Wednesday,- November 23, 1S34
Dally Ncbrcskan
Man-like pony hearts
used for UNL study
In the surgery room of UNL's
Basic Veterinary Science complex,
veterinary physiologist James
Amend performs open-heart
surgery on his patient who lies
on a hydraulic lift. A no-pest strip
hangs overhead. His patient is a
pony.
The operation is a "sham experi
ment" part of the pony Jheart
research Amend has been con
ducting since his graduate stu
dies 15 years ago at the Baylor
Medical Center. Amend said re
search shows that the micro
vessels of the pony heart resem
ble human hearts closely.
Amend said researchers prefer
dog and pig hearts for studies,
claiming they more closely re
semble the human heart.
There has been a great deal of
argument about the usefuilness
of the dog and also the pig as
experimental models for coronary
heart research in man," Amend
said.
Amend said a dog's heart is the
poorest example of the three be
cause it doesn't have the micro
vessel distribution the other two
have. The anatomical supply of
the main arteries is the same in
both the pig and pony, he said.
Pony and human hearts have
two similarities that dog and pig
hearts dont, Amend said.
The dog and the pig tend to
have more of their small coro
nary vessels in the outer layers
lurthest from the heart muscle
and the heart chambers, whereas
the pony has more of its small
vessels concentrated in the inner
layers, closer to the ventricular
chamber of the heart " Ameijd
said.
Amend's study includes map
ping the patterns of the heart's
vessels, taking photographs of
them, and studying the vessel
patterns under the microscope.
Researchers also are looking at
the major vessel along the front
of the heart, Amend said. This
vessel supplies most of the left
side of the heart muscle and
often is involved in the most dan
gerous form of human heart
attacks, he said.
Amend discovered the similar
ities between pony and human
hearts while he was researching
at the University of Missouri He
continued that work at UNL.
What we want to do first is to
characterize the basic anatomy
of the large, small and even micro
scopic vessels of the pony cor
n ary arteries, comparing those to
dog and pig arteries and then to
the literature concerning the
anatomy in man," he said.
. "We hope that we can develop
this model to the point where it's
a convincing model, where its
benefits over and above the other
species are clear " Amend said.
Amend said he also hopes to go
federal agencies such as the
National Institute of Health and
tell them of the "better mouse
trap; the better model to study
heart disease and do heart
research."
Amend - said he has received
money from the NU Research
Council for biomedical research
and from the Natonal Institute of
Health.
Although the research usually
ends in the death of the pony,
Amend said, an "astute livestock
person" has been hired to buy
ponies that are cleary undesira
ble for other purposes ponies
that are lame or have temper
problems: The entire surgical
process is not painful, he said.
About 45 minutes after the
operation, the pony is usually on
his feet, he said. In another 45
minutes, the animal is back in its
stall. About two hours after the
operation the animal is eating.
Amend said he hopes to per
form chest surgery successfully
by the end of next year.
"We want to implant devices
that will stimulate heart attacks
for study, and we hope our map
ping process will confirm that we
have a heart with a set of coro
nary arteries that are more sim
ilar to man's than the pig and
dog."
i I
.J
Upper right: James Amend sutures the incision v1th kelp
from Amy Valentine. Eight: Mike Traxmer checks the pony's
eye reflexes to determine hew anesthetized the animal is.
Above: Open heart surgery is performed. Lower rights Valen
tine and Chris Oitsnmn walk the psay back to its etsll less
than two hours after Vas operation.
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