1991 Fiscal Year Final Research Report Summary
Experimental study of photodynamic therapy on pituitary tumors
| Project/Area Number |
01480356
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Cerebral neurosurgery
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| Research Institution | Hiroshima University |
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Principal Investigator |
UOZUMI Tohru Hiroshima Univ., School of Medicine, Professor, 医学部, 教授 (20028426)
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| Co-Investigator(Kenkyū-buntansha) |
KURISU Kaoru Hiroshima University Medical Hospital, Assistant Professor, 医学部附属病院, 講師 (70201473)
KAWAMOTO Keiichi Hiroshima Univ., School of Medicine, Research Associate, 医学部, 助手 (10192006)
YANO Takashi Hiroshima Univ., School of Medicine, Research Associate, 医学部, 助手 (20239825)
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| Project Period (FY) |
1989 – 1991
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| Keywords | Photodynamic therapy / Pituitary adenoma / Pheophorbide-a / In vivo / In vitro / GH_3 cell / Growth hormone / Nude mouse |
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| Research Abstract |
From the basic study of photodynamic therapy (PDT) for rat pituitary tumor cells (GH3) using pheophorbide-a (Ph-a), the following results were obtained.
1, In vitro study
(1) The effect of PDT using Ph-a and white light against GH3 cells increases with the concentration of photosensitizer, intensity of irradiation, and incubation time.
(2) In view of the protective action of vitamin E against photosensitive action, it is assumed that the effect of PDT with Ph-a against GH3 cells is induced by hyperoxidation.
(3) PDT was effective against GH3 cells, malignant brain tumor cells, rat normal pituitary cells and human pituitary adenoma cells in vitro.
2. By employing fluorescence high performance liquid chromatography (fluorescence-HPLC), a method for the sensitive determination of the photosensitizer Ph-a in brain tissues and plasma was developed. Fluorescence-HPLC is an efficient method for determination of small amount of Ph-a in issues.
3. In vivo study
(1) Despite the delay in the disappearance of Ph-a from the tumor on the back of rats, Ph-a in the pituitary gland rapidly decreased after intravenous administration in vivo. Tbus, it is considered that by properly selecting the time interval from Ph-a injection to irradiation, it may be possible to attain cytocidal effect on pituitary adenoma without damaging the normal pitaitary.
(2) Through PDT, the tumor grossly disappeared, the plasma levels of rat growth hormone secreted from the tumor also remarkably decreased, and the development of giantism was inhibited. These results indicate that PDT is effective against rat pituitary tumor (GH3).
(3) When we used vitamin E solvent for dissolving Ph-a, pulmonary edema did not develop 72 hours after intravenous injection and a decrease of body weight due to intravenous injection of Ph-a was not observed.
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