1.Characterization of the antagonistic effect on α1-adrenoceptor of the Chinese herb medicine Xiao Long Tong Bi
Zhizhen LU ; Yinzeng LI ; Qide HAN ; Jinming JIA
Journal of Peking University(Health Sciences) 2001;33(2):157-159
Objective: To better understand the antagonistic effect of Xiao Long Tong Bi (XLTB), a Chinese herb medicine, on α1-adrenoceptor (α1-AR). Methods: (1) Radio ligand binding assay . Specific 125I-BE2254(2-β(4-hdroxyphenyl)-ethyl amino-methyl-tetralone) binding was measured by incubating membrane of canine cerebral cortex with a single concentration of 125I-BE2254 in the presence of 15 concentrations of XLTB. Half-effectual concentration of inhibition (IC50) and Hill coefficients (nH) were determined by Hill plots. (2) Contractile responses of rat prostate strip in vitro were determined. pKB values for XLTB in competitively inhibiting NE-stimulated contraction of tissues were measured by the method of Ainlakshana. Results: XLTB competitively inhibited binding of 125I-BE2254 to α1-AR in a concentration -dependent manner. IC50 values for XLTB in canine cerebral cortex were (34.0±6.0) g*L-1, the Hill efficiency value (0.7±0.1) was significantly decreased from unity. Contractile studies showed that XLTB competitively antagonized the NE concentration-response curve with pKB values of (37.0±11.0) g*L-1 or (30.0±8.0) g*L-1 when XLTB concentration was 70 g*L-1 or 170 g*L-1, respectively. The pKB values for XLTB in antagonizing NE-induced contraction of tissues were showed to fit in well with the IC50 values on rat prostate. Conclusion: These results suggest that XLTB appears to be a competitive antagonist for α1-AR.
2.Biomechanical Characteristics Analysis of Human-Machine Coupling on Ankle
Yongsheng SU ; Zongxing LU ; Yinzeng LI ; Xiaohui CHEN ; Dongzhe ZHAO
Journal of Medical Biomechanics 2023;38(2):E389-E395
Objective A 2-PSU/ RR parallel ankle rehabilitation robot was designed, and the biomechanical properties of human muscles were also analyzed, so as to study rehabilitation strategy of the ankle rehabilitation robot. Methods The actual workspace of the robot was obtained by numerical discrete search method, and the effect of structural parameter changes on the height of robot moving platform was explored. Then the human biomechanical responses such as muscle force and muscle mobility were obtained by human biomechanical simulation software AnyBody, so as to investigate the effect of moving platform height changes on muscle behavior. Results The robot could meet the demand of ankle plantarflexion/ dorsiflexion and inversion/ eversion motion. Appropriately increasing the initial inclination angle and decreasing the length of the fixed-length bar enabled the ankle rehabilitation robot to have a lower overall height. The height of the moving platform was decreased by 10 mm in turn, and the muscle force and muscle activity of the human body involved in the movement were decreased to a certain extent. Conclusions This study provides a new design solution for ankle rehabilitation, offers theoretical guidance for motion analysis of the ankle rehabilitation robot, and accelerates rehabilitation of the patients’ ankles by modifying the mechanism parameters.