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5333855 
Journal Article 
Evaluation of Technical HCH Residues in Differentiating Rat Intestinal Epithelial Cells 
Shukla, S; Upreti, RK; Raizada, RB; Srivastava, MK; Kidwai, AM 
1996 
Yes 
Bulletin of Environmental Contamination and Toxicology
ISSN: 0007-4861
EISSN: 1432-0800 
56 
4 
617-621 
English 
8645919 
The accumulation of technical hexachlorocyclohexane (58899) (HCH) residues in intestinal epithelial cells of rats was studied. Male albino-rats were administered 0 or 50mg/kg HCH orally. They were killed 0, 24, 48, 72, or 120 hours (hr) later and the small intestines were removed. The epithelial cells were isolated and dissociated into four fractions on the basis of their protein content and alkaline-phosphatase activity: the upper villi (UV), middle villi (MV), lower villi (LV), and crypt. The fractions contained approximately 20, 30, 30, and 20% of the total intestinal protein content of the preparations, respectively. The cell preparations were extracted with n-hexane. After cleanup by mixed phase chromatography, the extracts were analyzed for HCH by gas liquid chromatography. The isomeric composition of the HCH residues was also determined. Maximum accumulation of total HCH residues detected at the 24hr sampling point was seen in crypt cells, followed by LV, MV, and UV cells. The concentrations of the residues were decreased in UV, MV, and LV cells at 48hr. After 72hr, high levels of total HCH residues were seen in MV and LV cells. The predominant HCH isomer found in all cell fractions was beta-hexachlorocyclohexane (319857). Somewhat smaller amounts of alpha-hexachlorocyclohexane (319846) were found. Only very small amounts of gamma-hexachlorocyclohexane (58899) were found. The authors conclude that the changes in concentration of the total HCH residues found in the various intestinal cell fractions over time reflect their being metabolized and the upward migration of immature crypt cells. The low levels of gamma-hexachlorocyclohexane, the isomer with the greatest insecticidal activity relative to the other isomers, probably reflect its rapid metabolism and elimination from the intestine.