Effect of the exposure to circularly polarized magnetic field on the metabolism of pteridine and biogenic amines

2001 Fiscal Year Final Research Report Summary

• Project/Area Number: 12831001
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Institution: Chiba University
• Principal Investigator: MASADA Masahiro Faculty of Horticulture, Chiba University Professor, 園芸学部, 教授 (00229353)
• Co-Investigator(Kenkyū-buntansha): KATO Masamichi Hokkaido University, School of Medicine, Emeritus Professor, 医学部, 名誉教授 ; SHIGEMITSU Tukasa Bio-Science Department, Abiko Research Laboratory, Central Research Institute of Electric Power Industry, Head Researcher, 生物科学部, 上席研究員
• Project Period (FY): 2000 – 2001
• Keywords: magnetic field / pteridine / tetrahydrobiopterin / neopterin / mouse

Research Abstract

Tetrahydrobiopterin(BH4) is a putative cofactor for the hydroxylation of aromatic amino acids and its level has been indicated to regulate the initial and rate limiting enzymes in the pathway for biosynthesis of cateholamines and indolamines. Other pteridines, such as neopterin(NP) and pterin(AHP), are postulated to correlate with immunity and aging. It is reported that melatonin level is lowered by the exposure to circularly polarized magnetic field. The objective if this study is to determine the alteration of each pteridine level in mouse tissues under the exposure to circularly polarized magnetic field.
Five male mice per group, five week-old at the start, were used and exposed continuously to 0.5 mT circularly polarized magnetic field in period of 1,3 and 6 weeks. The sham-animal was exposed to stray field about 0.14 μ T. Mouse tissues were obtained after decapitation at the end of each exposure period and stored frozen at -80 ℃ until assayed. Data obtained from both groups were co mpared with that cage control group. Statistical significance of different between three groups was performed by Students's t-test
There were no difference if body weights among three groups. The level of NP and AHP in tissues from exposed group were significantly increased from other groups. BH4 content was significantly decreased in the exposed group, although total biopterin level was not different among three groups. No differences of GTP cyclohydrolase I and pyruvoyltetrahydropterin synthase activities were recognized among three groups.
These results suggests that BH4 biosynthesis is not affected by the exposure to magnetic field. The speculation leads to that the exposure to magnetic field may affect the reduction of quinonoid-dihydrobiopterin to BH4. The decreaqse of BH4 level may result in a lowering of amounts of ccatechoamines and indolamines. Further studies are carrying in the alteration of the neurotransmittance level under exposure to circularly polarized magnetic field and the effect of linearly polarized magnetic field on pteridine levels.