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Biochemical Studies on the Effect of Maternal Hyperphenyl‐alaninemia on Fetal Brain Maturation of Mice
Author(s) -
YAMAWAKI Yasushi,
OHYA Noriaki,
SHIMADA Morimi
Publication year - 1988
Publication title -
congenital anomalies
Language(s) - English
Resource type - Journals
eISSN - 1741-4520
pISSN - 0914-3505
DOI - 10.1111/j.1741-4520.1988.tb00580.x
Subject(s) - hyperphenylalaninemia , cerebrum , offspring , phenylalanine , pregnancy , endocrinology , medicine , biology , fetus , nucleic acid , gestation , amino acid , biochemistry , central nervous system , genetics
The effects of maternal hyperphenylalaninemia during pregnancy on the biochemical maturation of neonatal mice brains were examined, thus establishing the critical concentration of phenylalanine in maternal blood and the critical period of maternal hyperphenylalaninemia during pregnancy. Hyperphenylalaninemia was induced by giving chow supplemented with 3%, 4%, 5%, or 6% phenylalanine (Phe.) and 0.12% p‐chlorophenylalanine (PCPA) for at least one month and then throughout pregnancy. Some of the pregnant mice fed the 6% Phe. diet before pregnancy received a normal diet after conception (6%: A). Offspring from each group were decapitated two days after birth. Their brains were removed and then divided into the cerebrum and the brain stem including the cerebellum. Total protein, RNA and DNA were measured biochemically. All kinds of markers of the newborn mice born to the 5% and 6% mothers, the weight and the contents of the protein, RNA and DNA, were reduced significantly in both the cerebrum and brain stem. In the 4% group, however, only the brain stem was affected. The 3% group showed reductions neither in the weight nor the protein and nucleic acids contents in both the cerebrum and brain stem. In the 6%:A group, in which the diet was returned to normal just after conception, total protein, RNA and DNA were reduced in the brain stem, but not in the cerebrum. These results suggest that the critical concentration of maternal blood phenylalanine during pregnancy in the mouse is 11mg/dl, which is that corresponding to the 3% group, and also suggest that it is too late to begin the low phenylalanine diet after conception.