Interleukin-6 stimulates gonadotropin-releasing hormone secretion from rat hypothalamic cells.
There are reports that both interleukin-1 beta and interleukin-6 (IL-6) stimulate the release of adrenocorticotropin through stimulation of hypothalamic corticotropin-releasing factor. We established a primary culture system for hypothalamic neurons producing gonadotropin-releasing hormone (GnRH) and examined whether IL-6 stimulated their GnRH secretion. We demonstrated immunohistochemically that some of these neurons contained GnRH-like immunoreactivity. In primary cultures of these GnRH neurons, we found that the calcium ionophore A23187 stimulated GnRH secretion in a dose- and time-dependent manner. These hypothalamic cells secreted IL-6 spontaneously, producing about 10 ng/l in 24 h, and their IL-6 secretion was significantly stimulated by E2 at 10(-9)-10(-8) mol/l. This stimulatory effect was observed within 3 h. IL-6 also stimulated the release of GnRH in a dose- and time-dependent manner, and these effects of IL-6 were significantly blocked by anti-IL-6 antiserum. These results suggest that the central action of IL-6 on the GnRH neurons may be an important physiological event in the hypothalamus.
Yamaguchi
M
M
Department of Obstetrics and Gynecology, Osaka University Medical School, Japan.
Koike
K
K
Yoshimoto
Y
Y
Matsuzaki
N
N
Miyake
A
A
Tanizawa
O
O
D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D002478:Cells, Cultured; D004958:Estradiol / Q000494:pharmacology; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000378:metabolism*; D007031:Hypothalamus / Q000187:drug effects / Q000378:metabolism*; D007150:Immunohistochemistry; D015850:Interleukin-6 / Q000378:metabolism / Q000494:pharmacology*; D007700:Kinetics; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains
D015850:Interleukin-6; D007987:Gonadotropin-Releasing Hormone; D000001:Calcimycin; D004958:Estradiol