Effects of Long-Term Dietary Manganese and Copper Deficiency on Rat Skeleton

Abstract

Experiments were designed to produce biochemical changes in both serum and bone in rats by long-term dietary deficiencies of manganese (Mn) and copper (Cu). Weanling rats were fed one of three diets: 1) normal Mn and Cu (N), 2) low Mn and Cu (L) and 3) depleted Mn and normal Cu (D). After 12 mo, serum Ca and P were significantly greater in the D rats than the N rats (134, 50 mg/L and 103, 39 mg/L, respectively). Serum and femur Mn levels were lower in D rats than in normal rats. Serum and femur Cu levels were lower in L rats than N rats. Femur Ca concentrations were significantly lower in D rats than in N rats (180 and 272 mg/g, respectively). Radiographic differences could be detected in some rats fed the L and D diets. In the two deficient groups, increased serum Ca was negatively correlated with bone Ca (r = -0.69; P less than 0.01). This biochemical association may represent alterations in regulatory control of Ca at the level of the bone (decreased mineralization) combined with an increase in bone resorption. The effect of long-term dietary deficiencies in Mn and Cu should be considered in human bone metabolism.

Effect of dietary copper intakes on biochemical markers of bone metabolism in healthy adult males

“…However, there is some evidence that Cu de®ciency in¯uences bone resorption. An increased rate of bone resorption has been suggested as one explanation for the reduced bone mass observed in Cu-de®cient rats (Strause et al, 1986). Furthermore, studies carried out in vitro have shown that Cu reduces active bone resorption, as measured by release of 45 Ca or hydroxyproline into the bathing medium from cultured explanted 45 Ca-labelled mouse calvaria bone grown in medium with or without the addition of Cu (Wilson et al, 1981;Katz et al, 1984).…”

No effect of copper supplementation on biochemical markers of bone metabolism in healthy young adult females despite apparently improved copper status

“…Osteoclasts are known to produce superoxide and decreased activities of this enzyme could conceivably lead to increased bone resorption (Rico, 1991). An increased rate of bone resorption has been suggested as one explanation for the reduced bone mass observed in Cu-de®cient rats (Strause et al, 1986). Furthermore, studies carried out in vitro have shown that Cu reduces active bone resorption, as measured by release of 45 Ca or hydroxyproline into the bathing medium from cultured explanted 45 Ca-labelled mouse calvaria bone grown in medium with or without the addition of Cu over a 48 h period (Wilson et al, 1981;Katz et al, 1984).…”

Systematic analysis of molecular and physiological synergic effects of iron, manganese and copper on connective tissue

“…[42]. В эксперименте эффекты долгосрочно-го дефицита марганца и меди в диете включают снижение минерализации в сочетании с увеличе-нием резорбции кости [43]. Хронический дефицит марганца и меди приводит к снижению активно-сти строящих кость остеобластов, увеличению резорбции костного матрикса и, следовательно, снижению плотности и массы костей.…”

“…Рентгенограммы плечевых костей указали на присутствие многочисленных очагов повреж-дения кости как при сочетанном дефиците Mn/Cu, так и при глубоком дефиците марганца (рис. 4) [43].…”

“…N -нормальные уровни марганца и меди в диете; L -диета с сочетанным дефицитом марганца и меди; D -диета, в которой полностью отсутствует марганец при нормаль-ной обеспеченности медью [43].…”