Changes in folate metabolism in baboons Papio cynocephalus treated with 2-methyl-2-aminopropanol-B12

After the intramuscular administration of the vitamin B12 analogue, 2-methyl-2-aminopropanol-B12, to vitamin B12-depleted baboons (Papio cynocephalus) the effects on vitamin B12 and folate metabolism have been studied. The 'apparent' serum vitamin B12 and the serum folate concentrations increased, the liver folate concentrations decreased, and the liver vitamin B12 concentrations were unchanged. The analogue caused a marked increase in the amount of formiminoglutamic acid excreted after a histidine load whereas the amount of methylmalonic acid excreted after a valine load decreased. The rate of red blood cell regeneration after venesection was normal in baboons treated with the analogue and there was no evidence of megaloblastic haemopoiesis. Two baboons given the analogue developed a partial loss of utilization and lack of co-ordination in the hind limbs.