A Trial Study of Propranolol and Zhigancao Decoction on the Central Depressant and Anti-osteoporosic Action in Ovariectomized Rats

ObjectiveThis study was originally designed to observe the effects of propranolol (a β-blocker) and Zhigancao Decoction (ZGCD) on bone mass in ovariectomized rats.MethodsThirty-eight female Sprague-Dawley rats were divided into four groups initially, a sham-operated group (Sham, n=7), a model ovariectomized (OVX) group (Model, n=7), a propranolol group (Pro, n=12) and a ZGCD group (ZGCD, n=12). After 15 weeks of treatment, the expected effects were not found. In order to verify the situations of the experiment, we modified the study by administering calcitonin to a subgroup of the tested Pro and ZGCD rats.ResultsThe Pro and ZGCD treatments showed decreased heart rate and plasma norepinephrine level, but neither an increased bone mass nor any bone metabolism differences from the model rats were found. However, the OVX-induced bone loss was prevented by the sequent treatment of calcitonin.ConclusionsThe results provide no evidence that the β-blocker propranolol may stimulate bone formation, and do not justify its use for clinical treatment of osteoporosis.