Breast milk storage

High, E. G. and H. G. Day (1951). Effects of different amounts of lutein, squalene, phytol and related substances on the utilization of carotene and vitamin A for storage and growth in the rat. J. Nutr. 43 245-260. Johnson, E. J. et al. (1997). Beta-carotene isomers in human serum, breast milk and buccal mucosa cells after continuous oral doses of -trans and 9-cis beta-carotene. J. Nutr. 127(10) 1993-1999. 

No information is available as to whether w-hexane or its metabolites cross the placenta in humans. Transfer across the placenta has been demonstrated in rats for -hexane and two resulting metabolites, 2-hexanone and 2,5-hexanedione (Bus et al. 1979) no preferential distribution to the fetus was observed for either -hexane or the metabolites. Due to its relatively rapid metabolism, storage of -hexane in body fat does not appear to occur at air concentrations to which humans are exposed thus, there is unlikely to be mobilization of maternally stored -hexane upon pregnancy or lactation. -Hcxanc has been detected in samples of human breast milk (Pellizzari et al. 1982) however, -hexane was not quantified, nor was any attempt made to assess the subjects exposure. A human milk/blood partition coefficient of 2.10 (Fisher et al. 1997) indicates there would be preferential distribution to this compartment if significant absorption occurred however no pharmacokinetic experiments have been... 

Dichlorobenzene is classified as an organochlorine compound and, as such, shares many of the biochemical characteristics of this class of chemicals, which includes high lipid solubility. A few studies have noted that 1,4-dichlorobenzene will preferentially distribute to adipose tissues in relatively high amounts, compared to accumulations in the liver and kidneys (Hawkins et al. 1980 Charbonneau et al. 1989b Klos and Dekant 1994). Loss of maternal body fat may mobilize 1,4-dichlorobenzene from fat storage deposits in exposed mothers. This mobilization could result in increased blood levels and/or excretion of 1,4-dichlorobenzene and its metabolites from the mother, as well as redistribution to other fat deposition sites, such as the high fat content found in breast milk. 

There are three types of defenses against toxic materials internal, antidotal, and external. Three things can happen once a chemical is taken into the body metabolism, storage, and excretion. Internal defenses are the ability of the body to get rid of a toxic material, sometimes referred to as metabolism. The body normally excretes waste materials through the feces or urine. Additionally, women can also excrete through the ova and breast milk. In these instances, the excretions from the mother represent exposure to the offspring. 

The free fatty acids that enter muscle tissue can undergo immediate oxidation to be used as an energy source. Those that enter adipose tissue undergo immediate conversion back to TGs for storage in the adipocyte. These stored TGs are mobilized eventually for use as an energy source. Some are destined for immediate removal, whereas others may remain stored as TXjs for more than one year The falty acids of chylomicrons also are released into lactating breast tissue. Here, they are converted to TGs and secreted in the form of milk lipoproteins. 

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