doses is! chemieal distribution of the }88Ba in various bones
parison * and types of bones (cortical vs. trabecular) throughout
owever, ' the dog skeleton.
This barium isotope was chosen because 1} it has a
system’
2 prob- ! long half-life of 7.2 years and is excellently suited for
cells.
| lony-term retention studies, 2) the radiation dose from
it is minimal (133Ba decays by electron capture and
ng 7 no beta particles are emitted), and 3) quantitative
mensurements are easily made by means of seintillation counters, that is, gamma counters for whole-body
retention data, and liquid seintillation counters for
oentgen
Am,
z4
Rays on
I;
‘tebrate ‘
Arbacta
blood, fecal, and chemically ashed samples.
MATERIALS AND METHODS
ach animal was given an intravenous injection of
133Ba in the form of BaCl, in 0.073 N HCl, with a
alay of i
TABLE 7.
ace 138,
adiated ®
331-340 |
of Sea .
A
ge at
injection
Dog
‘h June .
A22B
576
ed Sea *
Radio-
A22C
A22D
SARI eA aS
logical |
hrough |
).
nalian
§76
te to
man
1eas-agle
have
ntly, |
with }
take F
l10-
1
1
0.491)
0.464)
0.427]
0.420;
0.418]
0.371]
0.332]
0.307}
293
0.252] 0.361
5
1002
1199
S13}
3113
1508
10.5
7
=7.2 kg
10.0 kg
12.5 kg
B
0.667
0.647
0.589
0.588
0.610
0.509
0.460
0.401
0.224) 0.352
0.213) 0.319
0.173) 0.280
7
7
% injected dose/g calcium
1
I
0.895; 0.791
576
A22B| A22C A22D
0.667) 0.952!
0.636)
0.518}
0.460)
0.409)
0.354)
0.513
0.443
0.369
0.323
0.295
1.03
; 0.978] 0.818
0.816/ 0.703
0.327|
0.309}
0.285]
0.280/
0.279;
0.247)
0.221)
0.205}
0.635
0.616
0.561,
0.561
0.581
0.485
0.438
0.382
0.168) 0.344
0.149] 0.335
0.142) 0.335
0.115) 0.267
0.102) 0.277
0.1281 0.264
— 0.206
0.085) 0.251
0.196
0.105; 0.289
0.695]
0.566)
0.503;
0.447]
0.387)
Percent injected dose/mg calcium
Time,
days
0.021
0.042
0.098
0.167
0.25
0318
1
2
3
4
5
6
7
14
1002-1091
1100-1195
1450-1850
1765-1865
Bartum: Bioop Spreciric ACTIVITY
576
—
12.83 X
_
_
1.17 «
9
—
5.15 <
2.04 X
1.18 X
—
_
_
3.80 X
1.10 *
—|7.40 x
|4.65 x
—
A22B
A22C
_
3.26
101/2.73 x 10-1/2.65
(2.03
_
1.35
1016.31 x 102/1.17
—
9.5
1021.76 % 10-2/4.61
10-2!8.83 X 10-3/2.51
10-213.59 % 10-811.39
—
|9.96
—
(6.37
—
{5.06
107°/1.66 x 1072/4.02
1077|6.28 x 10-4
18.60 x 10-6
10-6
_
10-6
_
13.50 x 10-8
<
&
&
x
x
x
X
X
%
x
x
x
x
A22D
1072.58
1072.12
10-2}1.70
10-1/1.19
10719.57
1072|8.43
1072|3.13
1077|1.82
10-2|1.04
10-817.23
107*/4.40
10-312.39
10-211.75
x
x
«
*
x
x
X
x
x
x
x
x
X
1071
10-1
1071
1072
107
1072
107
1072
1072
10-3
1073
10-3
1073
stable barium level of 10mg/ml of solution. The in-
jection materials were neutralized with NaOH immediately before injection. The age and weight of each dog
at the time of injection, the quantity of %Ba injected,
and the time of sacrifice are listed in Table 7
Samples of venous blood were obtained at frequent
intervals on the day of injection and periodically
RETENTION oF Barium TRACER
0.153] 0.201
| 0.157) 0.303
injection
300
314
0.747] 0.680
3
4
5
G
7
20
27
34
41
48
83
189
188
Mi8
454
693°
6.1
10.0
A22B} A22C|A22D|
2
| mey of
ager
7.2kg
10.1 kg
Fractional retention
after
1
Sacrifice
time, days
from
9.25 yr
9.5 yr
Days
0
13Ba
+e
injected,
6.5 yr
TABLE 8.
injection]
Weich
eight at
injection, kg
8m
=4 yr
156
ing its f
(1966).
iduced
‘
mycin
IngEcTION oF Dogs witH Ba
TABLE 9.
0.531
0.458
0.382
0.334
0.305
thereafter for plasma clearance studies. Separate urine
and fecal samples were collected from each animal on
the days indicated in Table 10. No fecal or blood sam-
ples were collected from Dog 156.
Preparations of samples and analyses were as follows:
Whole-Body Retention
The body burdens of the two long-term retention
animals were measured in a steel room of the Division
of Biology and Medicine by placing a 5” x 4” Nal (TI)
crystal, connected to a multichannel analyzer, in a
reproducible position with respect to each dog. Immediately after the intravenous injections of the iso-
tope, each animal was counted so that the original
count included all of the injected activity. All subsequent counts were expressed as a fraction of the origi-
nal count. Also, for calibration purposes, an aliquot
of the original injection solution, sealed in a glass
vial, was counted in a reproducible position immediately after each dog was counted. The retention, ex-
pressed as percent of injected dose per gram of total
skeletal calcium, and the plasma specific activity, expressed as percent of injected dose per milligram of
plasma calcium, are tabulated in Tables 8 and 9 and