ABSTRACT
Experimental animal models of bone cancer pain have emerged and findings have provided a unique glimpse into unraveling the mechanism that drives this debilitating condition. Key contributors to the generation and maintenance of bone cancer pain are tumor-induced osteolysis, tumor itself, and production of nociceptive mediators in the bone-tumor microenvironment.
Subject(s)
Bone Neoplasms/complications , Pain/complications , Pain/physiopathology , Animals , Bone Neoplasms/therapy , Disease Models, Animal , Humans , Models, Biological , Neurochemistry , Pain ManagementABSTRACT
Radiotherapy is the cornerstone of palliative treatment for primary bone cancer in animals and metastatic bone cancer in humans. However, the mechanism(s) responsible for pain relief after irradiation is unknown. To identify the mechanism through which radiation treatment decreases bone cancer pain, the effect of radiation on mice with painful bone cancer was studied. Analysis of the effects of a 20-Gy treatment on localized sites of painful bone cancers was performed through assessments of animal behavior, radiographs and histological analysis. The findings indicated that radiation treatment reduced bone pain and supported reduced cancer burden and reduced osteolysis as mechanisms through which radiation reduces bone cancer pain.
Subject(s)
Femoral Neoplasms/pathology , Femoral Neoplasms/radiotherapy , Osteolysis/pathology , Osteolysis/radiotherapy , Pain/diagnosis , Pain/radiotherapy , Recovery of Function/radiation effects , Animals , Behavior, Animal/radiation effects , Bone Neoplasms/complications , Bone Neoplasms/pathology , Bone Neoplasms/radiotherapy , Femoral Neoplasms/complications , Male , Mice , Mice, Inbred C3H , Neoplasm Staging , Neoplasm Transplantation , Osteolysis/etiology , Pain/etiology , Pain Measurement/methods , Palliative Care/methods , Treatment OutcomeABSTRACT
These experiments explored the effects of non-contact exposure to two rodent species (rats and gerbils) on the defensive behaviors of male CD-1 mice. In Experiment 1 it was found that rats evoked substantial levels of defensiveness which were positively related to increases in rat activity. This effect was considerably attenuated, but still detectable, 30 min after rat exposure (Experiment 2). In Experiment 3 the effectiveness of rats and gerbils were compared. Gerbils were found to evoke a more modest increase in defensiveness than rats. These experiments indicate that non-contact exposure to rodents displaying varying levels of activity and, perhaps, propensity for predatory behavior provide a useful level of experimental control over the intensity of fear-like responses.
