Abstract
Objectives:
Recognize the differential expression of osteoprotegrin (OPG) in the otic capsule of adult male mice compared with other selected skeletal bones, both in nearby locations such as the temporal bone, and in distant bones, such as the tibia.
Methods:
The experimental study was conducted in 2011 on 20 normal adult male albino mice with average weight 50 to 60 g. Animal housing at the physiology department (Alexandria Faculty of Medicine) followed the rules of research ethics for experimental animals approved by Faculty of Medicine, University of Alexandria, Egypt. The following bone specimens were harvested from normal adult male albino mice by microdissection: (1) temporal bone, (2) otic capsule bone surrounding the cochlea, and (3) tibia and stained immunohistochemically for anti-OPG monoclonal antibody. Positive staining was graded and analyzed using image software that measured the staining intensity as units of pixels/microscopic field examined at 400 magnification. Quantitative data were described using mean, standard deviation, median, minimum and maximum. Comparison between different sites were analyzed using F-test (analysis of variance) and post hoc test (least significant difference) for pairwise comparison.
Results:
OPG was detected as a brown DAB chromogen staining of tissue components expressing a positive OPG monoclonal antibody immune reactivity. Statistical analysis of the results revealed that high OPG level concentrations were found in otic capsule followed by temporal bone and finally the tibia.
Conclusions:
The findings highlight the role of a OPG in inhibition of otic capsule remodeling.