Changes in the tissue concentration of folate and vitamin B(12) during maturation and ageing.
Age-dependent changes in folate and vitamin B(12) metabolism of mice have been investigated. The concentration of folate in liver plasma and blood showed a postnatal increase to a maximum at approx. 25 weeks. Total folate concentrations then remained constant whereas free folate decreased slowly up to week 98. Conversely both total and free folate of the brain were reduced extensively during the first 10 weeks of life after which time total folate concentration stabilised whilst that of free folate continued to decline slowly. The concentration of vitamin B(12) in brain, liver and plasma showed an initial rapid increase. The vitamin continued to accumulate more slowly in the brain and liver from weeks 10 to 98. The concentration of vitamin B(12) in the plasma appeared to achieve equilibrium after a period of accumulation lasting 25 weeks. These results suggest that during maturation the characteristics of folate metabolism of the brain are distinct from those of peripheral tissues, and that folate, unlike vitamin B(12) metabolism, undergoes continuing change with advancing age.
Hutchins
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DA
School of Pharmacy, Leicester Polytechnic, Leicester, LE1 9BH, U.K.
Ball
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PE