OF CALCITONIN RECEPTOR
IN THE RAT TEMPORO – MANDIBULAR JOINT STRUCTURES
Kaklamanos 1,2, Theodora Papamitsou 1,
Louise Economou 1, Antonia Sioga 1,
of Histology & Embryology, Medical School, Aristotle University
of Thessaloniki, Thessaloniki,
of Orthodontics, Dental School, Aristotle University of Thessaloniki,
INTRODUCTION. Calcitonin is a
natural peptide hormone produced by parafollicular cells (C-cells) in
the thyroid gland. Binding of low concentrations of calcitonin to the
calcitonin receptor on osteoclasts induces a rapid change in the
cytoskeletal structure of the osteoclasts in vitro, which in turn leads
to a reduction in bone resorption. Furthermore, calcitonin has been
recently shown to possess regulatory actions on cartilage and
subchondral bone, which may cause long-term clinical benefits. The aim
of this study is to investigate the expression and localization of
calcitonin receptor in the rat temporomandibular joint structures.
Forty-eight 21-day-old male Wistar rats were housed in well-ventilated
stainless cages with 12-hour light-dark cycle and a maximum of 3 rats
per cage. The rats were provided food and water ad libitum. Six animals
were sacrificed every time at days 3, 7, 10, 14, 17, 21, 24, 28. The
right temporomandibular joints were dissected, fixed (10% neutral
formalin for 24 h), demineralised (10 days in 5% formic acid),
embedded in paraffin (4-μm thick sections) and processed for
immunohistochemical staining of the calcitonin receptors. The protocols
were approved by the appropriate University committee.
Immunoexpression of calcitonin receptors was evident intensively around
the bony cavities and mildly in some muscle fibers.
Calcitonin receptors are expressed in the bony and muscle structures of
the rat temporomandibular joint. The physiologic importance of
calcitonin receptor expression for the development of the region
remains to be clarified.
KEY WORDS: calcitonin,
receptor, rat, temporomandibular joint.