the basal heat production of the rhesus monkey (macaca mulatta)

THE BASAL HEAT PRODUCTION OF THE RHESUS
MONKEY (MACACA MULATTA)
NATHAN EAKIETEN «
Laboratory of Physiology, Tale University School of Medicine, New Haven
(Received for publication May 29, 1935)
The gaseous metabolism of the primates has only recently
been the subject of investigation. Botschkareff ('33) deter
mined the heat production of one macaque and three mandrills,
but he was unable to secure basal conditions during observa
tions. The only other published data are those of Bruhn
( '34), who studied the basal metabolic rate of various species
of primates including in his series four normal adolescent
rhesus monkeys (Macaca mulatta ). In view of the paucity of
information concerning the metabolism of the rhesus monkey
it has seemed worth while to record further studies on the
basal heat production in this form.
METHODS
Six female and five male monkeys were studied. They were
normal adolescent animals the weights of which varied from
2.7 to 3.6 kilos. The animals were generally fasted 18 to
24 hours prior to observation, but in one series the postabsorptive
period was lengthened to 36 hours.
The determinations were made in an open circuit system
modelled after the apparatus devised at the Carnegie Nutri
tion Laboratory at Boston (Carpenter and Fox, '31). The
animal, confined in a small cage, was placed in a chamber of
appropriate size through which outdoor air was circulated by
1When this work was done the author was a Porter Fellow of the American
Physiological Society. The research was aided by a grant from the research funds
of the Yale University School of Medicine. The author is at present in the
Physiology Department at Massachusetts State College, Amherst, Massachusetts.
THE JOURNAL OF NUTRITION, VOL. 10, NO. 4
357
Downloaded from
jn.nutrition.org
by guest on March 23, 2013

358 NATHAN RAKIETEN
a rotary blower. The outgoing air after passing through two
dry gas meters was collected for analysis by the Fox bag
method of aliquot sampling (Carpenter and Fox, '31). The
samples so obtained were stored in Benedict ( '27) respiration
pumps, and then analyzed in the Carpenter ('33) gas analysis
apparatus. An activity recorder modified from that described
by Benedict and Homans ('12) was used to register the ani
mal's movements. Usually aliquots from four to five 20-
minute periods were collected and the results of the two
periods which gave the best agreement were taken to denote
the animal's heat production. The lowest values were chosen
in every instance. An agreement of 6 per cent or less was
usually obtained for successive periods. Following the ex
periences of Bruhn ( '34) the determinations were made at
night to facilitate basal conditions.
The apparatus was tested intermittently during the investi
gation by burning alcohol in the chamber and by analyses of
outdoor air. The mean respiratory quotient for alcohol in
this series was 0.664 ±0.003, while the greatest variations
from the theoretical respiratory quotient of 0.667 were 0.674
and 0.658. The average results for the outdoor air analyses
were 0.032 for C02 and 20.942 for 02.
The surface area of the animals was calculated by the
method of Lee and Fox ( '33).
EESULTS AND DISCUSSION
The complete data obtained in these experiments are pre
sented in table 1. It was found that the average heat pro
duction of the eleven animals was 608 Cai. per square meter
per 24 hours. This is approximately 7 per cent lower than
the average figures given by Bruhn ( '34) for the four normal
animals studied by him. Eight of the eleven animals had
metabolic rates that ranged from 586 Cal. to 640 Gal. and the
remaining three, numbers 30, 4 and 37, gave values, respec
tively, of 543, 543 and 709 Cal.
The wide divergences from the mean of these three animals
were undoubtedly due to their distinctive metabolic rates.
Downloaded from
jn.nutrition.org
by guest on March 23, 2013

BASAL HEAT OF THE EHESUS MONKEY 359
Animal no. 37 which gave the highest value of the group was
extremely excitable and it is conceivable that this high heat
production may be accounted for by the emotional dis
turbances pointed out by Benedict ('35) and by the cardiac
and respiratory factors which have recently been demon
strated by Carpenter et al. ( '34) to produce a considerable
augmentation in the 02 consumption of normal individuals
in the basal state. It is interesting to note that Bruhn ( '34)
obtained a value of 701 Cal. on one of the animals in his series.
TABLE 1
Results of metabolic rate determinations on eleven rhesus monkeys
ANIMAL
LITERS/
O»HOURS

360 NATHAN EAKIETEN
animals nos. 30 and 4, both of which gave values of 543 Cal.,
must be attributed to their individual differences. It was sur
prising to find two animals of different weight and sex that
had the same low basal metabolic rate. It is perhaps unwise
to use the average metabolism of the group.
The trend of similar metabolic determination for the two
sexes was noted throughout the investigation. The average
heat production of the female group was 3.2 per cent higher
than the male, 618 Cal. as compared with 598 Cal., a difference,
however, which is well within the experimental error. More
over, if the values obtained on animal no. 37, a female, are
excluded the average results for the female group becomes
600 Cal., a value closely approximating the heat production of
the males. It is possible that when more data on the heat
TABLE 2
B. M. S. of monkey no. 37 which received SS mg. amytal/Teïlo
HOURSPOST
AB8.24
IN KILOS3.5
LITERS/III!.1.680
S

BASAL HEAT OP THE RHESUS MONKEY 361
were slightly lower than those reported by Bruhn ( '34), a dif
ference that probably resulted from our use of a longer postabsorptive
period.
SUMMARY
1. The average basal heat production of eleven adolescent
rhesus monkeys was found to be 608 Cal./square meter/24
hours.
2. A similar heat production was observed for the males
and females.
2. Two experiments on one animal which received 35 mg. of
sodium amytal/kilo gave results almost identical with those
obtained on it under normal basal conditions.
ACKNOWLEDGMENT
It is a pleasure to acknowledge the interest and cooperation
shown by Dr. J. F. Fulton all during this investigation. The
author also wishes to express his gratitude to Dr. F. G. Bene
dict for his advice and aid during the study.
LITERATURE CITED
ANDERSON,H. H., M. Y. CHEN ANDC. D. LEAKK 1930 Effects of barbituric acid
hypnotics on basal metabolism in humans. J. Pharm. and Exp. Ther.,
vol. 40, p. 215.
BENEDICT,F. G., 1927 A 'field respiration apparatus' for a medical and
physiological survey of racial metabolism. Bost. Med. Surg. .T., vol.
197, 1935 p. 1161. Degree of constancy in human basal metabolism. Am. J.
Physiol., vol. 110, p. 521.
BENEDICT,F. G., AND J. ROMANS 1912 The metabolism of the hypophysectomized
dog. J. Med. Res., vol. 25, p. 409.
BENEDICT,F. G., AND F. G. TALBOT 1921 Metabolism and growth from birth
to puberty. Carnegie Inst. Wash. Pub. no. 302.
BOTSCHKABEFF,P. W. 1933 Arch. d. Sci. Biol., vol. 32, No. 1-2, p. 245. (Cited
by Bruhn, '34).
linens', J. M. 1934 The respiratory metabolism of infrahuman primates. Am.
J. Physiol., vol. 110, p. 477.
CARPENTER,T. M. 1933 Ein Apparat zur Analyse von Gasen aus Respiration
kammern fürMenschen und Tiere. Abderhalden's Handbuch d. Biol.
Arbeitsmethoden, Abt. IV, S. 593.
Downloaded from
jn.nutrition.org
by guest on March 23, 2013

362 NATHAN BAKIETEN
CARPENTER,T. M., AND E. L. Fox 1931 An apparatus for continuous short
period measurements of human respiratory exchange during rest and
muscular work. Arbeitsphysiol., vol. 4, p. 527.
CARPENTER,T. M., B. G. HOSKINS AND F. A. HITHCOCK 1934 Voluntarily in
duced increases in the rates of certain 'involuntary' physiological
processes of a human subject. Am. J. Physiol., vol. 110, p. 320.
DEÃœEL,H. J., JR., W. H. CHAMBERSAND A. T. MILHORAT 1926 The influence
of amytal upon the metabolism of the dog. J. Biol. Chem., vol. 69,
p. 249.
LEE, M. O., ANDE. L. Fox 1933 Surface area in a monkey, Macacus rhesus.
Am. J. Physiol., vol. 106, p. 91.
SIEBEBT, W. J., AND E. W. THURSTON 1932 Effect of amytal upon basal
metabolism in guinea pigs. Proc. Soc. Exp. Biol. and Med., vol. 29,
p. 650.
p;
i 3
?.'•-
Downloaded from
jn.nutrition.org
by guest on March 23, 2013