Whole-body autoradiographic disposition, elimination and placental transport of [14C]tri-o-cresyl phosphate in mice.
Tri-o-cresyl phosphate (TOCP) is used commercially as a plasticizer and flame retardant. The disposition, metabolism, elimination and transplacental uptake of [phenyl-U-14C]TOCP and/or its metabolites, in pregnant and non-pregnant mice, were examined. Pregnant (18th-day gestation) and non-pregnant, ICR mice were given an i.v. dose of [14C]TOCP (557 microCi kg-1; Specified activity 4.83 microCi mumol-1). At various time intervals (1, 24, 48 and 72 h) the animals were processed for whole-body autoradiography (WBA). Over 72 h the non-pregnant mice excreted 55% of the 14C in the urine and 9% in the feces, while excretion in the urine and feces by the pregnant mice was 50% and 9% of the total dose, respectively. The WBA and its computer-assisted image analysis indicated extensive distribution of the 14C label originally dosed as [14C]TOCP in pregnant mice and their fetuses. The retention of radioactivity in organs such as lung, spleen, gall-bladder and liver of mother and its fetuses suggest that these are the target sites of TOCP toxicity. The distribution in non-pregnant and pregnant mice and in the fetal tissues followed a similar pattern in uptake and retention until 72 h. Brain and spinal cord had the least amount of [14C]TOCP. This finding may support reports that explain the insensitivity of the mice towards organophosphate-induced delayed neurotoxicity (OPIDN) of TOCP.
Department of Pathology, University of Texas Medical Branch, Galveston 77555-0605.
A E
AE
Ahmed
S
S
Jacob
S
S
Soliman
N
N
Ahmed
K
K
Osman
J P
JP
Loh
N
N
Romero
D000818:Animals; D001345:Autoradiography; D005260:Female; D005333:Fetus / Q000000981:diagnostic imaging / Q000378:metabolism*; D005704:Gallbladder / Q000378:metabolism; D007091:Image Processing, Computer-Assisted; D007421:Intestine, Small / Q000000981:diagnostic imaging / Q000378:metabolism; D008099:Liver / Q000000981:diagnostic imaging / Q000378:metabolism; D051379:Mice; D008813:Mice, Inbred ICR; D011247:Pregnancy; D011859:Radiography; D013997:Time Factors; D014018:Tissue Distribution; D014317:Tritolyl Phosphates / Q000008:administration & dosage / Q000493:pharmacokinetics* / Q000652:urine
D014317:Tritolyl Phosphates; C025541:tri-o-cresyl phosphate