Renewal and migration of rat incisor mesenchymal cells after doxorubicin administration

Abstract

Ten female rats were intravenously injected with doxorubicin (20 mg/kg) and divided into two equal groups receiving a dose of tritiated thymidine either simultaneously with doxorubicin or 1 h before being killed after 5 days. Six control animals were correspondingly injected with 3H-thymidine. The left and right maxillary incisors were prepared for histologic and microautoradiographic investigation, respectively. The distribution of labeled cells in animals injected 1 h before death showed the regions of proliferation, whereas migration from these regions was evaluated by longer observation time. A zone of reduced dentin deposition lined by irregular odontoblasts being young odontoblasts and late preodontoblasts was observed at the time of doxorubicin injection. Pulpally to the dentinal lesion, islands of irregular predentin were deposited by non-progenitive pulp cells and depolarized odontoblasts. The late preodontoblasts were renewed from progenitive pulp cells, leading to a disturbed mantle predentin deposition.

Histopathological Study of Time Course Changes in PTHrP-Induced Incisor Lesions of Rats

“…Since the lesion was observed only after incisal fractures and long sustained high PTHrP concentration, the lesion is neither the cause of the fracture, nor the early response to the high PTHrP concentration of this model. Additionally, the lesion was identical to those occurring in response to the treatment with several cytotoxic agents, and considered to be the reparative response to the preceding cytotoxic effect of those agents, which restricted to certain susceptible populations of the odontoblasts (Adkins, 1972;Koppang, 1973;Adatia, 1975;Mikkelsen, 1978;Koppang, 1976, 1980;Stene, 1978Stene, , 1979Nogueira et al, 1981;Dahl, 1984Dahl, , 1985Karim and Eddy, 1984;Dahl and Koppang, 1985;Moule et al, 1993). According to the accumulating knowledge of PTHrP, it is not known as a cytotoxic agent but as one of the factors related to the reparative response in several tissues (Ferguson et al, 1998;Vortkamp et al, 1998;Blomme et al, 1999;Kudo et al, 2000;Nakase et al, 2001;Okazaki et al, 2003).…”

Evaluation of rat incisor mesenchymal cells in bleomycin injected animals fixed by immersion or perfusion

“…These cells differ from the bleomycin sensitive non-cycling cell like non-cychng cells of a proliferating cell population (6) and cultured cells reaching a plateau phase (22) in that they are irreversible postmitotic cells. Mitoses and incorporation of thymidine are never found in odontobiasts and scarcely ever in non-progenitive pulp cells (7,9), even after pulp destruction (25).…”

Child cancers: managing the complications of childhood chemotherapy in the adult dentition

“…5 The effects of other chemotherapeutic agents, such as vincristine, vinblastine, and doxorubicin in animal studies were found to cause dental abnormalities similar to those in cyclophosphamide. 6,7 Should a group of ameloblasts become disturbed, the resultant enamel secreted at that precise time may be defective or hypoplastic. In cases of more severe disturbance, the whole tooth may fail to form.…”