305
INFANTS AND THE EFFECTS OF GELATIN
SUPPLE-MENTATION
WITH
AND
WITHOUT
VITAMIN
B12
AND AUREOMYCIN
By
ROBERT KAYE, M.D.,#{176}RONALDH.
CAUCHEY, M.B.,M.R.C.P.,f
AND WALLACE W. MCCRORY, M.D.
Philadelp!iia, Pennsylvania
I
N TIlE COURSE of expermients designed to determine whether or not protein ana-bolic effects of vitamin B1, could bedem-onstrated in infants, a group of three
sub-jects were submitted to an experimental
(liet vhich contained a quantity of nitrogen
a))rOxiniately one-fifth of that usually given
to infants. Tile subjects who were male
infants were able to come into nitrogen
equilibrium on this regimen which provided a nitrogen intake of approximately 0.1 gram/kg/day.’
Inadequate protein nutrition is
wide-spread among children in some parts of the
WI It may occur protractedly as a
con-sequence of poverty, ignorance and famine, or more transiently with illness which
inter-feres with the ingestion or utilization of a
normal dietary. The experimental conditions
to be described created a situation of
pro-tein undernutrition which resembled to a
certain extent spontaneously occurring
“pro-tein starvation,” and also afforded an
op-portunity for evaluating, in infants, a recent
modification in the concept of the
nutri-tional role of the so-called non-essential
amino acids.
Since the definition by Rose3 of the 10
From The Children’s Hospital of Philadelphia,
and The Department of Pediatrics, School of
Medicine, University of Pennsylvania,
Philadel-phia, Pennsylvania.
This work was supported by grants from Lederle
Laboratories and the Knox Gelatine Company, and
was reported in part at the sixty-third annual
meet-ing of the American Pediatric Society, May 6-8,
1953, Atlantic City, New Jersey.
* Address: 1740 Bainbridge, Philadelphia 46,
Pennsylvania.
f Research Fellow, Auckland, New Zealand.
(Received for pul)lication March 5, 1954.)
essential amino acids required for normal
growth in the rat, there has been a natural
tendency to minimize the role of the non-essential amino acids in nutrition. Recently,
he has shown that the growth rate achieved
by his experimental animals, who received
the 10 essential amino acids as the sole
source of nitrogen, was only about 75% of
that which can be achieved by present day
rations.4 A series of experiments have clearly
shown that the addition of non-essential
amino acids to a basal ration consisting of
the ten essential amino acids results in an
improved growth rate. Results of this type
have been obtained with supplements of
glutamic the unnatural “d” forms of the essential amino acids,3 ammonium
cit-rate,6’7 glycine,7 urea, tyrosine,TM prolin&’ and a mixture of 19 amino acids. In
addi-tion, it has been shown in the rat that a diet
consisting of the 10 essential amino acids
supplemented by low levels of casein to the
extent that the combined total of essential
amino acids equalled the minimal amounts
suggested by Rose yields superior growth
to a mixture containing the same quantity
of essential nitrogen alone.10 Of perhaps
greater interest, was the finding that
in-creasing the essential amino acid nitrogen
to the extent of equalling the combined
total of essential plus non-essential amino
acid nitrogen fed in the above cited
experi-ment, failed to improve the growth rate
beyond that obtained with minimum
quan-tities of the essentials alone.’0 This experi-ment indicates a specific need for some
ni-trogen in the form of non-essential amino
acids. A similar need has been shown in the
mous&1 and dog.’2
al-Subject
%
Composition of Diet % of Calories From (‘als PerKg per Day
Prot. (‘arbohyd. Fat Prot. Carbohyd. Fat
4 .4
5 .4
6 .4
7 .3
8 .5
Average .4
9.7 3.9
9.() 3.7
7.6 3.1
8.9 3.6
9.5 3.8
8.9 3.6
2.1 51.4
2.2 50.8
2.7 50.7
1.7 51.4
2.7 51.2
2.3 51.1
46.5
47.0
46.6 46.8
46.1
46.6
103 115
101
119
99 107
*
Synthetic Milk Adapted-Wyeth, Inc.TABLE I
DETAILS OF INTAKE, Low PROTEIN REGIMEN
though growth may occur in the rat with a
mixture of 10 essential amino acids and
nitrogen equilibrium may be maintained in
the human adult with eight amino acids,13
all of the known amino acids are present in
the animal body. The conversion of essential
to non-essential amino acid components of
tissues requires energy. The rate at which
this conversion takes place may be
made-quate for rapid growth of the animal as a
whole or for repair following various
trau-714
The plan in the present experiments is to
determine the extent to which nitrogen from
gelatin can be retained by infants when
used as a supplement to a diet which barely
sustains nitrogen equilibrium. Gelatin is
completely lacking in the essential amino
acid tryptophane, and contains a high
percentage of glycine (26.6%).’ In
addi-tion, the effect of vitamin B,2 and
aureo-mycin on the retention of nitrogen
dur-ing gelatin supplementation is
evalu-ated. These agents were employed because
they have been shown to exert growth
effects in animals.1620 In addition, there is
some evidence that vitamin B12 exerts
growth promoting effects in malnourished
children.l23 Vitamin B,, exerts a sparing
effect on methyl donors,’4 and enhances the
rate of incorporation of glycine-nitrogen
into the liver of deficient rats.”
MATERIALS AND METHODS
The subjects were studied in a metabolic
ward and were given 24 hour nursing
super-vision. Feeding techniques, collection of sped-mens and analytic methods have been previ-ously described.’
The low protein diets were made from small
amounts of S. M. A.#{174}* supplemented with
dextrose and olive oil to provide adequate calories. The details of the caloric intake,
dis-tribution of calories and composition of the diet are given in Table I for the low protein
sub-jects. The average nitrogen intake was .098
gram/kg/day (Table II), and the average
caloric intake was 107 cal/kg/day. The
per-centage of the calories derived from protein
was 2.3, from carbohydrate, 51.1 and from fat, 46.6.
A diet of similar composition was used in
the control periods before the gelatin feeding
experiment. The diet was then supplemented
with gelatine so as to approximately double the
nitrogen intake. Gelatin was substituted
isoca-lorically for carbohydrate. During the period of
gelatin supplementation, the percentage of the
calories derived from protein was 4.0% and
4.8% for subjects 7 and 8 respectively (Table
III).
All patients received the following vitamin
supplement daily: vitamin A, 7,500 units;
vita-min D, 1,250 units; vitamin C, 50 mgm.;
thiamine, 10 mgm.; riboflavin, 2 mgm.;
pyri-doxine, 5 mgm.; nicotinamide, 50 mgm., and
pantothenic acid, 10 mgm.
The subjects of the low protein feeding
ex-periment were five male infants aged four to 12 months, whose weights varied between 4.3 and
8.2 kg., and averaging 8.6 months and 6.2 kg.
Two of these subjects, aged four and 12 months
re-TABLE II
StmnuIY OF BALANCE DATA
(GMS/KG/DAY)
Subject
Nitrogen
Weight Days on
Intake Urine Stool Balance Changes Balance
Low Protrin Group
4
6
7
8
Average
.07 .06 .03 -0.02 2.5 10
11 .08 .02 0.01 1.9 12
11 .07 .02 0.02 1.7 12
.10 .09 .03 -0.02 -1.5 12
.10 .07 .03 .00 .5 12
.098 .074 .026 -0.002 1.0 11.6
ceived gelatin supplements in additional meta-bolic periods. All of the subjeets were clinically undernourished.
Following periods of adjustment to the low
proteitl feeding of at least four days, the five low protein feeding patients were studied for
balance periods of 12 days duration with the
exception of subject 4 whose study period
was 10 days. Two of these subjects, 7 and 8,
were studied for additional periods of 12 days
in which the nitrogen intake was doubled with
gelatin, and a further period of 12 days in
which gelatin was continued and vitamin
B12,
300tg/day and aureomycin, 200-300 mgm./
day were given. Studies on subjects 4, 5, and
6 in regard to the effects of vitamin B,, and
aureomycin on nitrogen retention have been previously reported.’
RESULTS
Balance data for the low protein fed
sub-jects are averaged in Table II, and given
for the individual subjects in Table IV, and
graphically illustrated in Chart I. Chart I
shows that the average nitrogen intake of
the five subjects was 98 mgm./kg./day, and
the average retention was -2.0 mgm./kg.
/day or an approximate state of nitrogen
equilibrium for the group as a whole. There
were two subjects in the group in negative
nitrogen balance, two in positive balance
and one in nitrogen equilibrium. The two
subjects, 5 and 6, who received nitrogen
intakes above 100 mgm./kg./day, were in
positive nitrogen balance. Intakes of
100
mgm. N/kg./day resulted in one instance
of nitrogen equilibrium
(
subject 8) and oneof negative nitrogen balance
(
subject 7). Anitrogen intake of 70 mgm./kg./day in
sub-ject 4, the lowest in the group, and the only
instance of an intake below 100 mgm./kg./
day resulted in a negative nitrogen balance.
All subjects except subject 7 showed small
weight gains. The average weight gain for
TABLE III
I)ETAas OF INTAKE, GELATIN SUPPLEMENTED FEEDING
Subject am!
Regimen
%
Composition of Diet%
of Calories FromCalories Per Kg Per Day
Prot. Carbohyd. Fat Prot. Carbohyd. Fat
7 Control
Gelatin
.3 8.9 3.6
.7 8.5 3.6
1.7 51.4 46.8
4.0 49.1 46.8
119
-
1218 Control
Gelatin
.5 9.5 3.8
.9 9.1 3.8
2.7 51.2 46.1
4.8 49.0 46.1
99
Subject Period
uhj. IV I
Age 12 nms. 10 Wt. 7.2 Kg. I)ays
Subj. \ I
#{149}tge4moo. 12
Wt. 4.7 Kg. l)ays
subs. VI I
Age 11 nms. 12
Wt. 6.5 Kg. Days
SLll)j.VII I
Age 4moo. 12
Vt. 4.3 Kg. I)ays
Ul)j. III I
Age 12moo. 12
Wt. 8.2 Kg. I)ays
.9
.4
.2
.3
(‘1 Weight Change (Gm.)
nLEq./ mEq./ Per /Kg / Period Kg/Day Period Day
37.0 .5 180 2.5
2.6 .1
3.0 .1
3.14 .3
84.9
45.1 .8 105 1.9
18.4 .3
4.2 .1
22.5 .4
49.9
57.6 .7 135 1.7
27.5 .3
1.5 .1
28.6 .3
49.6
38.3 .7 -75 -1.5
5.0 .1
6.4 .1
26.9 .5
70.2
68.4 .7 45 .5
14.4 .1
6.0 .1
48.0 .5
70.2
.9 .2
.3 .4
tile group as a whole was 1.0 gram/kg./day (Table II).
Both subjects given gelatin supplements
showed significant increases in nitrogen
re-tention (Table V, Chart II). In the case of
subject 7, the addition of 120 mgm. N/kg.!
day derived from gelatin resulted in an
increase in nitrogen retention of 50 mgm./
kg./day. Subject 8, whose nitrogen intake
was increased 120 mgm./kg./day by
gela-tiii supplementation, retained an additional
60 mgm. N/kg./day over the control level.
The increased nitrogen retentions in
as-sociation with gelatin feeding in subjects 7 and 8, were 23 and 27% of the nitrogen
intakes during the periods of
supplementa-tion. Changes of this magnitude are
ade-quate evidence of retention of a significant
portion of the nitrogen contained in the
gelatin supplement.
No significant alteration in nitrogen
re-tentlon occurred in either subject as a result
of the addition of vitamin B,, and
aureo-mycin to the gelatin supplemented regimen
(Table V, Chart II).
In
both
subjects,
the
increased
retention
of nitrogen which accompanied gelatin
supplementation was associated with an
in-creased rate of weight gain. In subject 7,
the weight gain was approximately twice
the theoretical gain to be expected from the
observed nitrogen retention, while that of
subject 8 was in good agreement
(
106% oftheoretical).26
The subjects on gelatin supplements
showed increased retention of the
electro-lytes Na, K, and Cl, accompanying tile
ifl-crements in weight and nitrogen retention,
which, however, were in excess of the
theo-retical retentions based on observed weight
gains. Interpretation of these discrepancies is difficult in the absence of measurements
of sweat and insensible electrolyte losses,
which may assume importance under the
circumstances of the low intakes given to
these subjects.
TABLE IV
BALANCE DATA Low PROTEIN REGIMEN
N Na
Grarns/ Grams! mEq./ mEq./ Period Kg/Day Period Kg/Day
mt. 5.25 .07 57.0 .8
Urine 4.51 .06 8.7 .1
‘t(X)l 1.96 .03 16.0 .2
Ital. - 1.22 -0.02 32.3 .5
#{182}Ret. -23.20 56.7
Int. 5.93 .11 47.3 .8
Urine 4.69 .08 24.0 .4
&‘t(M)l .88 .02 6.3 .1
Hal. .30 .01 17.0 .3
#{182}Ret. 6.10 35.9
mt. 8.38 .11 69.6 .9
Urine 5.66 .07 42.4 .5
1.47 .02 5.0 .1
Hal. 1.25 .02 22.2 .3
% Ret. 14.90 31.9
mt. 5.09 .10 47.4 .9
Urine 4.72 .09 8.9 .2
tX)l 1.73 .03 27.3 .5
Hal. - 1.36 -.02 11.2 .2
Ret. -26.70 23.6
Int. 9.79 .10 77.0 .8
Urine 6.47 .07 30.3 .3
3.18 .03 30.2 .3
Hal. .14 .00 16.5 .2
Ret. 1.40 21.4
K
mEq./ mEq./ Period Kg/Day
46.7 .6
11.6 .2
11.1 .2
24.0 .2
51.4
51.6 .9 21.1 .4
12.4 .2
18.1 .3
35. 1
72.7 28.4
12.5
31.8 43.7
47.5 .9
14.2 .3
24.9 .5
8.4 .1
17.7
84.2
23.8 34.7
4 5
h2mo 4mo
72kg 47kg
I 10
Subject 7
4mo. 43 Kg.
Subject 8
I2mo. 8.2Kg Subjects
6
lImo 65 kg
110
I
7 8 Average
4mo l2mo 86mo
43kg 82kg 62kg
100100
7
/
7
ifi
I
2 2 2
EURINE STOOL
7lz7lAL,J
-2
2 116
.
BALANCE0 2 24 36
0 6 6
0 0 300
0 0 300
It is imnderstood, of course, that nitrogen equilibrium is an unphysiologic nutritional
state for young infants who should be in
strongly positive nitrogen balance. It was
felt that the i)rief periods of protein
under-nutrition
(
111) to 40 days) to which thesein-fants were subjected, would not be respon-Sii)lC for an’ subsequent disability. Keys27 has state(l ill regard to the effects on chil-(1ren of living under tile nutritional
condi-tiOllS attcn(lant upon war and economic
depression:
“The rapid recovers’ of the body size deficits
of 1917-2() led \Volff to take to task those who
were bewailing degeneration and decay of
civilization 11S a result of the depression of the
19:30s. Tile retarded children in Holland made
NITROGEN BALANCE ON
LOW
PROTEIN
INTAKE
hO
00
90
80
70
60
0
zo 40
-
30 20ho 7
0---.----10 2
-20 -20
-30
DAYS ON 0
BALANCE
CIJAIIT I. The (lata are charted in mgnl. N/kg/
(l11V. The intake is indicated lw the height of the
column, urine 1111(1 stool excretions are measured
(lo5vnsvar(l from tIle top of the intake colunin and are in(licatc(1 l)\’ clear and cross-hatched areas
re.spcctist.lv. A psitise l)alance appears 115 1 black
area al)oyc. ,lIld a negative balance as an extension of tile fecal excretion area below the base line. The average for the group is indicated on the right of
the chart.
DIscussIoN
BALANCE
STU DY
-LOW
PROTEI N
GELATIN
SUPPLEMENTATION
20
.l6
>. .12
.08
2:: 04
(%J
0Z .O2
05
Z 0
>‘
ci 0,. Q5.
00
C
11.01
: o.sI
U
0
.- . --.
ii
DAYS ON 12 24 36
BALANCE
GELATIN 0 35 35
GMS /DAY
VITAMIN B 0 0 300
g/DAY
AtJREOMYCIN 0 0 200
MGM/DAY
j...
,___JI1
CHART II. The data are charted as in Chart I,
for N, Na, K, and Cl. Tile duration of the balance
periods, weight gains and the details of
stipple-mentation are indicated at the bottom of the chart.
rapid recoveries when liberated and sent to Australia for rehabilitation. From past experi-ence it can be safely assumed that the food
crises of the 1940s in many parts of the world,
if they are not of too long duration, xviii
prob-ably have no permanent harmful effect on the generation of growing children.”
It is interesting to find that our subjects
were able to achieve nitrogen equilibrium
on an intake which is approximately
one-fifth of that customarily given to infants.
The subjects were permitted a period of
four to five days in order to adjust to the
transition from an average to a low protein
.
Regimen and ..
Subj t I . Period . Grams/ Grams/ Period Kg/Day Na mEq./ mEq./ Period Kg/Day K mEq./ mEq./ Period Kg/Day Cl mEg.! mEq./ Period Kg/Day Weight Change (Gm.) Per 1Kg.! Period Day Subj. VIIAge 4 taos. \\t. 4.30 Kg.
LowProtein I 12 Days Int. Urine Stool Hal. %Ret. 5.09 4.72 1.73 - 1.36 -26.70 .10 .09 .03 -.02 47.4 8.9 27.3 11.2 23.6 .9 .2 .5 .2 47.5 14.2 24.9 8.4 17.7 .9 .3 .5 .1 38.3 5.0 6.4 26.9 70.2 .7 .1 .1 .5
- 75 -1.5
LowProtein +Gelatin Wt.4.23Kg. Low Protein +Gelatin +Vitamin B12 +Aureomycin
Svt.4.35 Kg.
Subj. VIII
Agel2mos.
55.t. 8.20 Kg.
I.ow Protein II 12 I)ays III 12 Days I 12 I)ayo Int. Urine Stool Hal. %Ret. Int. Urine Stool Hal. () Ret. Int. Urine Stool Hal. %Ret. 11.05 8.12 1.68 1.25 11.30 11.45 9.20 1.68 .57 5.00 9.79 6.47 3.18 .14 1.40 .22 .16 .03 .03 42.9 9.9 8.0 25.0 58.3 .8 .2 .1 .5 46.7 10.1 13.5 23.1 49.5 .9 .2 .3 .4 38.5 1.6 2.9 34.0 88.3 .7 .1 .1 .5 +120 2.4 4.0 .22 .18 .03 .01 .10 .07 .03 .00 44.1 17.3 10.0 16.8 38.1 .8 .3 .2 .3 49.5 15.5 11.3 22.7 45.8 .9 .3 .2 .4 49.1 3.0 3.8 42.3 86.1 .9 .1 .1 .7 +210 77.0 30.3 30.2 16.5 21.4 .8 .3 .3 .2 84.2 23.8 34.7 25.7 30.5 .9 .2 .3 .4 68.4 14.4 6.0 48.0 70.2 .7 .1 .1 .5 45 .5 LowProtein +Gelatin Wt.8.24Kg. II 12 1)ayo Int. Urine Stool Hal. #{182};2Ret. 21.54 12.55 2.70 6.29 29.20 .22 .13 .03 .00
,
74.6 32.2 6.7 35.7 47.9 .8 .3 .1 .4 90.5 20.7 12.8 57.0 63.0 .9 .2 .1 .6 74.3 10.4 1.4 62.5 84.1 .8 .1 .1 .6 315 3.2Low Protein III +Gelatin 12
+Vitamin I3 I)ayo
+Aureomycin
\Vt. 8.55 Kg.
,
mt. Urine Stool Ilal. 7c.Ret. 21.78 10.66 2.87 8.25 37.90 .21 .10 .03 .08 75.0 32.4 4.6 38.0 50.7 .7 93.1 .3 21.9 .1 9.4 .3 61.8 66.4 .9 .2 .1 .6 89.0 18.2 2.5 68.3 76.7 .9 .2 .1 .6 315 3.1 310 TABLE V
BALANCE DATA GELATIN SUPPLEMENTED SUBJECTS
adjustment, as judged by a fall in urinary
nitrogen excretion to a fairly stable
mini-mum level, was accomplished in four to six
days. It is possible that our subjects would
have been able to come into nitrogen
equi-librium, after a further period of
adjust-ment, on intakes lower than those offered
in our investigation. Siven in 190028 ad-ministered to a 60 kg. man, who normally
ingested a diet containing 16 grams of
nitro-gen, successively reduced nitrogen intakes
of 12.7, 10.4, 8.7, 6.3, and 4.5 grams/day.
The diets yielded about 2400 calories, and
the subject was able to achieve nitrogen
equilibrium at all levels of intake after three
to four days of adjustment. Bartlett,’9 found
the nitrogen requirements for equilibrium
of diabetic children to approximate that of
our infants. Adults on a diet in which the
source of protein was cow’s milk were
main-tamed in balance on an intake of about 55
mgm. N/kg./day by Bricker et al.3#{176}
These findings serve to emphasize the
fact that in situations where it is difficult or
impossible to provide optimum nitrogen
intakes, the provision of sub-optimum
amounts can be expected to produce some
degree of nitrogen retention or at least to
limit the magnitude of deficits. Siven’s work
seems especially important in this regard
because it shows the capacity of the
organ-ism to adjust the rate of nitrogen excretion
to the intake to the end that equilibrium
than one-third the optimum for adults. Our infant subjects achieved nitrogen equilib-rium on an intake of about
100
mgm./kg./day. This amount can be provided by a
plasma infusion of approximately 10 cc. /kg./day.
A recent report of Cox et al.,3’ is
interest-ing in this regard. They showed that rats
were able to retain nitrogen on a diet which
was calorically inadequate. They point out that although carbohydrate and fat do spare
protein and, therefore, the provision of
ade-quate calories derived from these sources
is desirable in order to secure maximal
uti-lization of dietary nitrogen, that this is not
an “all or none” phenomenon. Too often do
we administer parenteral feedings of
glu-cose alone, because of the assumption that
unless full caloric requirements are
pro-vided administered protein will be
com-pletely burned to decrease the caloric
deficit.
The retention of a considerable portion
of the nitrogen derived from gelatin by
both subjects to whom it was administered
is in harmony with the observations on the
nutritional role of the non-essential amino
acids cited in the introduction to this paper.
Subjects 7 and 8 were initially receiving
nitrogen intakes of 100 mgm./kg./day.
Gel-atm supplementation to the extent of 120
mgm. N/kg/day resulted in increased re-tentions of 50 and 60 mgm. N/kg./day
respectively. This degree of retention is in
agreement with the results of Petrunkina
who found that children retained
approxi-mately
40
of nitrogen supplements of 100mgm./kg./day.3’ The ability of infants to
retain a considerable portion of the nitrogen
derived from an incomplete protein source
when it is used to supplement a dietary
containing minimum quantities of good
quality protein is of theoretical interest
but
should not be interpreted as an indication
for the use of protein supplements of poor
biological quality when more complete
pro-teins are available. It should also be
em-phasized that the studies reported here
employing a basal diet of high quality
pro-tein do not demonstrate that gelatin
sup-plementation would improve the nutritional
value of the poor quality diets of Kwashi-orkor cases.
The data show no increase in nitrogen
retention following the addition of vitamin
B,, and aureomycin to the gelatin
supple-mented regimen. This is in accord with our
previously reported findings in infants
main-tamed on constant diets high and low in nitrogen.1
SUMMARY
1. A group of five male infants who
re-ceived an average nitrogen intake of 98
mgm./kg./day, derived from cow’s milk
protein, retained an average of -2.0 mgm./
kg./day. Small positive balances were
achieved at intakes of 110 mgm./kg./day in
two subjects. An intake of 100 mgm./kg./
day in two subjects resulted in one instance
of nitrogen equilibrium and one of negative
nitrogen balance. In the subject given the
lowest nitrogen intake, 70 mgm./kg./day a
negative nitrogen balance was encountered.
These data suggest that the lower limit of
nitrogen intake for equilibrium in infants
under the experimental conditions reported
here is approximately 110 mgm./kg./day.
2. Two of these subjects received
gela-tin supplements providing 120 mgm. N!
kg./day, and responded with increased
ni-trogen retentions of 50 and 60 mgm. N!
kg./day.
3. Retention of the gelatin supplements
was not further increased in either subject
by the administration of 300 g. of vitamin
B12, and 200-300 mgm. of aureomycin daily.
4. The provision of a protein which does
not contain all of the essential amino acids,
as a supplement to protein of good
biologi-cal quality permits real augmentation of
nitrogen retention.
5. Certain implications of the data in
regard to the nutritional value of
sub-opti-ma! intakes of nitrogen and total calories
have been discussed.
The authors wish to acknowledge the
as-sistance of Mrs. Dorothy V. Murphy who
supervised the patients in the metabolic
REFERENCES
1. Kaye, R., Caughey, R. H., and McCrory,
w. w.
:Effects of vitamin B12 andaure-omycm on nitrogen retention in infants.
PEDIATRICS, 13:462, 1954.
2. Trowell, H. C. : Malignant malnutrition (Ksvashiorkor). Tr. Roy. Soc. Trop. Med. and Hyg., 42:417, 1949.
3.
Rose, W. C. : The nutritive sigmficance ofthe amino acids. Physiol. Rev., 18:109, 1938.
4. Rose, W. C., Oesterling, M. Jane, and
Wo-mack, Madelyn : Comparative growth
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J.
Biol. Chem., 176:753, 1948. 5. Anderson,J.
T., and Nasset, E. S. :Nitro-gen balance index and specific dynamic action in rats receiving amino acid mix-tures low in isoleucine, methionine or valine.
J.
Nutrition, 36:703, 1948.6.
Lardy, H. A., and Feldott, Gladys: The net utilization of ammonium nitrogen bygrowing rat.
J.
Biol. Chem., 179:509, 1949.7. Rose, W. C., Smith, L. C., Womack,
Madelyn, and Shane, M. : The
utiliza-tion of ammonium salts, urea and
cer-taill other compounds in the synthesis of non-essential amino acids in vivo.
J.
Biol. Chem., 181:307, 1949.
8. Ramassarma, G. B., Henderson, L. M., and
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SPANISH ABSTRACT
Balance de Nitr#{243}geno con Ingestiones Bajas de Nitr#{244}geno y Efecto del
Agregado de Gelatina con y sin Vitamina B12 y Aureomicina
El objeto de este trabajo es determinar el
grado de retenci#{243}n de nitr#{243}geno de la gelatina
(1t10 se proporciona a lactantes cuando se emplea como suplemento a una dieta que
apenas mantiene el equilibrio nitrogenado; Ia gelatina carece del amino #{225}cidoesencial
trip-tofano pero en cambio contiene un alto
por-centaje de giicina. Se ha sostenido que Ia vitamina B12 ejerce acci#{243}n de crecimiento en
los ni#{241}osdesnutridos, asI como que tanto ella
como Ia aureomicina son factores de crecimiento
en animales; por lo tanto se emplearon tambi#{233}n
para valorar su efecto sobre Ia retenci#{243}n de
nitr#{243}geno al suplementar la dieta con la
gela-tina.
Se estudiaron 5 ninos del sexo masculino en una sala metab#{243}lica con vigilancia continua
durante las 24 horas. Previamente se han
des-crito las t#{233}cnicas de alimentaci#{243}n, de
recolec-ci#{243}nde niuestras
y
de los m#{233}todosanalIticos. Las dietas hipoproteicas se hicieron a base deS.M.A. suplementadas con dextrosa y aceite de
olivo para proporcionar un nmimero adecuado
de calorias; los ni#{241}osrecibieron un promedio de 98 mgrs. de nitr#{243}geno por kilo y por dia. La dieta fu#{233}despu#{233}s agregada de gelatina para
doblar aproximadamente la ingestion
nitro-genada. Todos los pacientes recibieron diana-mente 7500 unidades de vitamina A, 1250
unidades de vitamina B, 50 mgrs. de vitamina
C, 10
miligramos de tiamina, 2 mgrs. denibo-flavina, 5 mgrs. de pinidoxina, 50 de nicotina-mida y 10 de #{225}cidopantot#{233}nico. Los ni#{241}oscon
regimen hipoproteico tenIan de 4 a 12 meses de
edad y de 4.3 a 8.2 kilogramos de peso, con
un pnomedio de 8.6 meses de edad y 6.2
kilo-gramos de peso; dos de estos ninos fueron de 4 a 12 meses de edad y tuvienon 4.3 y 8.2 kilos
de peso, respectivamente, y recibieron el
su-plemento de gelatina en penlodos metabdiicos
adicionales. El primer perIodo de estudio
durO 12 dIas, excepto con el ni#{241}o#4 que fu#{233} de 10 dIas; los ni#{241}os7 y 8 se estudiaron por
penlodos adicionales de 12 dIas con ingestiOn doble de nitrOgeno a base de gelatina y un
penlodo m#{225}sde 12 dIas con gelatina m#{225}s
vita-mina B,,, 300 mgrs. por dIa, y aureomicina,
200 a 300 miligramos por dIa (Los estudios de
los casos 4, 5 y 6 fueron ya publicados).
Los ni#{241}osque recibienon un pnomedio de
98 mgns. de nitrOgeno por kilo y por dIa
ne-tuvieron Un promedio de -2 mgrs. por kilo y
por dIa; el equilibrio positivo se obtuvo cuando
se les diO ingesta de 1 10 mgrs. pon kilo y por
dIa; otno presentO balance equilibrado de
iii-trOgeno y un cuanto negativo, ambos con 100
mgrs. pon kilo y por dIa; el caso que necibi#{243}la ingestiOn nitrogenada m#{225}sbaja, 70 mgrs. por
kilo y pon dIa, presentO balance nitrogenado
negativo. Estos datos sugieren que el Ilmite
inferior de ingestiOn de nitnOgeno pana el
ba-lance positivo en los ni#{241}osen las condiciones
anotadas es de aproximadamente 1 10 mgns. por
kilo y por dIa.
Los dos ni#{241}ossuplementados con gelatina
recibieron 120 mgrs. de nitndgeno por kilo y
por dIa; mostnaron retenciones de 50 a 60
mgrs. de nitndgeno por kilo y por dIa. No se obsenvd mayor netencidn en los ni#{241}osagregados de gelatina en su dieta cuando se les administnO
Ia vitamina B,2 y la aureomicina a las dosis
indicadas.
La administnaciOn de una proteIna carente
de algunos amino#{225}cidos esenciales como suple-mento a proteInas de alto valor biolOgico pro-voca un aumento real de netenciOn nitnogenada. Esta capacidad de los ni#{241}osdebe aceptanse
como de inten#{233}steOrico y de ninguna manera
intenpnetarse como indicacidn de suplementos
proteicos de pobre valor biolOgico cuando se
disponga de proteinas m#{225}scompletas. Los
autores tambi#{233}n recaican que sus estudios con
dietas b#{225}sicasde protelnas de alto valor no
demuestnan que el agregado de gelatmna pudiera
