Adipose tissue aldehydes

Exposure Levels in Humans. Metabolism of endrin in humans is relatively rapid compared with other organochlorine pesticides. Thus, levels in human blood and tissue may not be reliable estimates of exposure except after very high occupational exposures or acute poisonings (Runhaar et al. 1985). Endrin was not found in adipose tissue samples of the general U.S. population (Stanley 1986), or in adipose breast tissue from breast cancer patients in the United States (Djordjevic et al. 1994). Endrin has been detected in the milk of lactating women (Alawi et al. 1992 Bordet et al. 1993 Dewailly et al. 1993), but no data from the United States could be located. Data on the concentrations of endrin in breast milk from U.S. women would be useful. No information was found on levels of endrin, endrin aldehyde, or endrin ketone in blood and other tissues of people near hazardous waste sites. This information is necessary for assessing the need to conduct health studies on these populations. 

Methoxyethanol is rapidly absorbed through the skin and lungs into the blood. Its water solubility favors distribution to all body tissues except adipose tissue. Metabolism occurs via two pathways. Methoxyethanol is a substrate for alcohol dehydrogenase, and the resultant methoxyacetaldehyde is metabolized to methoxyacetic acid by aldehyde dehydrogenase. In rats, pretreatment with phenobarbitol decreased formation of methoxyacetaldehyde but accelerated formation of methoxyacetate in liver cytosolic fractions. A minor pathway involves demethylation by undefined enzymes to ethylene glycol and CO2. 

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