Streptozotocin-induced diabetes is not a model for methylmalonic acidaemia

The streptozotocin-treated diabetic rat was not found to be a suitable animal model for methylmalonic acidaemia as previously described. Urinary methylmalonic acid (MMA) was measured in adult Wistar rats prior to and following injection of streptozotocin (40 mg/kg). Plasma and tissue MMA levels were measured following the induction of diabetes and compared with data from control rats. MMA levels were determined by a gas chromatographic-mass spectrometric method (McMurray et al., 1986). Diabetes was confirmed by the 10 x increase in 24 h urine volume; glycosuria; glycaemia; and weight loss. Urinary MMA excreted did not change during the 11 week diabetic period and there was no difference between the pre- and post-diabetic phases (p less than 0.05). Plasma and tissue MMA concentrations were not elevated in this diabetic animal model. Also in contrast to earlier reports, the vitamin B12 levels of the diabetic rats were not elevated compared to controls (p less than 0.05).