174
human beings have been derived chiefly from
parasites---chiefly worms. When necessary,
Serystoid” tablets (0.1 g, Sharp and Dohme)
three sources: (a) Extrapolation from experience
with Jaboratory animals, undependable at
best; (5) studies of the behavior of stable
strontium in normal man; [11-13] and (e) tracer
and/or gentim. violet capsules (4 gr, Lilly)
were administered until] very few worm eggs
usually neoplastic (14, 15]. For obvious reasons data on Sr® in normal human beings can
handled with the help of a veterinarian and a
dentist. Prior to use in an experiment, all
animals were maintained in the colony for a
conditioning period of 3 ta 6 months.
experiments with shorter-lived radioisotopes of
strontium in patients with advanced diseases,
be obtained only from accidental contamina-
tion such as that reported by Cowan ef al.
{14] and the exposure of the Marshallese during
Operation Castle (17-191.
Tt was believed that another primate, the
rhesus monkey, might provide valuable clues
to the behavior and effects of Sr” in man despite
the differences in life span—20 years vs. 65
years-~and diet-—~herbivorous vs. omnivorous.
Edington ef al. (20] reported that 0.5 mC/kilo
of S:™ was lethal to monkeys in 35 to 60 days.
Using microradiographic and autoradiographic
techniques, Jowsey e¢ al. [21] found that in the
tibiae of monkeys Sr was laid down quite
unevenly, and apparently only in areas of bone
growth.
This reportis a summaryof the data obtained
during the past 2% years in the course of a
series of investigations with Sr® in the rhesus
monkey (Macaca mulatta).
METHODS
General Care of the Animals
The animals used in these studies were adult,
adolescent, and infant rhesus monkeys of both
sexes, Adults and adolescents were maintained
on the diet shown in Appendix I unless otherwise specified. They were fed early each
morning; the entire daily ration was offered at
thal time. “Upon receipt, each animal was
tested for tuberculosis and X-rays were taken
for age determination.’ The TB tests were
repeated at least annually. All animals in the
colony were weighed once a month. Complete
blood counts were also taken monthly. Periodically the colony was checked for intestinal
' Tabulation of the bone growth date fs still incomplete.
could be foutid in three consecutive daily stool
samples.
Miscellaneous problems in eare were
Intravenous Studies
Breeding Experiments
To date Resy has been successfully mated
with Stupe and has berne three apparently
normal offspring. The first, Willic, was born
98 days after the mother received her Sr
injection, Betty was born 402 days postinjection, and Henry was born 840 days postinjection. Daily milk samples of 1,2 to 8.3 mi were
obtained from the mother with a breast pump
from the third to the sixth dey after the birth
of the second infant, Betty. The Sr™ levels of
the red blood cells and plasma of the mother
were obtained 30 days later.
All three infants
Three adults, Supe (a normal healthy male},
Tony (an older male with an “arthritislike’’
were removed from the mother at birth and
(a 3-months-pregnantfemale ?) were each given
35uC of carrier-free Sr® as the equilibrium
mixture of Sr®Y" and 135uC of high-specificactivity Ce* intravenously in isotonic sodium
are shown in Appendix II.
condition of the lower extremities), and Rosy
citrate?
One adolescent, Pat, received only
Sr®, 3 months after being placed on a lowcalcium diet (the standard diet without the
milk and vitamin supplements).
After injection of the radioisotopes all
animals were placed in metabolism cages, and
daily collections of urine and feces were made
for 10 days. After the initial 10-daycollection
period
the animals were returned to their
have been raised on formula by members of the
staff.
The formula and dietary supplements
A careful record
has been kept of the food intake, body weight,
and blood counts of the infants.
The Sr burdensof the first two infants were
checked when they were 3 months old by in
vivo counting of the Bremsstrahlung produced
by the Y™ beta particles with two 2-inch sodium
iodide seintilation counters. Bone biopsies
(caudal vertebrae) were obtained from Willie
and Betty at 20 and 10 months of age respectively. Fecal samples were obtained periodically from each animal for Sr® assay.
The youngest, Henry, was checked for Sr®
regular cages. Fecal samples were obtained
periodically without transfer af the animals
from their regular cages.
content 8 days after birth by the above-mentioned in vivo method. This animal has worn
plastic pants and a diaper (fig. 1) since he was
long-term study.
exereta, Pooled excreta were collected daily
from birth until age 36 days to establish the
rate of elimination of the Sr® acquired in utero.
When 36 days old he was put on a long-term
Stupe and Rosy were kept for breeding and
Pat was sacrificed 94 days
after injection, and Tony, 242 days after
injection, both with overdoses of nembutal.
Muscle was dissected from the various parts of
the skeleton, which were ashed individuallyfor
radioactive assay. Muscle and soft-tissue bal-
ance were also prepared for assay. Bone biopsy
samples were obtained from the two remaining
adults and one uninjected adolescent female by
amputation of two caudal vertebrae. The
operations were performed under aseptic conditions and were followed
antibiotics.
by a course of
2 Gestation period for this species is 6 months,
¢ Both isotopes were obtained fram Oak tidge National Laboratory
175
MUTABOLIC STUDIES WITH STRONTIUM-90
THE SHORTER-TERM BIOLOGICAL HAZARDS OF A FALLOUT FIELD
a few days old so as to facilitate collection of
low-level feeding program. For the past 5
months he has received daily in his first bottle
0.0043 pC of Sr® as the equilibrium mixture
except on weekends and holidays. Since the
iniliation of the feeding program, pooled daily
excreta have been collected, ashed, and assayed
for Sr®4 Retentinn has been measured by (a)
calculation from excretion data, (6) periodic in
vivo counting, and (¢) caudal vertebral biopsy.
enemies
Unfortunately, urine and feees are not readily separable,
Fraune 1.— Infant monkey with plastic pants and diaper,
Absorption and Retention in Adolescents
Six adolescent monkeys,’ two males and four
females, have received daily 0.0066 uC of Sr®
as the equilibrium mixture except on woekends and holidays since Tune 26, 1956. A
round slab of banana is scored with a knife,
and 0.1 ml of a dilute saline solution of Sr®
is spread over the scored portion. The “spiked”
banana is offered to cach animal at least 10
minutes before the rest of the day's ration is
presented.- So far, there have been few diffi-
culties in this feeding procedure because the
animals are hungry, and banana is their favorite
food. At the beginning of the feeding period
the animals were housed in metabolism cages
for collection of excreta.
The separation of
urine and feces is not complete because of the
semiliquid nature of the stools, particularly
after treatment for worms. Excreta are collected every other day and pooled on a weekly
the
basis for assay. Twelve weeks after
initiation of the feeding program three of the
2 Years.
5 Estimated age at fil lationof feeding program: