Katy McHenry
&
Dr. Fredrick Stormshak
Department of Animal Sciences
Oregon State University
• Bovine Estrous Cycle = 21
days
• One egg matures
• Released as an oocyte
• Granulosa cells of the empty
follicle turn into the corpus
luteum
• Angiogenesis
• Endocrine Gland
 Stimulation of milk letdown
 Smooth muscle contraction in
uterus during childbirth
 Roll in maternal instinct
and building relationships?
Bovine luteal oxytocin acts locally to
stimulate the proliferation and migration
of endothelial cells to form the vascular
system of the developing corpus luteum.
Corpus
Luteum can
not form
1. Block oxytocin
receptors
Progesterone
2. Tumor
angiogenesis and
growth
1. Isolate the endothelial
cells
2. Measure the binding of
oxytocin to endothelial cell
oxytocin receptors
• Check cows for estrus using
vasectomized bull
• Remove corpus luteum eight days
post-estrus
 Dissociate corpus luteum using
collagenase and DNAse
 Tosyl-activated magnetic
beads
 Couple with lectin BS-1
 Add dissociated tissue and
separate endothelial cells

[ H]-Oxytocin
3
[
3
H]-Oxytocin & 200 fold
excess unlabeled Oxytocin
Results
Results
New Theory
 Pericyte Cells
 Stem Cells
Smooth Muscle
Results
Summary
 Oxytocin showed slight binding to
receptors on endothelial cells in the
corpus luteum.
 Hypothesis was not strongly supported
 Large amount of oxytocin binding to
receptors on non-endothelial luteal cells
 Possibly pericyte cells?
 Dr. Fred Stormshak
 Oregon State University, Department of Animal
Sciences
 Oregon State University, Honors College
 Dr. Kevin Ahern
 The Howard Hughes Medical Institute