Evidence that folliculo-stellate cells mediate the inhibitory effect of Japanese kampo medicine, unkei-to, on growth hormone secretion in rat anterior pituitary cell cultures.
OBJECTIVE
Cytokine-induced neutrophil chemoattractant (CINC) was reported to influence anterior pituitary hormone release. We recently found that Unkei-to, one of the Japanese Kampo medicines, stimulated CINC secretion by rat anterior pituitary cells and the pituitary folliculo-stellate (FS)-like cell line (TtT/GF). Therefore, the effect of Unkei-to on growth hormone (GH) secretion by rat anterior pituitary cells was investigated.


METHODS
Dispersed normal anterior pituitary cells, the folliculo-stellate-like cell line TtT/GF, and the GH3 cell were used to test the effect of Unkei-to on GH secretion. In reconstitutive coculture experiments, TtT/GF cells were mixed with GH3 cells at a ratio (TtT/GF cells: GH3 cells) of 1:99. From this mixture, cells were seeded onto plates at a density of 10(4) cells/well and were cultured for 5 days. The cells were then used in the experiments.


RESULTS
Unkei-to at 20 micrograms/ml significantly inhibited GH secretion by normal anterior pituitary cells within 12 hr of incubation. In contrast Unkei-to stimulated GH secretion by GH3 cells in a time- and dose-dependent manner, suggesting that an accessory cell type was involved. To assess the contribution of CINC as a paracrine factor, an experiment using a reconstitutive coculture system was performed, and Unkei-to was found to inhibit GH secretion when GH3 cells were cocultured with TtT/GF cells. The addition of anti-CINC antibody to the reconstitutive coculture system antagonized Unkei-to-inhibited GH secretion.


CONCLUSIONS
CINC, which was secreted from FS cells by Unkei-to, may be responsible for mediating the inhibitory effect of Unkei-to on GH secretion by rat anterior pituitary cells.
Koike
K
K
Department of Obstetrics and Gynecology, School of Medicine, Kanazawa University, Ishikawa, Japan.
Zhang
Z X
ZX
Sakamoto
Y
Y
Miyake
A
A
Inoue
M
M
D000818:Animals; D002478:Cells, Cultured; D019743:Chemokines, CXC; D002630:Chemotactic Factors / Q000494:pharmacology; D018920:Coculture Techniques; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D005260:Female; D013006:Growth Hormone / Q000378:metabolism*; D006131:Growth Inhibitors / Q000494:pharmacology; D006133:Growth Substances / Q000494:pharmacology; D036341:Intercellular Signaling Peptides and Proteins; D010903:Pituitary Gland, Anterior / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar
D019743:Chemokines, CXC; D002630:Chemotactic Factors; D004365:Drugs, Chinese Herbal; D006131:Growth Inhibitors; D006133:Growth Substances; D036341:Intercellular Signaling Peptides and Proteins; C058415:unkei-to; D013006:Growth Hormone