血浆同型半胱氨酸与叶酸,维生素B12及还原酶的关系

目的 探讨叶酸、维生素Ｂ１２（ＶＢ１２）、血浆总同型半胱氨酸、５、１０－亚甲基四氢叶酸还原酶（ＭＴＨＦＲ）活性及其热敏感性基因型间的相互关系。方法 研究为３４例生育神经管畸形ＮＴＤＳ）儿的母亲及４２例生育正常儿的母亲,检测指标包括ｔＨｃｙ、红细胞叶酸、血清叶酸和ＶＢ１２、ＭＴＨＦＲ酶活性及热敏感性。ｔＨｃｙ、红细胞叶酸、血清叶酸在病例组与对照组间差异无统计学意义;ＮＴＤＳ患儿母亲ＶＢ１２显低于正

Relationship between folate, vitamin B12, total plasma homocysteine and mutation of reductase

OBJECTIVE: To study relationship between serum and red blood cell (RBC) folate, serum vitamin B(12) (VB(12)), total plasma homocysteine (tHcy), thermolabile genotypes, and activity of methylene-tetrahydrofolate reductase (MTHFR). METHODS: Thirty-four non-pregnant and healthy mothers who gave birth to babies with neural tube defects (NTDs) and 42 mothers to normal babies previously were chosen. Plasma tHcy, RBC and serum folate, serum VB(12), activity of MTHFR and thermolabile genotypes were determined for all of them. RESULTS: There was no significant difference in plasma tHcy, RBC and serun folate between case and control groups. Serum VB(12) was significantly lower in mothers of babies with NTDs than in those with normal ones. Plasma tHcy correlated with RBC folate inversely (P < 0.05). Mean plasma tHcy for thermolabile homozygous mutation of MTHFR was significantly higher than that for either heterozygous mutation or wild homozygous mutation (P < 0.001). There was no significant difference in serum folate between groups with varied MTHFR genotypes. Plasma tHcy was slightly greater in those with lower serum folate than in those with higher one, and correlated inversely with activity of MTHFR. CONCLUSIONS: Increase in plasma tHcy correlates with homozygous mutation of thermolabile MTHFR and decrease in activity of MTHFR. Higher level of folate in the body can interfere the relationship between plasma tHcy and activity of MTHFR.