Dr. Wilkes Gets Research Grant

              Heart Study Outlined—
Dr. Wilkes Gets
Research Grant
By MERRILEE LEATHERMAN
Journal Staff Writer
The Louisiana Heart Assn.
has awarded $3,870 to Ann B.
Wilkes, Ph. D., for research in
cardiovascular diseases and
function.
Dr. Wilkes, assistant profes-sor
in the department of
Pharmacology and Therapeu-tics,
LSU School of Medicine
in Shreveport, will use the
grant for a period of one year
in her research project, "Role
of Calcium in Excitation-con-traction
of Atria."
THIS PROJECT proposes to
study specifically the role of
calcium and the mechanism
of excitation-contraction in the
normal and failing atrium of
the rabbit heart.
The results of the project,
according to the r e s e a r c h
outline, should be a determi-nation
of the normal ultras-tructure
of the atria and is
relation to normal contraction
and ultrastructure changes in
the contracile failure.
The invesigator says some
drugs such as digitalis and
caffeine appear to produce or
modify the mechanism of
contraction in muscle by in-creasing
calcium from intra-cellular
exchange across the
membrane by causing the
release of calcium from in-tracellular
storage sites or
inhibiting the ability of the
muscle cell to adjust its
calcium levels.
SEVERAL GROUPS of in-vesigators
already have
shown there is a defect in
calcium transport in various
components of the muscle cell
and a functional abnormality
of the calcium regulating
system in the intact myocar-dial
cell in heart failure. This
could lead to changes in the
excitability and contractility
of clinioal importance.
Therefore, nominal function
of heart muscle appears to
depend on the regulation of
calcium within the cardiac
cell, but the precise mecha-n
i s m s responsible for the
changes in intracellular con-centration
of free calcium
necessary to effect the
contraction relaxation cycle
remain to be determined.
This reportedly is particu-larly
true in cardiac muscle
where the concepts of excita-tion
and contraction that have
been determined for skeletal
muscle will no apply due to
the difference in ultrastruc-ture.
DR. WILKE'S study will
involve a detailed study of the
ultrastructure of the normal
rabbit atria to use for com-parison
purposes. She will
treat the tissue with special
stains to elucidate the area
occupied by the extracellular
space.
Another stain will permit
semi quaniatie estimation
of the location of sodium,
magnesium and calcium by
precipitation of these cations
within the cell-
The atria will be treated
with solutions known to pro-duce
a failure of the coupling
of excitation to contracton.
The changes in the tension
produced by the muscle will
be correlated with the ultra-s
t r u c t u r a l changes and
changes in cation content —
especially calcium.
VARIOUS DRUGS will be
used to change the contractili-ty
of the muscle and again,
the ultrastructure and cation
content will be observed.
Dr. Wilkes, who was with
the Department of Pharma-cology
at the University of
Mississippi M e d i c a l School
before coming to Shreveport,
is the co-author of numerous
scientific articles and pre-viously
has received a grant-in-
aid from the Mississippi
Heart Assn.
Fellowships she has re-ceived
include a predoctoral-
NIH General Medical 'Sciences
from 1965-69, and two re-search
fellowships from the
Mississippi Heart Assn.
She is the wife of Thurston
E. Wilkes II, M.D. They are
the parents of one son, Thurs-ton
E. Wilkes, III.