Pamidronate Disodium (CGP 23339AE) is a nitrogen containing bisphosphonate, used to prevent osteoporosis.
Pamidronate increases OPG mRNA levels and protein secretion by hOB by up to 2- to 3-fold in a dose-dependent fashion with a maximum effect at 1 ?M after 72 hours. Artemisinin prevents the inhibitory effects of the glucocorticoid dexamethasone on OPG mRNA and protein production. Pamidronate induces type I collagen secretion and alkaline phosphatase activity by 2-fold. [1] Pamidronate has a more pronounced calcium-lowering action than etidronate (etidronic acid) and clodronate (clodronic acid) and provides a longer period of normocalcaemic remission. [2] Pamidronate (APD) dose-dependently inhibits resorption of calcium phosphate films by equine OCLs with an IC(50) of 0.58 μM in one horse. Pamidronate also dose-dependently inhibits the number of OCLs present in BM cultures after 7 days. [3]
Pamidronate administration significantly suppresses this increase below the control level in the tibia and distal femur of oophorectomized rats. Pamidronate significantly increases bone density and ash weight in both sham-operated and oophorectomized rats. [4] Pamidronate inhibits all significant effects of growth hormone (GH) and it also decreases the IGF-I levels in rats treated with growth hormone (GH). Pamidronate itself results in increased the bone density and ash weight of the tibia and decreased urinary DPD excretion. [5]
[1] Viereck V, et al. Biochem Biophys Res Commun,?002, 291(3), 680-686. [2] Fitton A, et al. Drugs,?991, 41(2), 289-318. [3] Gray AW, et al. Res Vet Sci,?002, 72(2), 105-113.