B. N. MAJUMDAR, S. N. RAY AND K. C.
SEN
99
rats the concentration of fluorine in bone in rela-
tion to age followed a logarithmic curve. They,
however, did not analyse the pelvic bones and their
conclusions were based on analysis of ribs and
femurs. When it is remembered that these samples
have been obtained from various localities from
animals obviously on different types of feeds,
it appears that, up to a certain maximum limit,
the deposition of fluorine in the bones is inde-
pendent of the amount ingested in the diet.
Only when this limit is exceeded is fluorine
apt to be retained in the bones in greater quanti-
ties. This point will be dealt with in a later part
of the paper.
Fluorine content of the blood of normal animals
Very little work has been done regarding the
fluorine content of the blood. Gautier and
Clausman [1913], whose investigations were very
comprehensive, found about 0.46 mg. of fluorine
per 100 gm. of fresh blood in human beings.
Lang [1928] reported a value as high as 0.75 mg.
fluorine per 100 c.c. blood in rabbits. The latter
worker in collaboration with Stuber [Stuber
and Lang, 1928, 1929] formulated a theory that
the fluorine content of the blood determined its
coagulation time and that the blood of haemophiles
contained 4-5 times more fluorine than normal
blood. This assertion could not, however, be
corroborated by Hoff and May [1930] or by
Feissly, Fried and Oehrli [1931], who could only
find traces of fluorine in the blood of both normals
and haemophiles in amounts less than 0.5—1 mg.
per 100 c.c. blood. Shortt et al. [1937] found a
large percentage of fluorine in the blood of patients
suffering from chronic fluorosis, but they them-
selves did not place much confidence in their own
figures as they were uncertain of their analytical
methods. Du Toit, Smuts and Malan [1937]
found a concentration of 0.17 mg. of fluorine per
100 c.c. blood in cows in a low fluorine ration,
whereas the corresponding figure for animals on a
fluorine-rich feed was 0.6 mg. per 100 c.c. Ramiah
[1940-41], working on the fluorine content of the
blood of bullocks on both fluorine low and rich
rations, found the concentrations in the various
groups to differ little from each other and the
values to be very high (1-2 mg. per 100 c.c. blood).
Samples of oxalated blood from normal animals
of different ages were collected and examined
by our new method. The results are given in
Table III. It will be seen that, in contrast with
that in the bones and teeth, the concentration of
fluorine in the blood is independent of the age
factor. It will be shown later that the blood
fluorine concentration can be raised only by
feeding excessive amounts of fluorine.
TABLE III
Concentration of fluorine in the blood of normal
animals
Group.
Heifer
calves (below 3
years)
Lactating cows (3—7 yrs.)
Lactating cows (over 7
years)
Lactating
cows (preg-
nant)*
Non-lactating cows(preg¬
nant)*
Bulls*
.
.
.
.
Hill bulls (all ages)
No. of
samples
examined.
4
6
6
4
4
3
23
Range of
fluorine
mg./100c.c.
blood
0.08-0.11
0.08-0.13
0.08-0.14
...
...
...
0.08-0.23
Avergae
fluorine
content
mg./100c.c.
blood
0.10
0.11
0.13
0.14
0.16
0.13
0.13
*Pooled samples of blood were examined.
It will be noted that our figures for the flourine
concentration in normal bovine blood are similar
to those of Du Toit et al. [1937].
Experimental observations
Adult healthy hill bulls aged 3—5 years and
weighing 250—300 lb. were chosen, and were
divided into four groups, each group consisting of
three animals. All the animals received a ration
consisting of 6 lb. of wheat bhoosa and ¾—1 lb.
of a concentrate mixture composed of equal parts
of ground-nut cake and barley. The fluorine
intake through the basal diet was about 15 mg.
daily. The animals of the first group, henceforth
termed the control animals ', received the basal
ration alone. The animals of the second and third
groups received daily, in addition, 50 mg. and 500
mg. of fluorine respectively in the form of sodium
fluoride and thus consumed 65 mg. and 515 mg.
of fluorine per day per animal. These groups are
called the 'low fluorine' and 'high fluorine'
groups respectively. The NaF was dissolved in
water
and the
calculated amounts were
measured daily and added to the concentrate mix-
ture. The animals of the fourth group received,
in addition to the basal ration, 500 mg. of fluorine
plus 2 oz. of calcium phosphate daily. This
group is called the ' calcium ' group. Water
was given ad libitum to the animals.
The basal ration was selected in such a way as to
supply the animals with approximately the mini-
mum requirements for protein and energy pro-
duction. It was barely sufficient in calcium and
deficient in phosphorus. In other words, an