Effects of XW630 on cell proliferation, iNOS activity, and cGMP content inhuman osteoblast-like cell line TE85

AIM: To study the effects of 2-[3-estrone-N-ethyl-piperazine-methyl] tetrac ycline (XW630) in human osteoblast-like cell line TE85, METHODS: [H-3]Thymi dine incorporation and cell count for cell proliferation, radioimmunoassay for cyclic GMP (cGMP) content, and monitoring the conversion of [H-3]argini ne for inducible nitric-oxide synthase (iNOS) activity assay. RESULTS: Afte r treatment with XW630 for 48 h, [H-3]thymidine incorporation and cell numb ers increased by 62.7% and 96.9%, respectively. N-G-monomethyl-L-arginine ( L-NMMA, an NOS inhibitor) induced a concentration-dependent inhibitory effe ct on the proliferation after treatment for 48 h. The inhibitory effect was prevented partially by XW630 (1.0 nmol.L-1). After treatment with XW630 fo r 12 - 48 h, iNOS activity and cGMP concentration increased in time-depende nt manners. CONCLUSION: XW630 stimulated cell proliferation, enhanced iNOS activity and cGMP content in human osteoblast-like cell line TE85.