[Pathological changes of major organs after rats inhaled methyl ethyl ketone peroxide aerosol].
OBJECTIVE
To investigate the pathological changes of major organs in rats that have inhaled methyl ethyl ketone peroxide (MEKP) aerosol and to provide clues to the oxidative damage mechanism of MEKP.


METHODS
A total of 100 Sprague-Dawley rats (male-to-female ratio = 1:1) were randomly and equally divided into blank control group, solvent control group, and 50, 500, and 1000 mg/m(3) MEKP exposure groups to inhale clean air, solvent aerosol, or MEKP for 6 h per day, 5 d per week, for 13 weeks. A rat model of subchronic MEKP exposure was established. The clinical manifestations during exposure were recorded. The organ coefficients of the kidney, thymus, and testis were calculated. The histopathological changes of the lung, liver, and testis were observed by HE staining.


RESULTS
The male rats in 1000 mg/m(3) MEKP exposure group had significantly lower organ coefficients of the kidney and testis than those in blank control group, solvent control group, and 50 and 500 mg/m(3) MEKP exposure groups (P < 0.05). The rats in 1000 mg/m(3) MEKP exposure group had a significantly lower organ coefficient of the thymus than those in blank control group and solvent control group (P < 0.05). Some rats in 500 and 1000 mg/m3 MEKP exposure groups had significant damage to the lung, liver, and testis, which demonstrated a worsening trend as the dose increased. Pulmonary hyperinflation, hyperemia, bleeding, interstitial pneumonia, and even lung abscess were seen in the damaged lung. Nuclear enrichment, hepatocyte steatosis, and mild cellular edema in the portal area were seen in the damaged liver. Variable degeneration, necrosis, and dysplasia of spermatogenic cells and significant decrease in sperms in spermatogenic cells were seen in the damaged testis. The female rats in blank control group, solvent control group, and 50, 500, and 1000 mg/m(3) MEKP exposure groups showed no pathological changes in the ovary.


CONCLUSIONS
Inhalation of MEKP aerosol can cause oxidative damage to the liver, lung, kidney, thymus, and testis in rats, particularly to the testis in male rats.
Tianjin Medical University, Centers for Disease Control and Prevention of Tianjin, Tianjin 300011, China.
Ling
L
Liu
Yan-rang
YR
Wang
Feng-shan
FS
Wang
Jing
J
Liu
D000818:Animals; D002074:Butanones / Q000008:administration & dosage / Q000633:toxicity*; D005260:Female; D019570:Inhalation Exposure; D007668:Kidney / Q000187:drug effects / Q000473:pathology; D008099:Liver / Q000187:drug effects / Q000473:pathology; D008168:Lung / Q000187:drug effects / Q000473:pathology; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013737:Testis / Q000187:drug effects / Q000473:pathology; D013950:Thymus Gland / Q000187:drug effects / Q000473:pathology
D002074:Butanones; C011007:methyl ethyl ketone peroxide