Objective: The aim of this study was to evaluate the bone healing in spontaneously hypertensive rats (SHR) and compare the results with normotensive rats, evaluating male and female animals.Methods: A bone drill defect was created in the left femur of 24 SHR (12 males and 12 females) and 24 normotensive rats (12 males and 12 females). The animals were divided into two groups and sacrificed 7 and 21 days after the surgical procedure. After the routine laboratory processing, histological and histometric analysis were carried out and data were submitted to ANOVA and Tukey's test (5%).Results: Males and females from the same group had similar histological characteristics. After seven days, all animals presented irregular bone trabeculae. The periosteal osteoblasts were flattened in SHR, and presented a cuboid shape in normotensive animals. After 21 days, the bone defects of all specimens showed a linear closure in all the superficial extension. In addition, SHR presented flattened osteoblasts surrounding the bone trabeculae, while normotensive ones showed cuboidal cells. Statistical analysis of the histometric data indicated similar means between the male and female groups, except for normotensive rats on day 7. In addition, a larger amount of new bone formation was observed in hypertensive when compared to normotensive rats on day 21, in males as well as females.
Conclusion:We conclude that bone healing in SHR was more significant than in normotensive ones, as shown by the histological and histometric evaluation 21 days after surgery.Key words: Femur/abnormalities, hypertension, rats, inbred (SHR). Systemic arterial hypertension is one of the most important world's health problems. Some bone pathologies may be aggravated in hypertensive individuals due to their pattern of calcium regulation, which induces bone loss in hypertensive human individuals 1-3 as well as in spontaneously hypertensive rats (SHR) [4][5][6] . Thus, bone mineral density (BMD) is reduced in hypertensive humans 1-3 and in SHR [4][5][6] , when compared to normal normotensive controls.Despite the possibility that this pathology can affect both sexes, most experimental studies were carried out in male rats. Liang et al 7 stated that more detailed investigations of bone behavior in female rats were necessary, due to the fact that, in humans, osteoporosis is more prevalent in women than in men.The connection between hypertension and bone metabolism is evident; however, the process of bone repair in hypertensive individuals is little known. Hence, the aim of this study was to evaluate, histological and histometrically, the process of bone repair in SHR of both sexes, comparing the results to those obtained from normotensive animals.
MethodsThis study was approved by the Ethics Committee of the Institution (Protocol # 051/2002 PA/CEP).A monocortical bone defect (2mm) was created in the local of largest diameter in the proximal region of the left femur diaphysis of 48 rats (24 hypertensive and 24 normotensive rats). Seven days after the surgery, 12 norm...
