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VOLUME 5, NUMBER 2
SUMMER     FALL 19 79
EXPERIMENTAL STUDIES ON ENDOTOXIC SHOCK IN HORSES
Endotoxic shock in the horse is a primary problem
associated with gastrointestinal diseases and acute
abdominal crisis. Tremendous numbers of gram-negative
organisms in the large intestine make available a large
pool of endotoxin which can be absorbed and lead to
endotoxic shock when the gut is obstructed. Endotoxin-
induced changes have been reported in many animals
and widespread derangements of the cardiovascular
system occur. A characteristic triphasic response which
includes an initial fall, a partial recovery, and a precipitous terminal fall in blood pressure is usually observed.
The exact nature and cause of the cardiovascular derangements are unknown, but the microcirculation has
been repeatedly implicated in the pathophysiology of
shock. Knowledge about the tissue perfusion of all
organs is of great interest due to the marked fall in blood
pressure, decreased cardiac output, and generalized vasodilation that accompanies endotoxic shock.
Research activities at Purdue have included experiments
designed to characterize regional blood flow changes,
cellular damage and energy deficits in horses during
endotoxic shock and to determine the benefits accruing
from the use of massive steroid therapy.
A technique using microspheres labeled with radionuclides to determine blood flow to all major organs at
different times during endotoxic shock has been developed. Ponies are being used in the current experimental
work. Shock is induced by the intravenous injection of
Escherichia co//-derived endotoxin. Blood flow (ml/
min/g) to major organs is measured using radionuclide
labeled 15u microspheres and cardiorespiratory actions
are constantly monitored. Blood samples taken at
regular time intervals are analyzed for glucose, insulin,
plasma enzymes, isoenzymes, and clotting factors to
determine energy deficits and specific tissue changes.
The schematic diagram illustrates the experimental
model.
The use of microspheres labeled with different radionuclides is the only technique by which multiple measurements of simultaneous flow to all organs and tissues
can be obtained. When injected into the left ventricle,
the microspheres are distributed to all tissues in the same
manner as arterial blood. They are trapped in the capillary beds (see illustration) and yield information which
can be used to calculate the relative blood flow to each
organ at the time of injection. The percentage of total
capillaries in the microvasculature blocked by microspheres is small and the reduction of blood flow to the
capillary bed by such blockage is minimal.
Microspheres (15u) labeled with different radionuclides are
trapped during their first pass through the capillaries. The
percentage of capillaries in the microvasculature blocked by the
microspheres is small and causes no significant reduction in
blood flow. The amount of radiation coming from the trapped
microspheres can be used to calculate the relative blood flow to
each organ.
Schematic diagram of the experimental model showing cannulae used for injecting labeled  microspheres, collecting samples and
monitoring cardiorespiratory changes.
Data on organ perfusion during times of specific tissue
damage and irreversible shock are required to determine
the ability of various therapeutic agents to maintain
normal organ perfusion, thus providing a more rational
approach to shock therapy. Additionally, knowledge
about regional and organ blood flow should contribute
to the understanding of any clinical disease thought to
be related to poor tissue perfusion, e.g., adynamic ileus
and rhabdomyolysis.
These studies are continuing with the ultimate goal of
determining the effect of steroid therapy first on experimentally-induced endotoxic shock, and if promising
in the experimental model, then on selected cases of
naturally occurring gut blockage with developing endotoxic shock manifestations.
Drs. Bottoms, Fessler and Frauenfelder and Mr. Moore
Investigators involved in the endotoxic shock research are
(I to r): Dr. H. C. Frauenfelder, Dr. G. D. Bottoms, Mr. A.
Moore, Mrs. Martha Johnson, Mr. H. Latshaw, and Dr. J. F.
Fessler.
TWO DISTINGUISHED ALUMNUS AWARDS
ness to trans/ate his convictions into productive action
which is clearly evident and appreciated by those whose
lives he touches. By reason of such high devotion, he
brings recognition and acclaim, not only to himself, but
also to his profession and to the University which helped
to give him direction.
Dr. Carl A. Osborne, Class of 1964, of Saint Paul,
Minnesota, was recognized for excellence in teaching,
excellence in research, and excellence in clinical practice.
The inscription on the plaque, symbolic of the recognition, presented to Dr. Osborne reads:
In recognition of outstanding accomplishments and
contributions in the areas of veterinary medical education, research, and clinical services, with particular acclaim for leadership and authorship in renal physiology
and kidney diseases in companion animals; for the genuine and deep concern for the attitude of colleagues and
for the profession which he proudly represents; and, for
the standard of excellence which he demands of himself
and which serves as a shining example for others.
The Distinguished Alumnus Award Program was begun
in 1978, and is supported by contributions from members of the Class of 1967 and others, in recognition and
memory of Dr. David R. Mullis, a member of the Class
of 1967 and a veterinary medical practitioner in Lyons,
Indiana, who was awarded, posthumously, the first
Distinguished Alumnus Award in 1978.
J. J. Stockton
Haines
Osborne
Banquet time during the Fall Conference and Alumni
Reunion was the occasion for the presentation of the
second and third Distinguished Alumnus Awards granted
by the School.
Dr. William A. Haines, Class of 1965, of Newington,
Connecticut, was recognized for excellence in community service, excellence in organized veterinary medicine,
and excellence in the practice of his profession. The
inscription on the plaque, symbolic of the recognition,
presented to Dr. Haines reads:
In recognition of a deep sense of total community, both
personal and professional, and for the ability and willing-