Morphological analyses of interleukin-8 effects on rat ovarian follicles at ovulation and luteinization in vivo.
The aim of the present study was to elucidate functions of the interleukin (IL)-8 at ovulation and luteinization in vivo. To compare the morphological differences between human chorionic gonadotropin (hCG) and IL-8 stimulation, scanning electron microscopy was employed to study rat ovarian vascular corrosion casts. Follicular growth and increased capillary vessel densities around the follicles were seen in vascular corrosion casts after IL-8 injection, similar to the result of hCG administration. This result indicated that exogenous IL-8 could play a role in the neovascularization during follicular development as an angiogenetic factor. Many fenestrations were observed in the vascular endothelium by hCG administration. In contrast, no fenestrations were observed with IL-8 injection, indicating that IL-8 may not be sufficient to increase the vascular permeability directly. Although germinal vesicle breakdown (GVBD) occurred at rates of 82% after the hCG injection, only 20% GVBD was observed after the IL-8 injection. The present study indicated that IL-8 might have important effects on rat follicles at ovulation and luteinization via vascularization in a similar manner to hCG. However, IL-8 was not effective on vascular permeability and oocyte maturation, which were different from hCG. Thus, we can conclude that IL-8 can participate in follicular development in part and may play important roles in ovulation and luteinization as one of some mediators induced by endogenous luteinizing hormone.
Goto
Junko
J
Department of Obstetrics and Gynecology, Hamamatsu University School of Medicine, Hamamatsu 431-3192, Japan.
Suganuma
Nobuhiko
N
Takata
Kayoko
K
Kitamura
Kimiya
K
Asahina
Toshihiko
T
Kobayashi
Hiroshi
H
Muranaka
Yoshinori
Y
Furuhashi
Madoka
M
Kanayama
Naohiro
N
D000818:Animals; D006063:Chorionic Gonadotropin / Q000494:pharmacology; D016319:Corrosion Casting; D004730:Endothelium, Vascular / Q000187:drug effects / Q000648:ultrastructure; D005260:Female; D006064:Gonadotropins, Equine / Q000494:pharmacology; D006801:Humans; D016209:Interleukin-8 / Q000494:pharmacology*; D034461:Luteinization / Q000187:drug effects*; D007986:Luteinizing Hormone / Q000502:physiology; D008855:Microscopy, Electron, Scanning; D009865:Oocytes / Q000187:drug effects; D009866:Oogenesis / Q000187:drug effects; D006080:Ovarian Follicle / Q000098:blood supply / Q000187:drug effects* / Q000648:ultrastructure; D010060:Ovulation / Q000187:drug effects*; D010062:Ovulation Induction; D051381:Rats; D017208:Rats, Wistar
D006063:Chorionic Gonadotropin; D006064:Gonadotropins, Equine; D016209:Interleukin-8; D007986:Luteinizing Hormone