Manganese uptake

Moffett, J.W. (1994) A ratiotracer study of cerium and manganese uptake onto suspended particles in Chesapeake Bay. Geochim. Cosmochim. Acta, 58, 695-703. 

Mucci A. (1988) Manganese uptake during calcite precipitation from seawater Conditions leading to the formation of a pseudokutnahorite. Geochim. Cosmochim. Acta 52, 1859-1868. 

M. Aschner, K. E. Vrana, W. Zheng, Manganese uptake and distribution in the central nervous system (CNS), Neurotoxicology, 20 (1999), 173-180. 

Manganese has been found to be an essential nutrient for the human as well as for many other living organisms however, in excessive amounts, it is also a toxic material (1-6). Deficiency symptoms for manganese in several species have been created and manganese metabolic roles have, at least in part, been defined (5,7-15). So called "normal" manganese concentrations in blood have been established (1,10,16). Kinetics of manganese uptake and metabolism by... 

Table 1. Manganese uptake from milks and formulas in d 14 rat pups1...

It is possible that the effect of purified cellulose on manganese differs from that of cellulose provided from whole foods. Ranhotra et al. (46) found that products naturally high in cellulose such as wheat bran, soy flour, and vegetable flour reduced availability of iron, while purified cellulose had no effect. Further studies with cellulose in both purified and natural form will be necessary to determine if the reduction in manganese uptake produced by cellulose could lead to adverse nutritional consequences. 

Experiments In this laboratory examined the effects of small (100 and 300 mg) doses of sodium phytate administered In capsule form on plasma uptake of 50 mg of MnCl. As shown In Figure 5, the 300 mg dose of phytate produced a moderate reduction In manganese response, which was manifested chiefly at hours three and four of the test. The relatively modest effect of phytate on manganese uptake Is somewhat unexpected, since It has been shown that phytic acid may be a more potent Inhibitor of trace element absorption than dietary fibers (35). However, the doses of sodium phytate administered to our subjects were much smaller than the typical daily Intake of 600 to 800 mg (54). Thus we are now Investigating the effects of larger doses of phytate on manganese uptake. 

Manganese in the human is also thought to be absorbed maximally in the duodenum in the II valence state. Therefore, as with manganese uptake by plants, the pH of the upper gastro-intestinal tract might be expected to be of importance in the absorption of manganese by the human. 

Diets high in iron have been shown to suppress manganese absorption, and conversely, iron-poor diets increase manganese uptake (Lonnerdal 1994,1997). Phosphorus (Wedekind et al. 1991) and calcium (Wilgus and Patton 1939) have also been found to decrease manganese uptake. 

Mn(II) pretreatment reduces Cd(II)-induced lethality (Goering and Klaassen 1985). Cadmium has been noted to have an inhibitory effect on manganese uptake (Gruden and Matausic 1989). In addition, manganese appears to be capable of increasing the synthesis of the metal-binding protein metallothionine... 

The EPA Reference Dose (RfD)ZReference Concentration (RfC) workgroup in June 1990 set an RfD for manganese in food of 0.14 mg manganese/kg/day, equivalent to 10 mg/day for a 70-kg man based on chronic manganese uptake (EPA 1993b). The Pood and Nutrition Board of the NRC estimated the adequate and safe intake of manganese for adults at 2-5 mg/day (NAS 1980b). This level was chosen... 

Bell JG, Keen CL, Lonnerdal B. 1989. Higher retention of manganese in suckling than in adult rats is not due to maturational differences in manganese uptake by rat small intestine. J Toxicol Environ Health 26 387-398. 

Keen CL, Bell JG, Lonnerdal B. 1986. The effect of age on manganese uptake and retention from milk and infant formulas in rats. J Nutr 116 395-402. 

Eonnerdal B, Keen CE, Bell JG, et al. 1987. Manganese uptake and retention Experimental animal and human studies. In Kies C, ed. Nutritional Bioavailability of Manganese ACS Symposium Series 354, Washington, DC American Chemical Society, 9-20. 

Golub MS, Han B and Keen CL (1996) Iron and manganese uptake by offspring oflactating mice fed a high aluminum diet. Toxicology 109 111 — 118. 

Rengel Z (2000) Manganese uptake and transport in plants. In Sigel A, Sigel H, eds. Metal Ions in Biological Systems, Vol 37, Manganese and Its Role in Biological Processes, pp. 57-87. Marcel Dekker Inc, New York-Basel. 

Influence of transferrin on manganese uptake in rat brain. J Neurosd Res 59 542—552. 

Aschner, M. Gannon, M. Manganese uptake and efflux in cultured rat astrocytes. /. Neurochem. 1992 58 730-735. 

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