F. K. MERKEL 
377 
Figure 3. — The canine segmental pancreatic allograft 
following completion of the anastomoses. The celiac 
axis (CA) is anastomosed to the proximal iliac ar- 
tery (PI A) and the splenic artery (SA) to the distal 
iliac artery (DIA). The portal vein (PV) is sutured 
to the inferior vena cava (IVC) at the take off of the 
iliac vein and the superior mesenteric vein is sutured 
to the distal iliac vein (IV) proximal to the junction 
of the external iliac vein (EIV) and the hypogastric 
vein (HV). Note the delicate appearance of the 
transplanted gland and the freedom from hemor- 
rhage. 
hemorrhagic with a markedly thickened cap- 
sule. A marked round cell infiltrate is seen on 
histologic section (Figure 7) . The non-rejecting 
canine transplant invariably exhibits prominent 
beta cell granulation to the aldehydefuchsin re- 
action. The transplanted gland responds to the 
prednisone used for immunosuppression by 
sprouting off new beta cells from the ductile 
system of the gland in just the same way as a 
normal, non-transplanted pancreas responds to 
steroids (Figure 8). Some of the duck ligated 
glands which served more than six weeks exhib- 
ited marked fibrosis (Figure 9) . 
Studies were carried out to determine the ef- 
fect of ischemia on the pancreas transplant in 
the laboratories of Largiader, Bergan and Mer- 
kel (14-17). A significant finding was that the 
fasting blood sugar was not the best indicator 
of the presence or absence of ischemic injury 
(Figure 10). For, although normal fasting 
blood sugar was recorded after 90 minutes of 
normothermic ischemia, glucose tolerance 
curves clearly demonstrated the damage in- 
curred by the transplant. At 90 minutes, the 
damage appeared reversible; however, at 190 
minutes, the glucose tolerance and insulin 
curves were permanently altered (Figure 11). 
Ischemia also resulted in early hyperinsuli- 
nemia, presumably a result of injury to the beta 
cell membrane causing increased permeability. 
Thus, one hour was predicted as the maximum 
period of normothermic ischemia allowable in a 
human pancreatic transplant. 
The canine experiments thus demonstrated 
the technical feasibility of pancreatic trans- 
PiGURE 4. — Alloxinated dog following pancreatic allo- 
grafting several weeks prior to sacrifice at 98 days. 
Note his healthy appearance. He exhibited normal 
blood glucose and insulin levels in the absence of gly- 
cosuria. Glucose tolerance curves were within normal 
limits. 
