NEUTRON ACTIVATION ANALYSIS: CLINICAL AND BIOLOGICAL STUDIES OF MANGANESE

From Symposium on Radioactivation Analysis and its Application to the Biological Sciences, Saclay, France, Sept. 1963. The use of neutron activation analysis for studying the metabolism of manganese in the body is discussed. Results of various clinical and biological studies of manganese metabolism are described. Some of the results indicate that pigments (melanin) in general contain high manganese concentrations and might play a role in extrapyramidal diseases. (D.L.C.

Contribuição ao estudo da interrelação flúor-manganês em ratos

Devido a numerosas discrepâncias nos resultados de estudos experimentais relativos à interação flúor-manganês, propusemo-nos a verificar se a adição de manganês 5 água fluoretada (1 ppm), em diferentes proporções fluor-manganês, levaria a uma diferente fixaçao do halogênio. Para tanto, 24 ratos Wistar, recém-desmamados, foram mantidos em dieta padrão de caseína a 27%, recebendo na sua água de consumo: 1) H2O destilada (controle); 2) 1,0 ppm de flúor: 3) 1,0 ppm de flúor + 0,5 ppm de manganês (F:Mn = 2,0); 4) 1,0 ppm de flúor +1,0 ppm de manganês (F: Mn = 1,0). Foram anotados o peso ganho e o consumo de alimento e água, durante os 60 dias de experimento, após o qual as patas traseiras, dos animais sacrificados, foram autoclavadas e desossadas, e os femures retirados. Posteriormente, foram estes submetidos à secagem, extração da gordura, pulverização e analise do flúor fixado. Também foram efetuadas analises da composição centesimal da ração e de flúor e manganês nesta e nas diferentes águas de consumo. Os resultados de percentagem do flúor ingerido fixado nos femures, foram analisados estatisticamente pelo teste não-paramétrico de Kruskal-Wallis (níveis de 1% e 5%) mostrando que, para as proporções consideradas, o flúor na taxa de 1 ppm, o manganês, quando administrado após o desmame, parece não afetar a fixaçao do flúor. Contudo, faz-se necessário dar continuidade aos estudos com novas proporções e taxas mais elevadas de flúor e manganês.An experiment to determine the effects of varying the manganese concentration of the diet on the fluorine retention in the femur of rats was made. Four groups of weaning rats were fed ad libitum a 27% casein synthetic diet and were provided with water as follows: 1) distilled (control); 2) containing 1 ppm of fluorine (F); 3) 1,0 ppm F + 0,5 ppm Mn; 4) 1 ppm F + 1 ppm Mn. The weight gain and food and water consumption were measured during 60 days. The results indicated that manganese does not seem to affect the proportional fixation of fluorine in the femur. The authors think that more data should be available before a definite conclusion on the influence of the ratio F:Mn on the fluorine retention could be drawn

State of binding of natural manganese in human cerebrospinal fluid, blood and plasma

IT was suggested earlier1,2 that the physiological behaviour of microconstituents of the body might not be reflected in nutritional, enzymological or even 'physiological' experiments conducted exclusively with pure or synthetic forms of these agents. More specifically, investigations using manganese additives to diets or to enzyme systems in vitro had been quoted as an illustration of experiments that might not bear directly on physiological parameters3. The basis for the reservation lay with the suspicion that these manœuvres might not result in quantitative duplication of the chelates, postulated to be characteristic of individual tissues and foodstuffs, and that, on the contrary, they might create artefactual complexes as well. It was conceded, however, that the natural state of binding of this element had not been investigated and that its natural chelates remained largely putative. © 1962 Nature Publishing Group