The Effects of 2-Aminoethoxydiphenyl Borate (2-APB) and Dantrolene on Rat Bones Treated With NaAsO2

Objective To observe the effects of arsenic and the protective effects of 2-aminoethoxydiphenyl borate (2-APB) and dantrolene on the trabeculae of Sprague Dawley (SD) rats. Methods Thirty-six SD rats were randomly divided into a control group and an arsenic poisoning group. After 12 weeks of arsenic exposure, six rats in the arsenic poisoning group were randomly selected for sacrifice. The remaining rats were randomly assigned to four groups (n=6 per group): natural recovery after arsenic exposure, dantrolene intervention after arsenic exposure, 2-APB intervention after arsenic exposure, and 2-APB + dantrolene intervention after arsenic exposure. After 21 days of treatment by oral gavage every other day, the bilateral femurs and tibias of the rats were scanned using micro-computed tomography (micro-CT). Bone marrow stromal cells (BMSCs) were isolated and cultured, and Ca2+ concentration and alkaline phosphatase (ALP) activity of BMSCs was assessed. Results Compared with the control group, bone mineralization density (BMD), bone volume (BV)-to-total volume (TV) ratio (BV/TV), trabecular number (Tb.N), trabecular thickness (Tb.Th), and degree of anisotropy (DA) decreased, while trabecular separation (Tb.Sp), trabecular pattern factor (TBpf), and structural model index (SMI) increased in the arsenic poisoning group (P<0.05); additionally, Ca2+ concentration increased and ALP activity decreased significantly in the arsenic poisoning group (P<0.05). Compared with the natural recovery group, after arsenic exposure, the indices of micro-CT recovered to some extent, the Ca2+ concentration of BMSCs decreased significantly, and the ALP activity of BMSCs increased significantly after intervention with 2-APB and dantrolene (P<0.05). Conclusion Arsenic can lead to significant changes in the structure of trabeculae and osteoporosis in rats, and these changes can be improved by intervention with 2-APB and dantrolene.

The influence of 2-aminoethoxydiphenyl borate on the electrical activity of the rat heart under hypoxia/reoxygenation conditions

The aim of the study was to apply the multi-electrode mapping method to investigate the effect of 2-aminoethoxydiphenyl borate (2-apb) on the electrical activity and vessels of the isolated rat heart under hypoxia/reoxygenation injury (H/R). To date, the ability to influence on the calcium currents and condition of gap junctions has been shown for 2-apb. Changes in the intracellular calcium concentration in the heart play the pivotal role in the development of H/R.As a result, it was shown that 2-apb influences on the myocardial conduction velocity, sinus rhythm and coronary blood flow in the isolated rat heart. 2-apb caused heart fibrillation during normoxia but not under hypoxia, and attenuated the effect of the H/R on heart rate and vascular function.