Reduction of bone loss by denbufylline, an inhibitor of phosphodiesterase 4.
The effects of denbufylline, a xanthine derivative with selective inhibitory activity on the phosphodiesterase (PDE) 4 isoenzyme, on bone loss in Walker 256/S-bearing rats and on mineralized nodule formation and osteoclastlike cell formation in bone marrow culture systems were examined. Serial oral administrations of denbufylline inhibited the decrease in the bone mineral density of femurs from Walker 256/S-bearing rats, without influence on the healthy rats. Denbufylline restored the bone mass and the number of osteoclasts and osteoblasts per trabecular surface in the femur metaphysis. Among PDE inhibitors, only PDE4-selective inhibitors increased the number of mineralized nodules and decreased the number of osteoclastlike cells in the in vitro bone marrow culture systems, and dibutyryl cyclic AMP mimicked these effects in the in vitro systems. These results suggest that the PDE4 isoenzyme may play an important role in bone turnover through cyclic AMP and that its inhibitors are candidates for therapeutic drugs for the bone loss diseases.
Miyamoto
K
K
Department of Pharmacology and Pharmaceutics, Graduate School of Pharmaceutical Sciences, Kanazawa University, Japan.
Waki
Y
Y
Horita
T
T
Kasugai
S
S
Ohya
K
K
D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D015105:3',5'-Cyclic-AMP Phosphodiesterases; D012368:4-(3-Butoxy-4-methoxybenzyl)-2-imidazolidinone / Q000494:pharmacology; D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology / Q000187:drug effects; D001862:Bone Resorption / Q000209:etiology / Q000473:pathology / Q000517:prevention & control*; D003994:Bucladesine / Q000494:pharmacology; D002113:Calcification, Physiologic / Q000187:drug effects / Q000502:physiology; D002279:Carcinoma 256, Walker / Q000150:complications / Q000473:pathology / Q000503:physiopathology*; D002478:Cells, Cultured; D054703:Cyclic Nucleotide Phosphodiesterases, Type 4; D005260:Female; D051379:Mice; D020105:Milrinone; D010010:Osteoclasts / Q000166:cytology* / Q000187:drug effects; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology*; D010727:Phosphoric Diester Hydrolases / Q000378:metabolism*; D011688:Purinones / Q000494:pharmacology; D011728:Pyridones / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D014970:Xanthines / Q000494:pharmacology*
D010726:Phosphodiesterase Inhibitors; D011688:Purinones; D011728:Pyridones; D014970:Xanthines; C043898:denbufylline; D012368:4-(3-Butoxy-4-methoxybenzyl)-2-imidazolidinone; D003994:Bucladesine; D010727:Phosphoric Diester Hydrolases; D015105:3',5'-Cyclic-AMP Phosphodiesterases; D054703:Cyclic Nucleotide Phosphodiesterases, Type 4; C011145:zaprinast; D020105:Milrinone; D015056:1-Methyl-3-isobutylxanthine