Tobacco extract but not nicotine impairs the mechanical strength of fracture healing in rats

摘要: The influence of nicotine and tobacco extract (without nicotine) alone in combination on mechanical strength closed femoral fractures rats was investigated. One hundred four male Sprague-Dawley were divided into groups receiving: nicotine, extract, plus saline. week prior to fracture, osmotic pumps implanted subcutaneously all animals administer equivalent the serum level observed a smoker consuming one two packs cigarettes daily. An volume saline administered control animals. Tobacco orally. A transverse diaphysial fracture performed, stabilized with an intramedullary pin. mechanically tested after 21 days healing. decreased strength. Ultimate torque at yield point group by 21% (p = 0.010) 23% (p = 0.056), respectively, compared vehicle (saline) group, 20% (p = 0.023) 26% (p = 0.004), group. No difference found between groups. 18% (p = 0.013) reduction differences ultimate stiffness, energy absorption, callus bone mineral content line any Serum levels 40–50 ng/mL given (equivalent persons smoking per day). © 2006 Orthopaedic Research Society. Published Wiley Periodicals, Inc. J Orthop Res 24:1472–1479,