Maternal nutrients

Although few studies (M5) have been made on the physiological role of placental alkaline phosphatase, it is reasonable to assume that it is concerned with absorption and active transport of maternal nutrients destined for the maintenance of fetal life. 

Dolinoy DC, Huang D, Jirtle RL (2007) Maternal nutrient supplementation counteracts bisphenol A-induced DNA hypomethylation in early development. Proc Natl Acad Sci USA 104(32) 13056-13061... 

Nutrient supply to the foetus depends on maternal nutrient supply. Therefore, imbalanced nutrition of the gestating sow by energy and/or protein intake may result in lUGR. 

Primarily to elucidate transporter localization and function, vesicles enriched in trophoblast apical or basolateral membranes have frequently been utilized. To give a few instances, they have been used to investigate P-gp-mediated transport, mechanisms of transport of cationic compounds, drug interactions with nutrient transport, and differences in amino acid transport in pathological conditions of the placenta [36, 40-42], Briefly, for preparation of microvillus membrane vesicles the cord, amniochorion and decidua are removed from placenta, and the tissue cut on the maternal side. The mince is stirred to loosen... 

Gases, nutrients, hormones, electrolytes, antibodies and waste products are transported across the placenta. Many drugs and infectious agents can also cross the placenta. Maternal transfer of steroid hormones across the placenta is limited. When natural or synthetic steroid hormones do cross the placenta, developmental toxicity can result. Furthermore, hormones produced by the fetal placenta also play an important role in parturition. 

The placenta is an extremely permeable membrane which separates the fetal blood supply from the maternal blood supply. Normally it allows for the exhange of gases, nutrients and metabolites between mother and child. It... 

Bone et al.20 originally showed that MP was as highly variable in the infant retina as it is in the adult retina. Z is the dominant carotenoid in the center of the adult retina and L predominates in the periphery (thus, in vivo measures of MP account mostly for zeaxanthin concentration). This ratio appears to be reversed in the infant retina, where L dominates in the center (at this point, of course, the macula is quite immature and similar to the periphery). Although all of the factors responsible for the wide variation in infant MP have not been studied, dietary intake of L and Z is still clearly necessary. Whereas MP can be manipulated in the adult via intake of xanthophyll-rich foods, the obvious concern with infants is that food options are limited to breast milk or manufactured infant formulas. Breast milk contains at least 300 defined nutrients, whereas most infant formulas contain approximately 60-70 defined nutrients76 Currently, infant formula does not contain L and Z in other than trace amounts,76 and many formulas are completely devoid of L. In contrast, breast milk contains L and Z in concentrations that are approximately proportional to maternal intake of these carotenoids.77 These observations are important since many infants are exclusively formula fed. Johnson et al.21 showed that breast-fed infants and formula-fed infants had the same levels of plasma L and Z at birth. After 1 month, however, plasma L and Z significantly increased for the breast-fed infants and decreased in the formula-fed infants. This implies that retinal levels in formula-fed infants are also low. 

Dr. Meskin s major areas of research interest include (1) hepatic drug metabolism and the effects of nutritional factors on drug metabolism and clearance (2) nutrient-drug interactions (3) the role of bioactive non-nutrients (phytochemicals, herbs, botanicals, and nutritional supplements) in disease prevention and health promotion (4) fetal pharmacology and fetal, maternal, and pediatric nutrition (5) nutrition education and (6) the development of educational programs for improving science literacy and combating health fraud. 

Two umbilical arteries from the foetus carry blood to the placenta and a single umbilical vein returns blood from the placenta back to the foetus. The functions of the placenta in pregnancy are to supply oxygen and nutrients from the maternal circulation to the foetus and to remove waste materials, such as urea and carbon dioxide, from foetal blood. 

The placenta develops from a portion of the zygote and thus has the same genetic endowment as the developing fetus (78). The embryonic/fetal component consists of trophoblastic-derived chorionic villi/ which invade the maternal endometrium and are exposed directly to maternal blood in lake-like structures called lacunae. These villi create the large surface area necessary for maternal-fetal transfer in what becomes the intervillous space of the placenta. Here the maternal blood pressure supplies pulsatile blood flow in jetlike streams from the spiral arteries of the endometriunX/ to bathe the chorionic villi and allow for transfer of gaseS/ nutrientS/ and metabolic products. Biologically/ the human placenta is classified as a hemochorial placenta because maternal blood is in direct contact with the fetal chorionic membrane. It is this membrane that determines what is transferred to the fetus. 

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