914MHz 대역 Radiofrequency Identification 전자파 노출이 흰쥐 호르몬계 및 뇌대사에 미치는 영향
Influence of Whole Body Exposure of 914 MHz Radiofrequency Identification on Endocrine system
- 발행기관 아주대학교
- 지도교수 안영환
- 발행년도 2013
- 학위수여년월 2013. 8
- 학위명 박사
- 학과 및 전공 일반대학원 의생명과학과
- 실제URI http://www.dcollection.net/handler/ajou/000000014940
- 본문언어 영어
- 저작권 아주대학교 논문은 저작권에 의해 보호받습니다.
초록/요약
Influence of 914 MHz Radiofrequency Identification on Neuroendocrine System and Cerebral Metabolism in Rats Radio frequency identification (RFID) is one of the currently introduced wireless radio frequency (RF) systems and is generally used in industrial and everyday life. However, the possible biologic effects of RFID radiation on human health, particularly brain function, remain unclear. Epidemiological studies suggest that exposure to RF electromagnetic field (EMF) may be a dormant risk factor in human health; therefore I expect it may affect the mammalian brain function. To study the effect of RFID exposure on rat brain function, I focused on neuroendocrine system including thyroid hormone system and melatonin, and cerebral metabolism, especially glucose metabolism. For these animal trials, a reverberation chamber was used as a whole-body exposure system. RFID exposure trial was performed during the day for the studies except for a study regarding the pineal melatonin biosynthesis, as RFID exposure during the night is more valid. The whole-body average specific absorption rate (SAR) was 4 W/kg for field of the RFID for all the experiments. Although some transient changes in serum thyroid hormones were observed in the separate 2, 4, 8, and 16 week exposure experiments, serum level of TSH and thyroid hormones were not influenced in this study. Nocturnal 8 h RFID exposure, at SAR of 4 W/kg, caused a reduction of a 24 h urinary secretion of 6-OHMS, melatonin metabolite, and its diminution degree shows a pineal Aanat transcriptional level-dependent manner. Decreased levels of AANAT enzyme activity and protein were observed in RFID exposed group compared to sham exposed group. Moreover, level of CREB phosphorylation in pineal gland was reduced after RFID exposure. Consequently, reduced expression of Aanat mRNA was also observed in RFID-exposed group. But, No significant change was found after RFID exposure in protein kinase A (PKA) enzyme activity which is known as a key enzyme in phosphorylation of AANAT and CREB in pineal gland at night. These results indicate that nocturnal RFID exposure reduces Aanat transcription which is ultimate causes of reduction of melatonin synthesis including protein level of AANAT and, AANAT activity. I investigated the RFID exposure influence on rat cortical glucose metabolism by using 18F-deoxyglucose positron emission tomography (FDG-PET). The relative cerebral glucose metabolic rate was unchanged in the frontal, temporal and parietal cortexes of the RFID-exposed rats, compared with rats in cage-control and sham-exposed groups. To evaluate the effect of RFID exposure on rat brain function, I had studied three different systems including cerebral glucose metabolism, thyroid system, and pineal melatonin synthesis. Taken together, my scientific data may, at least in part, provide evidence that rat brain can be influenced by RF exposure.
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ABSTRACT ………………………………………………………………………….………....i
TABLE OF CONTENTS …………………………………………………………………......iii LIST OF FIGURES …………………………………………………………………………..vii
I. List of Figures in Introduction……………………………………………………………vii
II. List of Figures in Results……..…………………………………………………………vii
LIST OF TABLES……………………………………………………………………………. ix
ABBREVIATION …………………………………………………………………………......x
I. INTRODUCTION………………………………………………………………………...….1
A. What is RFID? ………………………………………………………………….……...….1
1. RFID concepts……………………………………………………………..…...……..1
2. International guideline of RF energy absorption…………………………….…..…....2
3. RFID transmitting system……………………………...…………………….…..……2
B. Effects of EMF Exposure on Thyroid System…………………………………………......3
1. Thyroid system……………………………………….. …………………..…...…….3
2. Biological roles of thyroid system……………………..…………………….…..……3
3. Effects of EMF exposure on thyroid system…………..…………………….…..…...4
C. Effects of EMF Exposure on Melatonin Synthesis………………………………………...5
1. Biological roles of melatonin ………………………….…………………..…...…......5
2. Regulation of melatonin biosynthesis…………………….………………….…..…....5
3. Transcriptional regulation of rylalkylamine-N-transferase……………..….………....6
4. Effects of EMF exposure on melatonin synthesis ……………….………….…..…....6
D. Effects of EMF Exposure on Cerebral Metabolism…………………..………….….….....9
1. Cerebral glucose metabolism…………………………..…………………..….....…...9
2. Effects of EMF on cerebral metabolism………….......……………………...…….….9
3. Small animal PET scanning using 18F-FDG ………………….……………….….....10
E. Aims of This Study…………………………...………………………………………..…12
II. MATERIAL AND METHODS……………………………………………………............13
A. Whole-Body RFID Exposure System ……...…………………..……………………....13
1. Composition of Reverberation chamber………………………………..…..………..13
2. Measurement of field uniformity……………………………………….…..………..13
3. Calculation of SAR value…………………………………………………...…….…13
B. RFID Exposure Conditions……………………………………….………....….…...….15
C. Animal Experiments……………………………………………………………….…....17
1. RFID exposure experiment for thyroid system hormones …….…………..…….…..17
2. RFID exposure experiment for melatonin synthesis……………...……………..…..19
3. RFID exposure experiment for cerebral glucose metabolism…………………….…20
D. Enzyme Linked Limmunosorbent Assay (ELISA) ……..……………….………….….20
E. Heamatoxylin and Eosin Stain (H&E)……………………………………………..…...21
F. Gas Chromatography-Mass Spectrometry (GC-MS)…………………………………...22
G. Liquid Biphasic Diffusion Assay (AANAT activity assay)……..……………………..23
H. Western blot analysis……………….…………………………………………………..23
I. Reverse Transcription and Polymerase Chain Reaction (RT-PCR)…………………….24
J. Micro FEG PET……………………..…..………………………………………………24
K. Statistical Analysis………………...………………………………………………….. 27
III. RESULTS……………………………………………………………………..…….....28
Part A. Effects of RFID Exposure on Thyroid System; T3, T4 and TSH in Rat……….….28
1. Effect of RFID exposure on body temperature……………………………………....28
2. Effect of RFID exposure on body mass………………………………….…………..28
3. Changes in the SAR value…………….………………………………………..……29
4. Effect of RFID exposure on thyroid system hormone………………………...……..29
5. Effect of RFID exposure on thyroid gland follicles…..……………………..……….30
Part B. Effects of RFID Exposure on Melatonin Synthesis………………………….…….36
1. Effect of RFID exposure on melatonin biosynthesis in rat pineal gland…………….36
2. Effect of nocturnal RFID exposure on body temperature…………….……….……..36
3. Effect of nocturnal RFID exposure on concentration of plasma norepinephrine…....37
4. Effect of RFID exposure on AANAT activity ……………………………...….........37
5. Effect of RFID exposure on expression level of AANAT protein ………………….38
6. Effect of RFID exposure on regulation of Aanat gene transcription…………...……38
Part C. Effects of RFID exposure on cerebral glucose metabolism in rat:
A (F-18) FDG micro PET Study………...…...…………………...………………………....49
1. Effect of RFID exposure on cerebral glucose metabolism………………………..…..49
IV.DISCUSSION………………….……………………………………………………...….55
Part A. Effects of RFID Exposure on Thyroid System; T3, T4 an TSH in Rat…………..55
Part B. Effects of RFID Exposure on Melatonin Synthesis …………….…........…….….58
Part C. Effects of RFID exposure on cerebral glucose metabolism in rat:
A (F-18) FDG micro PET Study………………………………………………………….65
V. SUMMARY AND COCLUSION..………………………………………………………68
REFERENCES……………………………………………………………………...……….69
국문요약……………………………………..………………………………………………81
