Angiogenesis in the human corpus luteum: simulated early pregnancy by HCG treatment is associated with both angiogenesis and vessel stabilization.
BACKGROUND
This study examined changes in the luteal vasculature throughout the menstrual cycle and during simulated pregnancy with human chorionic gonadotrophin (HCG) in the human.


METHODS
Endothelial cell and pericyte area were assessed by quantitative immunocytochemistry for CD34 and alpha-smooth muscle actin respectively, taking into consideration the dynamics of lutein cell hypertrophy and atrophy throughout the cycle and after HCG treatment. Endothelial cell proliferation was detected by Ki-67/CD34 dual staining and a proliferation index was obtained. The molecular regulation of angiogenesis was studied by examining changes in vascular endothelial growth factor (VEGF) immunostaining.


RESULTS
The early luteal phase is associated with intense angiogenesis, as indicated by high endothelial cell proliferation, and by the mid-luteal phase a mature vasculature was apparent, as shown by maximal endothelial cell and pericyte areas. During the late luteal phase, decreased endothelial proliferation, endothelial cell and pericyte area indicated vascular regression. HCG treatment induced a second burst of total and endothelial cell proliferation and a concomitant increase in endothelial cell and pericyte areas. VEGF protein was expressed throughout the luteal phase and a significant increase was found after HCG treatment.


CONCLUSIONS
Luteal rescue with HCG is associated with a second wave of angiogenesis and vascular stabilization.
Wulff
C
C
Medical Research Council, Human Reproductive Sciences Unit of the University of Edinburgh, Centre for Reproductive Biology, 37 Chalmers Street, Edinburgh EH3 9ET, UK. Christine-wulff@onlinehome.de
Dickson
S E
SE
Duncan
W C
WC
Fraser
H M
HM
D000199:Actins / Q000032:analysis; D000328:Adult; D018952:Antigens, CD34 / Q000032:analysis; D002455:Cell Division; D048429:Cell Size; D006063:Chorionic Gonadotropin / Q000494:pharmacology*; D003338:Corpus Luteum / Q000098:blood supply*; D016228:Endothelial Growth Factors / Q000032:analysis; D004730:Endothelium, Vascular / Q000737:chemistry / Q000166:cytology; D005260:Female; D006107:Granulosa Cells / Q000166:cytology; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000032:analysis; D008184:Luteal Cells / Q000166:cytology; D008183:Luteal Phase; D008222:Lymphokines / Q000032:analysis; D008597:Menstrual Cycle; D008875:Middle Aged; D018919:Neovascularization, Physiologic; D011247:Pregnancy; D013799:Theca Cells / Q000166:cytology; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
D000199:Actins; D018952:Antigens, CD34; D006063:Chorionic Gonadotropin; D016228:Endothelial Growth Factors; D019394:Ki-67 Antigen; D008222:Lymphokines; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors