AIN93G diet without manganese carbonate was used as a simple low-manganese diet, and the extent to which manganese status is reduced when it is administered to growing rats was examined. Twelve 4-week-old male Wistar rats were divided into two groups, one of which received the AIN93G diet (manganese concentration, 10 μg/g) and the other the AIN93G diet without manganese carbonate (manganese concentration, 0.3 μg/g) for 4 weeks. There was no difference in rat growth between the two groups, and no clinical signs related to manganese deficiency were observed at all in the low-manganese diet group. Organ manganese concentrations were clearly reduced by the low manganese diet, with values in the low manganese group being 28.4% of the control group in the liver and 49.3% of the control group in the kidneys. Arginase activity in the liver was also significantly decreased in the low manganese group, but the decrease was not as pronounced as in the manganese concentration, as 79.2% of the values were maintained in the low manganese group compared to the control group. In serum biochemical tests, the low-manganese diet group showed slightly but significantly higher serum iron concentration and transferrin saturation than the control group. To induce manganese deficiency with a simple low-manganese diet, it may be necessary to administer a low-manganese diet immediately after weaning for multiple generations.
