| Co-Investigator(Kenkyū-buntansha) |
IWASAKA Masakazu UNIVERSITY OF TOKYO,GRADUATE SCHOOL OF MEDICINE, LECTURER, 大学院・医学系研究科, 講師 (90243922)
ANDO Joji UNIVERSITY OF TOKYO, GRADUATE SCHOOL OF MEDICINE, PROFESSOR, 大学院・医学系研究科, 教授 (20159528)
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| Research Abstract |
In the present study, a possible influence of intense magnetic fields on cleavage patterns during the early embryonic development of frogs was studied.
We developed a microscope for real-time in situ observation of samples under superconducting magnet's bore. The eggs were exposed to horizontal magnetic fields, which were vertical to the animal-vegetable axis of eggs. Xenopus eggs with and without intense magnetic fields of up to 14 tesla were carefully observed during first to fifth cleavage for 3 hours. The normal control eggs showed vertical first and second cleavage planes and horizontal third planes, however, magnetic field exposed eggs tended to have declining third planes. By real-time observation under magnetic fields, almost 75% of eggs cleaved abnormally, and the number of abnormal declining cleavage lines increased depending on the magnetic flux density. Nevertheless, the percentage of abnormal tadpoles was the same between the control and the eggs cultured in magnetic fields. No teratogenic effects of an intense static magnetic field of 14 T were confirmed. The results indicated that early cleavages in Xenopus laevis were disordered by magnetic fields of 10 T order, independent on the magnetic field directions. The magnetic field effect did not remain until when they become tadpoles.
Also, we studied the properties of diamagnetic biological materials in static magnetic fields up to 14 T.We observed the phenomenon that the distribution of protein and cells became inhomogeneous around the center of the magnet. We also studied the possible effects of magnetic fields on the endothelial cell orientation. The cells oriented along the magnetically aligned collagen fibers. By utilizing near-infrared-oxygen monitor, oxy-/deoxy-hemoglobin concentration in a rat's head was measured under 8 T magnetic field, and discovered that the strong magnetic fields increased the population of oxyhemoglobin in rat tissue.
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