Protein kinase C inhibitor H-7 blocks effects of tumor necrosis factor on bone cells.
OBJECTIVE
To study the effects of tumor necrosis factor (TNF) on the neonatal mouse osteoblast-enriched calvarial cells and effects of protein kinase C (PK C) inhibitor, 1-(5-isoquinolinesulfonyl)-2 -methylpiperazine (H-7) on the TNF actions.


METHODS
[3H]TdR uptake by the osteoblasts was used to measure cell proliferation. Cellular alkaline phosphatase (AIP) and tartrate resistant acid phosphatase (trAcP) activities were determined spectrophotometrically.


RESULTS
TNF (1-100 kU . L-1) inhibited both proliferation and expression of AIP activity, but stimulated trAcP activity. These TNF-induced actions were blocked by simultaneous addition of H-7 (5-20 mumol . L-1).


CONCLUSIONS
TNF has potent effects on the osteoblasts, and the blockade of TNF actions by H-7 suggests that TNF exert its effects through PK C.
Wu
T M
TM
Research Laboratory of Natural and Synthetic Drugs, School of Pharmacy, Second Military Medical University, Shanghai, China.
Zhang
J P
JP
Hu
Z L
ZL
Qian
D H
DH
D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine / Q000494:pharmacology*; D000135:Acid Phosphatase / Q000378:metabolism; D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D000831:Animals, Newborn; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D051379:Mice; D008813:Mice, Inbred ICR; D010006:Osteoblasts / Q000166:cytology* / Q000201:enzymology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors*; D012886:Skull / Q000166:cytology; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors*
D004791:Enzyme Inhibitors; D014409:Tumor Necrosis Factor-alpha; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D011493:Protein Kinase C; D000469:Alkaline Phosphatase; D000135:Acid Phosphatase