OBJECTIVE: Evaluating bone site-dependent differences in the effect of thyroid dysfunctions on the femur and lumbar vertebrae of female rats. METHODS: Thirty-three 2-month-old female wistar rats were distributed in three groups: euthyroid (control), hypothyroid and hyperthyroid. Ninety days after treatment for hypothyroidism and hyperthyroidism induction, the female rats were euthanized; the blood was collected for free T4 dosage and the femurs and segment 1-3 of the lumbar vertebrae were decalcified and processed for analysis of the trabecular bone percentage. RESULTS: The hyperthyroid group showed significantly higher trabecular bone percentage in the femoral metaphysis, in comparison with the control group. But the hyperthyroidism group did not increase the trabecular bone percentage in the lumbar vertebrae. The hypothyroidism group significantly reduced the trabecular bone percentage in the lumbar vertebrae, but did not alter the trabecular bone percentage in the femur. CONCLUSION: The effect of hypothyroidism and hyperthyroidism on bone histomorphometry is different in each condition and bone site-dependent.
Hypothyroidism; Hyperthyroidism; Femur; Spine; Rats
