Effects on bone loss of manganese alone or with copper supplement in ovariectomized rats - A morphometric and densitomeric study

Objective: The aim of this study was to examine the effect of manganese (Mn ) alone and with the addition of copper (Cu) in the inhibition of osteopeni a induced by ovariectomy (OVX) in rats. Study conditions: Four lots of 100- day-old female Wistar rats were divided into experimental groups of 15 each . One group received a diet supplemented with 40 mg/kg of Mn per kilogram o f feed (OVX+Mn). The second group received the same diet as the first, but with an additional 15 mg/kg of copper (OVX+Mn+Cu). The third group of 15 OV X and the fourth group of 15 Sham-OVX received no supplements. At the concl usion of the 30-day experiment, the rats were slaughtered and their femurs and fifth lumbar vertebrae were dissected. Femoral and vertebral length wer e measured with caliper and bones were weighed on a precision balance. The bone mineral content (BMC) and bone density (BMD) of the femur (F-BMC, mg a nd F-BMD, mg/cm(2)) and the fifth lumbar vertebra (V-BMC, mg and V-BMD, mg/ cm(2)) were measured separately with dual energy X-ray absorptiometry. Resu lts: The F-BMD, mg/cm(2) was lower in the OVX than in the Sham-OVX group (P <0.0001) and in the other two groups receiving mineral supplements (P<0.005 in both). F-BMC, mg was significantly lower in the OVX group than in the o ther three (P<0.0001 in all cases), Calculations for V-BMC, mg and V-BMD, m g/cm(2) are similar to findings in the femur. Conclusions: These data show that a Mn supplement is an effective inhibitor of loss of bone mass after O VX, both on the axial and the peripheral levels, although this effect is no t enhanced with the addition of Cu. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.