Purdue University Veterinary Medical
VOLUME 10, NUMBER 2
SUMMER- FALL 1984
Neuropharmacology at Purdue
Significance of Dopamine Sulfate in Mammals Investigated
of dopamine sulfate in the blood is complicated by the finding of graduate student, Grace Kao, D.V.M., that the drug
(probenecid) commonly used to block
transport for studies of this type also in-
Dopamine is an endogenous catecholamine which functions as a neurotransmitter and neurohormone. Dopamine sulfate
is the predominant form of dopamine
which occurs in the blood of most higher
mammals. Our laboratory is currently investigating the sources, functions, and
metabolic activity of dopamine sulfate in
mammals.
We have recently developed several novel
methods for measurement of dopamine
sulfate isomers in biological samples. The
most sensitive technique uses high performance liquid chromatography (HPLC)
coupled with dual electrode electrochemical detection and can detect as little as
10"10 grams of either dopamine sulfate
isomer (see figure). Patrick Swann, a
graduate student, has developed a sample
clean-up procedure which allows us to
measure trace amounts of dopamine sulfate in a variety of "dirty" biological samples, such as blood and urine, and now,
along with fellow student, Mary Scott, is
investigating the pharmacokinetic properties and metabolic conversions of dopamine sulfate in dogs.
The sources of the substantial amounts of
dopamine sulfate in the blood are also being studied. Linda Toth, Ph.D., a veterinary medical student and part-time postdoctoral fellow, has demonstrated, in
vitro, that platelets from human blood accumulate free dopamine and convert up
CH2-CHj-
Dr. Mary Ann Elchisak (left) and graduate students, Mary Scott and Patrick Swann,
conduct experiments to measure dopamine sulfate.
HO'
DA - 3 - O- sulfate
*T?r
CH2-CH2-NH2
CH2-CH2-NH2
/
w,?+t.oov a^^/C^ w2saoov
-►      I
,CH2_CH2-NH2
nnPAMINF
OA - 4 - O - sulfate
Proposed mechanism for dual-electrode detection of dopamine (DA) sulfate. As each
isomer elutes from the HPLC system (not shown), it is oxided to a quinone at the upstream (Wl) electrode. The quinone is reduced to free DA at the downstream (W2)
electrode by "recapture " of electrons. The electrical response at W2 is measured and
used to quantitate the amount of DA sulfate in a sample. The distinction between the
two DA sulfate isomers is maintained as a temporal separation in the HPLC procedure.
to 60 percent of it to dopamine sulfate.
Experiments conducted in the isolated
^effused rat kidncv/ bv< resenrch associate
Moafak Jasim, D.V.M., in collaboration
with Philip Mayer, Ph.D., in the School of
Pharmacy, indicate that the rat kidney also converts free dopamine to dopamine
sulfate. These studies suggest that both
platelets and kidney are likely sources for
much of the dopamine sulfate found in
the blood.   Study of the brain as a source
hibits the enzyme which converts dopamine to dopamine sulfate.
Results of these studies are increasing our
understanding of catecholamine synthesis
and metabolic mechanisms. Ultimately,
they might aid in the treatment of diseases, such as essential hypertension and
various neurological disorders, in which
catecholamines are thought to be contributing factors.
Mary Ann Elchisak, Ph.D.
Silver Anniversary
Development Campaign
Yeager & Sullivan Contribute 1st Check
Charles Yeager and his daughter, Dr. Marianne Ash of Yeager & Sullivan, Flora, Indiana, presented a check for $10,000 to Dean Jack J. Stockton in June 1984. It was
the first contribution received for the SVM Silver Anniversary Development Campaign.
The V'eager[Sullivan pledge of $50,000 over the five years of the campaign also makes
them the first member of our School of Veterinary Medicine Leadership Club. The interest and generosity of the Yeager family is greatly appreciated by the School of Veterinary Medicine. Yeager & Sullivan is a poultry, swine and feed business. Marianne
Yeager Ash is a DVM '77 graduate. Her husband, Stephen P. Ash, M.D., is an adjunct
associate professor in the Department of Small Animal Clinics.
^r1 Wayne Woodrow Kirkham
1918-1984
Retiring from Purdue University on 30
June 1984, as Professor Emeritus and
moving to Panama City, Florida, in mid-
July, Wayne celebrated his 66th birthday
there on 20 July in the midst of the family which he loved so deeply. On 24 July,
without signals of serious problems, death
came while he slept.
Prior to earning degrees from Texas A&M
University (DVM'41 and MS'55) and
from Iowa State University (Ph.D.
Microbiology'62), he practiced and served
with the USDA in his native Hoosier
state. He spent a year in 1955-56 on the
staff at Kansas State University. Following graduate work, he spent six years in
Florida with the Florida Department of Agriculture at Kissimmee and with the
University of Florida at Gainesville, coming to Purdue in July 1968, to head the
Animal Disease Diagnostic Laboratory. Many improvements were effected in
this unit, which he headed until July 1978, when he assumed the title of veterinary diagnostician.
People and horses were his great loves. Upon learning of his death, two former
students wrote: "... It was a shock to learn of the sudden death of Dr. Kirkham, our good friend and mentor. The friendship and help he gave us both during veterinary school and afterwards as we initiated our careers has been deeply
appreciated and is an example to us. His generosity cannot be repaid except as
we try to live up to his example." An eloquent testimony to a warm, interested,
concerned, and contributing colleague.
The family asked that those wishing to remember Wayne may contribute
to the IVMA Scholarship Fund in his memory.
^i^il