Gonadotropin stimulation may not affect the expression of heparin-binding epidermal growth factor-like growth factor in the murine endometrium.
BACKGROUND
Present human data reveal that gonadotropin stimulation for in vitro fertilization and embryo transfer (IVF-ET) is detrimental to uterine receptivity. Heparin-binding epidermal growth factor-like growth factor (HB-EGF) is important in the early stage of mouse embryonic implantation since it is expressed in the murine endometrium before the attachment reaction. Gonadotropin receptors have been found on the murine endometrium. In this study, we assessed the expression of HB-EGF mRNA on the gonadotropin-stimulated murine endometrium and sought evidence of whether the gonadotropin-induced, altered uterine receptivity is associated with a change in the HB-EGF expression.


METHODS
Quantitative, competitive reverse-transcription polymerase chain reaction (PCR) and immunohistochemistry were performed to evaluate the expression of HB-EGF mRNA on the stimulated murine endometrium from pregnant uteri of gestation day (g.d.) 5.0 after injection of saline, or pregnant mare serum gonadotropin (PMSG) 5 or 10 IU.


RESULTS
The expression of HB-EGF mRNA showed no significant increase or decrease in the endometrial expression in PMSG groups, compared to the control group (natural coitus with saline injection), on g.d. 5.0. This finding was consistent with the immunostaining of HB-EGF protein, and there was no significant difference in the staining intensity among the 3 groups.


CONCLUSIONS
This study reveals that ovarian stimulation by gonadotropin may not influence the expression of HB-EGF in the murine endometrium. Further investigations are necessary to elucidate whether embryonic HB-EGF receptor status relative to endometrial HB-EGF expression is affected by ovarian stimulation.
Ku
Seung-Yup
SY
Department of Obstetrics and Gynecology, Division of Reproductive Endocrinology and Infertility, College of Medicine, Seoul National University, Seoul, Korea.
Jee
Byung Chul
BC
Suh
Chang Suk
CS
Kim
Seok Hyun
SH
Choi
Young Min
YM
Kim
Jung Gu
JG
Moon
Shin Yong
SY
D000818:Animals; D004717:Endometrium / Q000187:drug effects* / Q000378:metabolism; D004815:Epidermal Growth Factor / Q000096:biosynthesis* / Q000187:drug effects; D005260:Female; D005300:Fertility Agents, Female / Q000494:pharmacology*; D006062:Gonadotropins / Q000494:pharmacology*; D066257:Heparin-binding EGF-like Growth Factor; D036341:Intercellular Signaling Peptides and Proteins; D051379:Mice; D010062:Ovulation Induction / Q000379:methods; D011247:Pregnancy; D012333:RNA, Messenger; D020133:Reverse Transcriptase Polymerase Chain Reaction
D005300:Fertility Agents, Female; D006062:Gonadotropins; C587883:HBEGF protein, human; C587884:Hbegf protein, mouse; D066257:Heparin-binding EGF-like Growth Factor; D036341:Intercellular Signaling Peptides and Proteins; D012333:RNA, Messenger; D004815:Epidermal Growth Factor