THE BABOON IN MEDICAL RESEARCH WITH PARTICULAR 
REFERENCE TO KIDNEY TRANSPLANTATION 
G. P. Murphy* 
Subhuman primates have specific applicability in 
current areas of research. The baboon has been found 
to have merit in the field of organ transplantation. 
Pertinent technical and related information concerning 
the use of this species in organ allotransplantation 
research is presented. 
INTRODUCTION** 
Research models in many fields have not nec- 
essarily reflected the degree of knowledge avail- 
able or the rate of clinical activity. The develop- 
ment of the baboon as a suitable subhuman 
transplant model followed rather than preceded 
many human organ allotransplantation ef- 
forts.i-'' In the case of human cardiac trans- 
plantation it played, in my opinion, a significant 
role.^ Many questions in clinical transplanta- 
tion remain to be answered. Some are never 
likely to be answered in the present patient 
settings because of the hazard to the patient. 
On the other hand, there remains much to com- 
mend the use, in selected circumstances, of 
subhuman primates such as baboons to deal with 
problems such as evaluation of antilymphocyte 
globulin effectiveness.^ Obviously, there are 
other subhuman primates, such as the rhesus 
monkey, which have been most successfully em- 
ployed in various ways by others.^'' However, 
there can be considerable technical problems 
with organ allografts using monkeys.^^-i^ The 
♦ Roswell Park Memorial Institute, New York State Department 
of Health, Buffalo, New York 14203. 
These studies were supported in part by U.S.P.H.S. NIH Grant 
#FR 05648-05. 
present report will discuss pertinent aspects of 
the use of the baboon as an organ transplant 
model with particular reference to kidney 
transplantation. 
Vascular Aspects 
One hundred and forty kidney transplants 
were done with the en bloc (aorta and inferior 
vena cava) and single artery method and were 
compared in relationship to immediate kidney 
function and the observed incidence of graft 
thrombosis occurring within the first 7 days 
after transplantation. Table I summarizes the 
apparent causes of death in these two series. 
The incidence of thrombosis was only slightly 
higher (34.1%) in the single kidney transplants 
as compared to the en bloc transplantations 
(28%) (Table I) . This difference of only 6% is 
less than would be expected, considering the 
relative size of the vessels used for anastomoses 
in the two series. The en bloc grafts usually had 
an average vascular diameter of 3-4 times that 
of the single kidney transplants. In terms of the 
cross-sectional area at the anastomotic site, the 
difference between the two groups is even 
greater. 
The clinical rejection rate of the two groups 
(50% for the single kidney transplants and 
47.1% for the en bloc transplants) is virtually 
the same in the two series (Table I). In other 
animals, death resulted from the toxicity of 
some of the immunosuppressive agents used or 
from other systemic causes (Table I) . 
Table I. — Causes of Death of 280 Baboon Kidney Transplants 
Type of Total Thromboses Rejection Other Causes 
Transplant Done No. Percent No. Percent No. Percent 
En bloc 
2 kidneys _ 140 40 28.0 66 47.1 34 24.9 
Single kidney 140 48 34.1 70 50.0 22 15.9 
Total _ 280 88 136 56 
398 
