrained on a multiple fixed-interval (FI) schedule and exposed whole-body. Daily performance on the FI schedule was compared for the week pre-exposure, for the exposure week immediately following daily exposures, and for the week postexposure. We observed significant reductions in motor activity, water maze performance, and body temperature following exposure only to high concentrations (≥80
ppm) of H
2S. Exposure to H
2S did not affect regional brain catecholamine concentrations or performance on the FI schedule. Additional studies using other measures of behavior and longer-term exposure to H
2S may be required to more definitively address conditions under which H
2S exposure results in behavioral toxicity.