Placental transporters

Ganapathy V, Prasad PD, Ganapathy ME, Leibach FH. Placental transporters relevant to drug distribution across the maternal-fetal interface. J Pharmacol Exp Ther 2000 294(2) 413-420. 

Montano, M.M. et al., Sex differences in plasma corticosterone in mouse fetuses are mediated by differential placental transport from the mother and eliminated by maternal adrenalectomy or stress, J. Reprod. Fertil., 99, 283, 1993. 

B.V. Sastry. Techniques to study human placental transport. Adv Drug Deliv Rev. 38 17-39 (1999). 

Failure in the placental transport of essential substrates may be teratogenic and can be caused by certain compounds such as azo dyes. This has, however, only been demonstrated in rodents because of the inverted yolk sac type of placenta such animals have. 

It is not clearly understood to what extent cocaine and/or its metabolites contribute to fetotoxicity. However, the end result appears to be a reduction in uterine blood flow, possibly via blockade of neuronal amine reuptake (see CNS section for more details). Cocaine may also decrease placental transport of amino acids. 

Flessa HC, Kapstrom AB, Glueck HI, Will JJ. Placental transport of heparin. Am J Obstet Gynecol 1965 93(4) 570-3. 

In pregnant women with bronchial asthma, broncho-spasm can be exacerbated during labor, necessitating infusion of aminophylhne. The placental transport of ami-nophylUne and its effects on the fetus and the neonate are poorly understood. A recent report has highlighted the potential problems (29). 

Dancis J, Lehanka J, Levitz M. Placental transport of riboflavin differential rates of uptake at the maternal and fetal surfaces of the perfused human placenta. Am J Obstet Gynecol 1988 158 204-10. 

Vertebrates require much calcium in their food in the USA the recommended daily allowance (RDA) for adult humans is 800 mg, and most other countries have comparable recommendations. During gestation in mammals, calcium must be transported across the placenta into the fetus, in particular during those phases of pregnancy when bone formation is most rapid. Interestingly, there appear to be some parallels between intestinal and placental transport that will be discussed further below. The role of calcium in biominerals is a vast subject that we can treat only superficially in this chapter. 

Distributed parameter, nonlinear, partial differential equations were soloed to describe oxygen transport from maternal to fetal bloody which flows in microscopic channels within the human placenta. Steady-state solutions were obtained to show the effects of variations in several physiologically important parameters. Results reported previously indicate that maternal contractions during labor are accompanied by a partially reduced or a possible total occlusion of maternal blood flow rate in some or all portions of the placenta. Using the mathematical modely an unsteady-state study analyzed the effect of a time-dependent maternal blood flow rate on placental oxygen transport during labor. Parameter studies included severity of contractions and periodicity of flow. The effects of axial diffusion on placental transport under the conditions of reduced maternal blood flow were investigated. 

All different types of experimental systems, from isolated cells to whole tissue perfusion, have been used to. study the placenta (Table 4), Since placenta is anatomically complex and highly polarized in its functions (Ganapathy ei ai, 2000 Cariappa et al 2003), the method to be u,sed has to be carefully considered based on the purpose of the studies. For a complete view of placental transporters (Ganapathy el al, 2000 Cariappa et al., 2003), it may be necessary to use more than one experimental system. Hcikkila and coworkers (2002) demonstrated the integration of a gene construct in placental cells by combining placental pcrfu.sion and explant culture thereafter,... 

However, fairly little is known of the placental transporters. even the best known P-glycoprotein, and pe.sticide transport across the placenta (Abu-Qare et at., 2003). Bain and LeBlanc (1996) studied the effect of 38 pesticides on... 

The compensatory relation between DHA and n-6 DPA levels is clearer in placental transport between mothers and fetuses. Crawford et al. (19) showed gradual increases in DHA level from maternal plasma, fetal cord blood, fetal liver, to fetal brain. They designated the increase as a biomagnification of DHA (19). The same pronunciation of chi for blood, milk, knowledge, wisdom, and soul was used in the ancient... 

Roti E, Gnudi A, Braverman LE, The placental transport, synthesis and metabolism of hormones and drugs which affect thyroid function. Endocrine Rev 4 131 (1983)... 

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