Polychlorinated Biphenyl Uptake and Transport by Lymph and Plasma Components

Abstract

The uptake and vascular transport of ingested Aroclor 1242, an isomeric mixture of polychlorinated biphenyls (PCB), was investigated in experimental animals. High concentrations of ingested PCB were found in the chylomicron fraction of thoracic duct lymph. When the lymph flow was exteriorized PCB were not subsequently found in the vascular circulation. When lymph was not exteriorized plasma PCB concentrations reached maximal levels 6 hr after ingestion. Less than 1% of total plasma PCB was detected in cellular fractions of blood over a 10-hr period following ingestion. Chylomicrons contained 3 1% of total plasma PCB 30 min after ingestion, decreasing to less than 6% at 4 hr. A maximum of 10% of plasma PCB at 116

Enhancement of oral moxidectin bioavailability in rabbits by lipid co-administration

“…The importance of the physiological process of lipid digestion in stimulating lymphatic transport of lipophilic drugs has been reviewed (Porter and Charman 1997) and is especially important for a number of highly lipophilic xenobiotics, such as DDT and related analogues (Sieber 1976), naftifine (Grimus and Schuster 1984), probucol (Palin and Wilson 1984), polychlorinated biphenyls (Busbee et al 1985) and halofantrine (Porter et al 1996). The presence of food has been shown to greatly increase the lymphatic transport of halofantrine: its lymphatic absorption was 54% of the administered dose in the postprandial dog compared with 1.3% in the fasted animal (Khoo et al 2001).…”

Enantioselective disposition of PCB 136 (2,2′,3,3′,6,6′‐hexachlorobiphenyl) in C57BL/6 mice after oral and intraperitoneal administration

“…49 Therefore, similar to other species, [17][18][19] the enantiomeric enrichment of (þ)-PCB 136 in this study could be the result of the more rapid metabolism of (À)-PCB 136 by cytochrome P-450s in the liver. Alternatively, the higher EF values in the oral treatment groups may also be due to administration route-specific differences in the disposition of PCB 136, for example circulation of PCB 136 through the lymphatic system following oral administration, [53][54][55] or caused by a currently unknown transporter for PCBs. 56 The EFs from female animals sacrificed 3 and 6 days after exposure to PCB 136 showed no increase, or only a slight increase, of the EF values in a few tissues (i.e., adipose tissue, spleen, blood, and brain).…”

Chiral polychlorinated biphenyls: absorption, metabolism and excretion—a review

“…To enter the systemic circulation, PCBs must diffuse from the bulk intestinal content to the intestinal wall (for a review of intestinal absorption and biomagnification models see (Kelly et al 2004)). Since PCBs enter the systemic circulation of several species, including ring doves (Drouillard and Norstrom 2000), dogs (Busbee et al 1985) and humans (Kuwabara et al 1979), at rates similar to those observed for dietary lipids, PCBs are thought to move to the intestinal wall dissolved in mixed micelles (i.e., micelles containing bile salts, lipids and lipid digestive products) (Dulfer et al 1998, Dulfer et al 1996, Oomen et al 2001) prior to entering the enterocyte by passive diffusion (Dulfer et al 1998). As a result, oral absorption of PCBs is highly efficient; however, higher chlorinated congeners are less efficiently absorbed than lower chlorinated ones in most species, including fish (Gobas et al 1988), ring doves (Drouillard and Norstrom 2000), rats (Matthews and Tuey 1980, Tanabe S. 1981), cows (McLachlan 1993) and humans (Jödicke et al 1992), probably due to their lower solubility in the interior of mixed micelles (Dulfer and Govers 1995).…”