CASTRATION PREVENTS CALCIUM-CHANNEL BLOCKER-INDUCED GINGIVAL HYPERPLASIA IN BEAGLE DOGS

1 The purpose of this study was to investigate testosterone's role on the calcium channel antagonist oxodipine-inducing gingival hyperplasia in a dog model.2 Two experiments were conducted using castrated and i ntact male dogs. Oxodipine was administered orally for 90 days, at a d ose of 24 mg/kg/day. In the first experiment, the occurrence of gingiv al hyperplasia was evaluated. In the second, the gingival index (GI) a nd gingival hyperplasia index (GHI) were recorded and correlated with serum levels of testosterone. 3 A significant positive correlation bet ween GI, GHI and plasma testosterone was noted, Castrated dogs were in jected with testosterone, 4 months after the start of oxodipine treatm ent, while in the non-castrated dogs, administration of oxodipine was stopped. Castration correlated with lack of GH, while testosterone inj ection to the same dogs was associated with an increase of GI and GHI. 4 Since it is known that testosterone receptors are present in the gin giva, ii is proposed that oxodipine-induced gingival hyperplasia could be mediated by the calcium channel blocker on plasma testosterone lev els.