Abstract
Several clinical studies have described gingival hypeplasia induced by nifedipine administration.
The purpose of this study was to investigate the effect of nifedipine on granulomas caused by cotton pellets implanted in the backs of 60 Wistar rats. Nifedipine was administered at a dose of 100 mg/kg daily starting 24 hours after cotton pellet implantation for the following periods; 1) 1 weeks (1 week group), 2) 2 weeks (2 week group) 3) 4 weeks (4 week group), in another group, preparatory administration was carried out for 4 weeks before implantation, and continued for 4 weeks after the treatment (preparatory group). A control group was assigned for each group, to which no drug was administered. At the end of the period, the rats were sacrificed, granulomas were removed and their wet weight and protein and hydroxyprolyne contents were determined. Histological features were also observed.
Wet weight and protein contents were increased during the first week and maintained for 4 weeks in both the nifedipine-administered and control groups.
Hydroxyprolyne contents were increased gradually in each period, and were also significantly increased in all the nifedipine-administered groups, except at 1 week, compared with each control group. Hydroxyprolyne was significantly increased in the preparatory group compared with both the 4 week administered and control groups.
Histologically, apparent invasion of inflammatory cells and generation of collagen fibers within the granulomas were seen after each period. Especially thick collagen bundles were observed in the 4 week administered and preparatory groups.
