Kawase T, Orikasa M, Suzuki A
Department of Pharmacology, Niigata University School of Dentistry, Japan.
Bone Miner. 1990 Nov;11(2):163-75. doi: 10.1016/0169-6009(90)90056-l.
The RDP 4-1 cell line was established from isolated rat dental pulp and cloned with limiting dilution in 96-multiwell plates. Despite their fibroblast-like appearance, RDP 4-1 cells required more than 5% (v/v) heat-inactivated fetal calf serum to maintain the cell growth and function. Type I collagen, but not type II and type III collagen, was immunocytochemically detected in the cells in subconfluent cultures. Prostaglandin E2 (PGE2, 5 ng/ml-5 micrograms/ml) dose-dependently increased cAMP accumulation, while prostaglandin F2 alpha (PGF2 alpha, 5 micrograms/ml) slightly increased it, in the presence of 0.1 mM isobutylmethyl xanthine. PGE2 (5 ng/ml-5 micrograms/ml) also stimulated phosphoinositide hydrolysis to produce inositol phosphates (IPs) in a time- and dose-dependent manner in the presence of 10 mM LiCl. PGF2 alpha was a more potent stimulator of phosphoinositide hydrolysis. Both prostaglandins increased cytoplasmic free calcium, independent of the level of extracellular calcium. Prolonged exposure (48 h) of the cells to PGE2 at higher concentrations (greater than or equal to 0.5 micrograms/ml) increased DNA synthesis. In these RDP 4-1 cells, thus, PGE2 receptors appeared to be associated with both cAMP and IPs-Ca2+ signaling systems, and that PGF2 alpha receptors are poor stimulators of the former but more potent ones of the latter. Our results suggest that both prostaglandins have some roles in regulating dental pulp metabolism.
RDP 4-1细胞系源自分离的大鼠牙髓，并在96孔板中通过有限稀释法进行克隆。尽管RDP 4-1细胞呈现成纤维细胞样外观，但维持细胞生长和功能需要超过5%（v/v）热灭活胎牛血清。在亚汇合培养的细胞中，免疫细胞化学检测到I型胶原蛋白，但未检测到II型和III型胶原蛋白。在存在0.1 mM异丁基甲基黄嘌呤的情况下，前列腺素E2（PGE2，5 ng/ml - 5 μg/ml）呈剂量依赖性增加cAMP积累，而前列腺素F2α（PGF2α，5 μg/ml）则使其略有增加。在存在10 mM LiCl的情况下，PGE2（5 ng/ml - 5 μg/ml）还以时间和剂量依赖性方式刺激磷酸肌醇水解以产生肌醇磷酸（IPs）。PGF2α是磷酸肌醇水解的更有效刺激剂。两种前列腺素均增加细胞质游离钙，与细胞外钙水平无关。细胞长时间（48小时）暴露于较高浓度（大于或等于0.5 μg/ml）的PGE2会增加DNA合成。因此，在这些RDP 4-1细胞中，PGE2受体似乎与cAMP和IPs - Ca2+信号系统相关，而PGF2α受体对前者的刺激较弱，但对后者的刺激更强。我们的结果表明，两种前列腺素在调节牙髓代谢中都具有一定作用。
