Objective: To study angiogenesis and microcirculation in experimental pancr
Designs: Open experimental study.
Setting: 2 University hospitals, Germany and USA.
Animals: 16 male Lewis rats.
Interventions: Induction of a duct-like pancreatic cancer in the pancreas a
nd peritoneum by interposition of fragments of tumour between 2 inert trans
parent polymethylmethacrylate plates.
Main outcome measures: Microcirculation in the tumour and interaction betwe
en leucocytes, tumour, and endothelium investigated by intravital microscop
Results: The density of vessels in the carcinoma was significantly less tha
n in normal pancreatic tissue (p = 0.0004). The vasculature of the tumour w
as characterised by a lack of differentiation in architecture of vessels, f
ormation of sinusoidal and lacunar vessels and sudden changes in diameter o
f vessels. Red blood cell velocity differed among tumour vessels, but. mean
values were similar to those of normal exocrine pancreas. The mixed lympho
cyte culture test indicated that the cell line DSL6A was immunogenic. Howev
er, high-affinity leucocyte-endothelium-interaction was significantly reduc
ed in the tumour's microcirculation after both orthotopic and heterotopic i
mplantation (p = 0.002). Rates of apoptosis were suppressed in heterotopic
tumours compared with orthotopic ones. Tumour growth was faster in heteroto
Conclusions: Experimental duct-like pancreatic carcinoma can be differentia
ted from normal pancreas by: chaotic arrangement of vessels with loss of di
fferentiation of architecture and heterogeneous distribution; the formation
ai: sinusoidal or lacunar vessels; lower vascular density with similar ery
throcyte velocity; increase in mean diameter of vessels; reduced leucocyte-
endothelium interaction despite confirmed immunogeneity independent of wall
shear rates. The site of implantation influences apoptosis and growth rate