Effect of alternating the magnetic feld on phosphate metabolism in the nervous system of Helix pomatia

The effect of extremely low frequency magnetic felds (50 Hz, 0.5 mT) - ELF-MF, on phosphate metabolism has been studied in the isolated ganglions of the garden snail Helix pomatia, after 7 and 16 days of snail exposure to ELF-MF. The infuence of ELF-MF on the level of phosphate compounds and intracellular pH was monitored by 31P NMR spectroscopy. Furthermore, the activity of enzymes involved in phosphate turnover, total ATPases, Na+/K+-ATPase and acid phosphatase has been measured. The exposure of snails to the ELF-MF for the period of 7 days shifted intracellular pH toward more alkaline conditions, and increased the activity of investigated enzymes. Prolonged exposure to the ELF-MF for the period of 16 days caused a decrease of PCr and ATP levels and decreased enzyme activity, compared to the 7-day treatment group. Our results can be explained in terms of: 1. increase in phosphate turnover by exposure to the ELF-MF for the period of 7 days, and 2. adaptation of phosphate metabolism in the nervous system of snails to prolonged ELF-MF exposure.

The Effect of Ginkgo Biloba Extract on Hypoxic Fraction of C3H Mouse Fibrosarcoma / 대한치료방사선과학회지

PURPOSE: To investigate the effect of Ginkgo biloba extract (GBE) on hypoxic cell fraction and metabolic status in fibrosarcoma (FSa II) of C3H mouse. MATERIALS AND METHODS: Fibrosarcoma (Fsa II), 6mm in diameter, growing in the right hindleg muscle of C3H mouse was used for estimation of hypoxic cell fraction using comparison of TCD50. Radiation was given one hour after administrationof GBE (100 mg/Kg, i.p.) with or without priming dose of GBE (100 mg/Kg, i.p.) given 24 hours earlier. Radiation was also given under air breathing condition or clamp hypoxia withour GBE as controls. 31P NMR spectroscopy was performed before and one hour after administration of GBE with or without priming dose of GBE. RESULTS: TCD50/120's were 81.7(77.7-86.0) Gy when irradiated under clamped hypoxia, 69.6 (66.8-72.5) Gy under air breathing condition,67.5(64.1-71.1) Gy with a single dose of GBE (100 mg/kg) given one hour before irradiation, and 62.2(59.1-65.5) Gy with two doses of GBE given at 25 hours and one hour before irradiation. The hypoxic cell fractions, estimated from TCD50/120's were 1.6% under air breathing ondition, 7.2% after single dose of GBE, and 2.7% after two doses of GBE. He results of 31P NMR spectroscopy were as follows. PCr/Pi ratio was 0.27 +/- 0.04 and 0.40 +/- before nd one hour after a single dose of GBE(p<0.01). These findings indicate that the metabolic status is slightly improved after a single dose and markedly after repeated administrations. CONCLUSION: GBE decreases the hypoxic cell fraction and improves the metabolic status of tumor, probably by increasing the blood flow and delivery of oxygen and nutrients, resulting in increased radiosensitivity of tumor.