VIII-Ⅱ-1. Project Research
Project 1

PR1

Trace Elemental Analysis Using Research Reactor

K. Takamiya
Research Reactor Institute, Kyoto University
Objective: Elemental analysis is the most fundamental
experiment in many fields of research, for example,
chemistry, physics, biology, environmental science, medical science, and there are various method for elemental
analysis. Neutron activation analysis (NAA) is one of themost sensitive and accurate analytical method. But not allelements can be determined by NAA method with highaccuracy. In NAA method, analysis samples are irradiatedby neutrons to produce radioactive isotopes in samples,and energy spectra of gamma-rays emitted from the isotopes are measured to determine elements contained insamples. If produced radioisotopes have too short or too
long half lives, obtaining enough statistics in gamma-ray
measurements becomes very difficult. And if there exists
too many elements in a sample matrix such as biologicalsamples, the accuracy of gamma-ray spectrometry decrease because of the Compton Effect and overlap ofcomplicate photo peaks. In order to eliminate these disturbances, various techniques have been developed, forexample, Anti-Compton method can reduce Compton
background caused by short-lived products.
Research Subjects: Two types of approach, hardware
development and methodological improvement, havebeen performed to increase the precision of NAA methodin this project research. In the approach by hardware development, Prompt Gamma-ray Analysis (PGA) system
and Anti-Compton Spectrometer (ACS) system havebeen developed and installed. The PGA system is connected with Super Mirror Neutron Guide Tube at B-4
beam hole of KUR which can supply high-quality thermal neutron beam. The ACS system is installed at next totwo of pneumatic capsule transporting systems (Pn-1 andTC-Pn) of KUR to detect short-lived nuclei effectively
without the Compton background. In another approach of
methodological improvement, developing and applying
new NAA techniques have been tried to actual elemental
analysis experiments. The respective subjects of the research groups of this project are described as follows;
P1-1: Measurements of neutron spectrum transition for
high-precision NAA
P1-2: Development of prompt gamma-ray analysis apparatus in KURRI
P1-3: Antimony and arsenic concentration distribution in
depth direction around a smelter
P1-4: Neutron activation analysis of elements in mineral
type natural medicine ‘Ryukotsu”
P1-5: Multi-element analysis of domestic green tea by
neutron activation analysis
P1-6: Biodistribution of gadolinium-based contrast agent,and concentration of manganese and zinc in normal andnephrectomized mice

Results: Hardware developments have been completed.
And applications of the hardware and methodologicalapproaches for NAA experiments have been performed in
the final period of this project. The brief summaries ofthe performed subjects are as follows;
P1-1: The gold applied PET sheets as neutron monitors
enclosed in irradiation rabbits were irradiated to examine
the neutron energy spectra and its variation in the irradiation hole of KUR. The five monitors were irradiated byneutrons in Pn-2 irradiation hole in 10 minutes with aninterval of 1.5 hours after the thermal power of KUR
reached 1 MW. The axial distributions of activities of198
Au and 122Sb in the rabbit were estimated by processing the picture obtained from the imaging plate. It was
found that neutron distributions estimated by each isotopechange over time, and magnitude of the change is different between 198Au and 122Sb. This means the neutron
spectra at the irradiation hole became softer while thefive times irradiations. The magnitude of change is small
but nonnegligible in highly precise NAA.
P1-2: Both neutron radiography and elemental analysis
for a pottery sample have been performed simultaneously.
For the elemental analysis, PGA installed at B-4 beamline was used. Since elemental analysis for such as thepottery without the appropriate reference standards at thepresent stage of the installed system, a part of the sample
was subjected to NAA to determine the elements.
P1-3: Antimony pollution characteristics in soil samples
collected around an antimony smelter at Maibara has
been estimated using NAA method and compared to thepollution characteristics of arsenic. Obtained distributionof antimony shows a decreasing tendency with increasing
the depth, on the other hand arsenic concentrations are
considered to be background level.
P1-4: The relationship between elemental contents ofmineral type raw material, called “Ryukotsu” and effectiveness is unclear. To clarify this relationship, NAA for
Ryukotsu samples were performed under several conditions. The role of Ryukotsu in herbal medicine must be
clarified using the obtained results in future studies.
P1-5: To estimate the amount of elements taken fromdrinking green tea, several kinds of domestic green tea
were analyzed by NAA.
P1-6: The distribution of Gd and concentration of someminerals in selected tissue of four experimental condition
applied mice was measured by NAA method. The
nephrectomized mice showed high Gd retention in eachtissue compared to normal mice. No correlation of “exogenous” Gd and “endogenous” Zn was confirmed.
However, it is not sufficient to achieve with statistically-warranted value of the biodistribution of “exogenous”
Gd and the concentration of “endogenous” and “exogenous” trace elements in normal and nephrectomized mice
to clarify the correlation of Gd with trace elements.

採択課題番号 23P1
原子炉中性子を用いた微量元素分析（京大・原子炉）高宮幸一

プロジェクトMeasurements of 1eutron 6pectrum 7ransition for +igh-precision NAA

Research Reactor Institute, Kyoto University
INTRODUCTION: Distributions of neutron flux andenergy spectrum at neutron irradiation fields affect estimations of nuclear reaction rate. Precise measurement of
the distributions is important for neutron irradiation experiments such as neutron activation analysis, radio isotope production, etc. A new measurement method forneutron flux distributions using a gold-applied thin sheet
as a neutron monitor has been developed [1]. In thismethod, gold solution is applied on a printing sheet by acommercially available ink-jet printer to prepare a neutron monitor materials. The prepared neutron monitor isthin enough to ignore the self-absorption in neutron irradiation and self-shielding effect in gamma-ray measurement. The distribution of neutron flux can be visualizedeasily by means of an imaging plate in radiation measurement for the neutron-irradiated monitor. In the previous report, the neutron distributions of neutron irradiation
holes (Pn-1, -2, -3, and TC-Pn) of Kyoto University Research Reactor (KUR) has been measured by this method.
The gold solution was applied on the half-side of a PET
sheet to prepare the neutron monitor in the work, anddistributions of radioactivity of products ( 198Au and 122Sb
which is produced by neutron capture reaction of 121Sb
containing in a PET film) was measured using imaging
plate. A difference of the production ratio of radioactivityof 122Sb to that of 198Au indicates a difference of spectraof irradiated neutrons. In the present report, distributionsof the neutron energy spectrum were examined by themonitor.
EXPERIMENTS: The gold applied PET sheets asneutron monitors enclosed in irradiation rabbits were
irradiated to examine the neutron energy spectra and its
variation in the irradiation hole of KUR. The detailed
preparation scheme of the monitor is described in theprevious report. The five monitors were enclosed in separated irradiation rabbits and irradiated by neutrons in
Pn-2 irradiation hole in 10 minutes with an interval of 1.5
hours after the thermal power of KUR reached 1 MW.
After cooling time of one day, the irradiated monitor was
separated to two pieces, one is applied on by gold and theother is not, and distributions of radioactivities producedin the monitor pieces (198Au and 122Sb for the former, and122
Sb for the latter) were measured by the imaging platefor 5 min of the exposure time.
RESULTS: The axial distributions of activities of198
Au and 122Sb in the rabbit were estimated by processing the picture obtained from the imaging plate andshown in Fig.1. The relative radioactivities in each 3.5mm range are shown in this figure. Activities are normalized to the average activity on reaching the thermal power 1 MW. Symbols indicate the time variation of the distributions. It is found the time variation for 122Sb production is larger than that for 198Au. The transition of activity
ratio of 122Sb / 198Au shows the change of irradiated neutron spectra. The time variation of activity ratio of 122Sb /198
Au is shown in Fig. 2. The values are normalized to theratio on the reactor power reaching 1 MW in this figure.
The ratio decrease with the elapsed time and reaches 95%
after 6 hours. This means the neutron spectra at the irradiation hole became softer while the five times irradiations. The magnitude of change is small but
non-negligible in highly precise NAA.

110
122

Sb

100
Relative activity

K. Takamiya, M. Takimoto, S. Shibata, R. Okumura andY.Nakano

90

110

80

100
198

Au

0

2

4

6

0h
1.5 h
3h
4.5 h
6h

8

90
80

range (top to bottom) / cm
Fig. 1. The axial distributions of produced activities of198
Au and 122Sb in the rabbit.

Relative activity ratio(122 Sb / 198 Au)

PR1-1

100

95
0

2
4
elapsed time / h

6Fig. 2. The time variation ofactivity ratio of 122Sb / 198Au.
REFERENCES:[1] K. Takamiya, M. Takimoto, S. Shibata, R.
Okumura, Y. Nakano, J. H. Moon, S. H. Kim, Proc.
Radiochim. Acta 1 (2011) 63–66

採択課題番号 23P1-1 中性子放射化により生成する短寿命核種の定量法の開発（京大炉）高宮幸一、瀧本真己、柴田誠一、奥村良、中野幸弘

プロジェクトDevelopment of Prompt Gamma-ray Analysis Apparatus in KURRI

PR1-2

S. Sekimoto, Y. Saito, Y. Homura, M. Ebihara1, Y. Kawabata, K. Takamiya, and R. Okumura
Research Reactor Institute, Kyoto University
1
Graduate School of Science, Tokyo Metropolitan University
INTRODUCTION: Prompt gamma-ray analysis (PGA)
apparatus has been developed in KURRI from 2008.
This development is promoted by Nuclear Energy Research Initiative, Research Reactor and Hot Laboratory
Utilization program, which is titled as “Improvement of
Utilization on KUR and HL in KURRI”, under the project in Ministry of Education, Culture, Sports, Scienceand Technology. In PGA, it is necessary to observe the
gamma rays emitted promptly from the samples throughneutron induced reaction. The neutron irradiation for
PGA in KURRI will be carried out at B4 reactor site of
Kyoto University Reactor (KUR). The purpose of thisproject is to install the PGA in KURRI and to apply the
total micro-element analysis system including the PGA
and the short-lived nuclides measurement system, which
has been developed under the same program, to the research on medical science, archeology, cosmo- andgeo-science etc., in the future. In terms of the field of
nuclear energy, this project is also directed toward theideal model of small neutron source in university.
Inthis report, the state of preparation for installation of the
PGA system in KURRI is described.

MOTIVATION: Neutron radiography has been applied
to industrial quality tests and to various research activities as a non-destructive imaging technique utilizing neutrons. Neutrons have many advantages for imaging overvisible light, X-rays or electrons. The distinctiveness ofneutron radiography rests on the characteristic interactions between neutrons and nuclei. This leads to somespecial relationships between the material and geometrical properties of an object and the neutron radiographic
image. The neutron image provides integrated absorption
rates of neutron in the object along the neutron path, but
no information about elemental components for material
itself.
PROGRESS in 2011: In this work, we attempt to get
the neutron radiographic image and also to get information about elemental components simultaneously inthe pottery sample using neutron. To get information
about elemental components, PGA at the B-4, which has
been carried out using a single germanium detector andappropriate shielding surrounding the detector, is utilized[3]. The pottery sample is the replica of the archeological sample, supplied by IAEA. The sample is measured inthis work in order to confirm the applicability of large
sample analysis by PGA for inhomogeneous bulk archeological samples in the future.
Since it is difficult to get results of elemental analysis
for the pottery by PGA without the appropriate reference
standards at the present stage, a part of the pottery sample
was crushed and pulverized, and was subjected to instrumental NAA using KUR. Measured elemental contents obtained by NAA in the five part of the pottery
sample are shown in Table 1, and they will be comparedto PGA results in the future.

PREPARATION: Kyoto University Research Reactor
Institute has the neutron radiography facility at B-4 beamhole, where a supermirror neutron guide tube has been
installed [1]. The details of neutron beam and the imaging devices for neutron radiography at B-4 beam holewere reported elsewhere [2]. At B-4 beam hole, thePGA system has been developed to make it possible to
REFERENCES:
measure some light elements such as H, B, Si, S, etc.
[1] Akiyoshi T, Ebisawa T, Kawai T, Yoshida F, Ono M,
which were not able to be measured by the conventional
Tasaki S, Mitani S, Kobayashi T, Okamoto S (1992) J
neutron activation analysis (NAA). Since the B-4 beam
Nucl Sci Tech 29:939-946[2] Saito Y, Sekimoto S, Hino M, Kawabata Y (2011)
hole has the end of the supermirror neutron guide and is
Nucl Instr and Meth A. 651:36-41
located outside the reactor room, the B-4 is appropriate
for the installation of the PGA system which requires low[3] Sekimoto S, Saito Y, Homura Y, Ebihara M, Kawagamma-ray background. Consequently the B-4 bebata Y (2012) 7th International Topical Meeting on Neucomes the unique facility, where not only neutron raditron Radiography, June 16-22, Kingston, Canada.
ography but also PGA and even in nuclear fission experiments can be performed.
Table 1. Measured elemental contents in the pottery sample
Na
Mg
Al
Ca
Ti
V
Mn

Pottery_1
Contents (%)
1.93 ± 0.06
2.13 ± 0.17
7.81 ± 0.28
3.2 ± 0.5
0.44 ± 0.11
0.013 ± 0.001
0.085 ± 0.001

Pottery_2
Contents (%)
2.11 ± 0.08
2.17 ± 0.15
7.80 ± 0.12
2.7 ± 0.4
0.45 ± 0.08
0.013 ± 0.001
0.089 ± 0.001

Pottery_3
Contents (%)
2.02 ± 0.08
2.11 ± 0.16
8.62 ± 0.13
3.7 ± 0.5
0.40 ± 0.08
0.015 ± 0.001
0.087 ± 0.001

Pottery_4
Contents (%)
2.10 ± 0.07
2.17 ± 0.15
8.48 ± 0.13
3.4 ± 0.4
0.45 ± 0.08
0.014 ± 0.001
0.087 ± 0.001

Pottery_5
Contents (%)
2.06 ± 0.09
2.33 ± 0.16
8.76 ± 0.15
3.2 ± 0.5
0.45 ± 0.09
0.015 ± 0.001
0.091 ± 0.001

採択課題番号 23P1-2
京大炉における即発ガンマ線分析装置の開発
プロジェクト（京大・原子炉）関本 俊、齊藤泰司、布村優太、川端祐司、高宮幸一、奥村良（首都大・大学院・理工）海老原充PR1-3

Antimony and Arsenic Concentration Distributionin Depth Direction around a Smelter

S. Fukutani1), K. Takamiya1), Y. Nakano1), R.
Okumura1), T. Takahashi1) , M. Horiuchi2) and A.
Koyama1)
1) Research Reactor Institute, Kyoto University2) Department of Civil Engineering and Environment at
Design, Daido University
INTRODUCTION: Around antimony smelters andmines, very high levels of antimony pollution have been
detected and reported[1] [2] [3]; antimony pollution wasreported to affect the health of residents living in thevicinity of a smelter [4]. Antimony smelters are usuallybuilt in areas remote from residential areas. City waste
incinerators, which are now established in every local
government area, are more important sources of
antimony pollution than smelters for the general public.
Because samples collected around antimony smelters
contain high levels of antimony, design of anexperimental system to measure the samples is easy. We
aimed to study antimony pollution characteristics andbehavior around smelters and a mine, and apply the
results to antimony environmental contamination in
general. In this study, we estimated antimony pollution
characteristics in soil samples collected around an
antimony smelter at Maibara (Shiga-pref.) by comparing
with pollution characteristics of arsenic.
EXPERIMENTS:
The soil sample was collectedaround an antimony smelter at Maibara-city in Shiga-prefecture where health hazards had been occurred in1970's (Fig. 1). The collected soil was dried in air andsieved through a 2mm sieve. About 100 mg soils of these
pretreatment soils were prepared for INAA. Soil samples
were irradiated by neutron at Pn-2 of KUR (thermal neutron flux: 5.5 × 1012 n･cm-2･s-1). BCR-176 (city waste
incineration ash; certified value of antimony is 412 mg･kg-1) for comparison standard of antimony and
SRM-2711a (Montana II soil, moderately elevated traceelement concentrations; certified value of arsenic is 107
mg･kg-1) for that of arsenic were used. Irradiation timewas 10 minutes, and after about one day for cooling,
γ-ray spectrometry was conducted. Concentrations of
antimony and arsenic were calculated by using comparison method.
RESULTS: Measurement results about antimony andarsenic in the Maibara soils were plotted in Fig. 2. Antimony concentrations showed a decreasing tendency withincreasing depth, on the other hand arsenic concentrations at Maibara area were considered to be background

採択課題番号 23P1-3（京大・原子炉）福谷

Fig. 1 Soil sampling point

Fig. 2 Antimony and arsenic concentrations in the soil samples
at Maibara area. Sb 1 and As 1, or Sb 2 and As 2 are respectively derived from the same core sampling.
level, and only little changes of concentrations along withdepth were recognized.
REFERENCES:[1] Ainsworth N, Cooke J A, Johnson M S (1990) Environmental Pollution 65: 65-77[2]Ainsworth N, Cooke J A, Johnson M S (1991) Water,
Air and Soil Pollution 57-58: 193-199[3]Wilson N J, Craw D, Hunter K (2004) Environmental
Pollution 129: 257–266[4]Ishida N, Katayama Y (1978) Kagaku 48: 509-515 (inJapanese)

土壌中微量環境負荷元素の汚染経路の解明に関する研究
哲、高宮幸一、高橋知之、中野幸広、奥村 良

プロジェクトPR1-4 Neutron Activated Analysis of Elements in Mineral Type Natural Medicine “Ryukotsu”
M. Kawase, T. Saito1, Y. Nakano2 and K. Takahashi3,4Faculty of Bioscience, Nagahama Institute of Bio-scienceand Technology
1Radioisotope Research Center, Osaka University
2
Kyoto University Research Reactor Institute
3Graduate School of Pharmaceutical Sciences, Osaka
University
4Museum, Osaka University

The plant is one of the important raw materials of the herbal medicine. Moreover, the animal, reptiles, insect and minerals are also
the important raw materials of the herbal medicine.
The effect of the herbal medicine is largely affected by
the home and the quality of the used raw materials.
The metal elements are considered to be related with
the quality of herbal medicine. Especially, the relationship between elemental contents of mineral typeraw material, called “Ryukotsu” and effectiveness is
unclear, and a study to clarify the relationship is hardly done [1].
To clarify this relationship, analyses of elements in
Ryukotsu were done under several conditions. In thisreport, we show the obtained results.

INTRODUCTION:

EXPERIMENTS:

The used Ryukotsu was commer-

cial base material for herbal medicine. In preparationof herbal medicine, Ryukotsu and other raw materials
were mixed and extracted by hot water. Four types of
Ryukotsu were prepared depending on the extracting
conditions, and subjected to activation analysis. Types
1, 2, 3 and 4 were Ryukotsu before extraction, after
extraction without others, after extraction with others
and type3 washed with water after extraction, respectively. In activation analysis, all samples were irradiated for 1 min and 60 min in KUR, and gamma-ray
energy spectra of samples were measured for 200 seconds by Ge detector.

ditions.
Mn, Na, V, S and Cl showed behavior like the Ca.
Zn showed behavior like the Al. The other elements
had a large error, and their behavior did not become
clear.
The role of Ryukotsu in herbal medicine must be
clarified using these results in future studies.
REFERENCES:[1] Ministry of Health, Labour and Welfare “Nihon

Yakkyokuho” (2011),

http://www.mhlw.go.jp/topics/bukyoku/iyaku/yakkyoku/

Fig. 1.

Content of Ca in each type of Ryukotsu
Types 1, 2, 3 and 4 were Ryukotsu before extraction, after extraction without others, after extraction with others and type3 washed with water
after extraction, respectively.

RESULTS: Ryukotsu is defined as the fossil ofmammals at Mesozoic era. As standard sample forquantitative analysis for fossil, semi-quantitative analysis of elements in Ryukotsu was done in this study.
The results about Ca and Al were shown Figs. 1 and 2,
respectively.
From these results, Ca content in Ryukotsu was littlechanged by extraction in all conditions. However, thecontent of Al was largely changed depending on con-Fig. 2.

Content of Al in each type of Ryukotsu.

採択課題番号 23P1-4
放射化分析による鉱物生薬“竜骨”の元素分析
プロジェクト（長浜バイオ大）川瀬雅也、（阪大・RI センター）斎藤 直、（京大・原子炉）中野幸廣（阪大院・薬、阪大博物館）高橋京子

PR1-5Multi-element Analysis of Domestic Green Tea by Neutron Activation Analysis

M. Fukushima, A. Yoshihara, Y. Nakano1 and R. Okumura1

water were used for comparison. After making drinking green tea, the residue green tea was freeze dried, andpulverized.

Department of Sciences and Engineering, Ishinomaki
Senshu University
1
Research Reactor Institute, Kyoto University

RESULTS:
Concentrations obtained for domestic
green teas analyzed by long life nuclides are shown in
Table 1. Cs, Sc, Rb, Fe, and Co levels showed differences between the location of tea production and speciesof green tea trees. Ratios of elements extracted indrinking green teas are shown in Table 2. Blanc cells
caused that peaks were not found or ratio was bigger
than 1.00.

INTRODUCTION
Drinking green tea is taken daily well in Japan.
To estimate the mount of elements taken from drinking
green tea, several kinds of domestic green tea were analyzed by neutron activation analysis.
EXPERIMENTS:<Samples>Three different kinds of powder teas and seven different
kinds of green teas were obtained from one green tea
company. Five of different kinds of green tea were;
Sayama-Cha, Uji-Cha, Uresino-Cha, Yame-Cha, andKagoshima-Cha. Rest of two green teas were two different species of tea tree from Kagoshima; Okumidori andAsatsuyu. Powder teas were used for analysis without
any treatment. Each green tea was pulverized by mill.
<Neutron activation analysis>
About 0.5 g of samples were sealed in plastic bags andirradiated. Each samples were irradiated three different
condition; Ti : Td : Tc = 20 sec : 60 sec : 100 sec, 1min :1 min : 10 min, 4 h : 1 month : 30 min. NIST SRM
1646a Estuarine Sediment, NIST SRM 1633a Coal Fly
Ash, NIST SRM 1566b Oyster Tissue, BCR-60
Lagarosiphon Major, and JSO-1 Soil were used as comparator samples.
<Preparation of drinking green tea>
Drinking green teas were prepared from 2 g of green tea
and 80 mL of hot water with standard ceramic tea pot.
As for hot water, two kinds of tap water and distilled

Table 2. Ratios of elements extracted in drinking green tea
Element

U

Sayama

Th

Cs

0.23

Sc

Rb

Fe

0.48

0.49

Co

0.35

0.15

0.66

0.71

0.52

0.60

Uji

0.84

0.57

0.71

Ureshino

0.60

0.07

0.64

0.03

0.35

0.52

0.50

0.37

0.46

0.48

0.17

0.62

0.59

0.73

0.69

0.62

0.43

0.13

0.01

0.25

0.54

0.43

0.53

0.34

0.50

0.16

Yame
Kagoshima

0.27

Okumidori

0.04

Asatusyu

0.06

0.27

0.42

Zn

Table 1 .Elemental levels of domestic green teas (unit: μg/g, dry weight).

Element

Cr

U

Th

Cs

Sc

Rb

Fe

Zn

Co

Nuclide used
for analysis

Cr-51

U-238

Th-232

Cs-134

Sc-46

Rb-86

Fe-59

Zn-65

Co-60

Gamma enery

320.08

351.9

583.2

604.7

889.281076.6

1099.251115.55

1173.24

Half-life

27.7 d

2.06 y83.81 d18.66 d44.5 d243.9 d5.27 ySayama

1.0

0.13

0.017

0.03

0.022

14.6

86.5

35.7

0.158

Uji

1.0

0.09

0.012

0.14

0.021

21.0

69.6

40.4

0.156

Ureshino

1.5

0.12

0.014

0.05

0.016

21.0

60.6

37.8

0.271

Yame

0.7

0.12

0.013

0.05

0.026

17.1

82.7

34.4

0.227

Kagoshima

1.1

0.12

0.012

0.12

0.011

22.7

87.7

39.0

0.095

Okumidori

0.19

0.014

0.22

0.013

30.0

125.7

42.1

Asatusyu

0.15

0.015

0.12

0.012

25.4

145.5

35.6

採択課題番号 23P1-5
中性子放射化分析法による国産緑茶の多元素分析（石専大・理工）福島美智子、吉原 章 （京大・原子炉）中野幸廙、奥村

0.085

プロジェクト良PR1-6

Biodistribution of Gadolinium-Based Contrast Agent, and Concentration of Manganese andZinc in Normal and Nephrectomized MiceK. Washiyama, H. Tsujii, H. Takana, L. Keiko, Y. Sakaue,
R. Amano and K. Takamiya1
School of Health Sciences, College of Medical, Pharmaceutical and Health Sciences, Kanazawa University
1
Research Reactor Institute, Kyoto University
INTRODUCTION: Gadolinium (Gd)-based contrast
agents have been used in medical MR-imaging. However,human nephrogenic systemic fibrosis (NSF) is reported in
Gd-based contrast agent received patients with severe
renal insufficiency [1] and a depletion of endogenous Zn
ion may contribute in the development of NSF [2, 3]. On
the other hand, Pietsch et al. reported no correlation of
Zn with the NSF [4].
Gadolinium has a high activation cross section (1060barn) for thermal neutron and it is possible to detect sensitively by neutron activation analysis (NAA). NAA
technique also quantitates essential trace elements in vivo
such as Zn and so on. In this study, we measured distribution of Gd and concentration of some minerals in selected tissue of four experimental condition applied miceby using NAA.
EXPERIMENTS: Twenty male 8-week-old ICR strain
mice were used in this study. Ten mice were housed as
normal, and another ten mice were partiallynephrectomized, which were used as pseudo renal impairment model [5].Five mice in each group was administered 2.5 mmol Gd/kg b.w. Omniscan (gadodiamide)
intravenously. Two days after administration, mice weresacrificed and dissected. The blood, femur, kidney, andliver were excised and weighted. The samples were
freeze- dried and sealed into polyethylene bags for NAA.
The sealed samples and standard of gadolinium were
irradiated in Pn-3 for 30 second and in Pn-2 for 1 hour,for short and long half-life radioisotopes production, respectively. The distribution of Gd and concentration ofminerals were determined by using -ray spectrometry.
RESULTS AND DISCUSSION: The biodistribution ofgadolinium 2-d after administration was shown in Fig.1.
The kidney showed high Gd retention behaviors due tonormal process of excretion of Gd. Skeletal Gd distribution of model mice were significantly higher than that ofnormal mice. The nephrectomized mice showed high Gd
retention in each tissue compared to normal mice.
The concentration of Mn and Zn were shown in Fig.1
and Fig. 2. Manganese concentrations in kidney of model
mice decreased relative to normal mice. On the other
hand, Mn concentrations in liver were comparable during

four groups. Zinc concentration in the selected tissue
showed no difference during four groups of mice.
We confirmed no correlation of “exogenous” Gd and“endogenous” Zn. However, it is not sufficient to achievewith statistically-warranted value of the biodistribution of“exogenous” Gd and the concentration of “endogenous”
and “exogenous” trace elements in normal andnephrectomized mice to clarify the correlation of Gd withtrace elements.

Fig. 1. Biodistribution of gadolinium and Mn in selected tissues of normal and nephrectomized mice 2 dafter the omniscan administration. White bars showednormal mice and gray bars showed model mice, andthe bars with striped showed the groups of Gd administration.

Fig. 2. Concentration of zinc in the blood, femur, kidney, and liver of normal and nephrectomized mice 2 dafter the omniscan administration. White bars showednormal mice and gray bars showed model mice, andthe bars with striped showed the groups of Gd administration.
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[2] E. S. Harpur et al., Invest. Radiol., 28(Suppl 1) (1993)
S28-S43.
[3] J. H. Wible et al., Invest. Radiol., 36 (2001) 401-412.
[4] H. Pietsch et al., J. Magn. Reson. Imaging, 30 (2009)374-383.
[5] H. Pietsch et al., Invest. Radiol., 44 (2009) 226-233.

採択課題番号 23P1-6 MRI 用ガドリニウム造影剤による副作用「腎性全身性線維症」プロジェクトの発症機序の解明に関する研究 -アクチバブルトレーサー法の応用（原子炉中性子を用いた微量元素分析）（金沢大・保健）鷲山幸信、辻井陽香、高名はすか、李恵子、坂上優貴、天野良平（京大・原子炉）高宮幸一