RESUMEN
Objective To investigate the effects of Jinqi Zhizhu Decoction (JQZZD) on gastric motility of GK rats with diabetic gastroparesis (DGP); To discuss its mechanism of action. Methods 12 out of 80 male GK rats were randomly selected as normal group, and others were induced to be DGP model by irregular feeding with high sugar and high fat diet for 8 weeks. The model rats were randomly divided into model group, positive medicine group, JQZZD low-, medium-, and high-dose groups. All rats were given continuous intragastric administration for 12 weeks. The residual rate of pigment in stomach was detected and calculated. The concentration of DA, ACh and 5-HT in plasma were detected by ELISA. The morphological changes of gastric antrum were observed by HE staining. The ultrastructure of mucous layer of gastric antrum was observed by transmission electron microscope. The protein expressions of Rho A, ROCK1 and ROCK2 were detected by Western blot. Results Compared with normal group, the residual rate of pigment in model group increased, while DA, ACh and 5-HT, relative amount of protein expressions of Rho A, ROCK1 and ROCK2 decreased (P＜0.01). Compared with model group, the residual rate of pigment in positive medicine group and JQZZD high-dose group decreased, while DA, ACh and 5-HT, relative amount of protein expressions of Rho A, ROCK1 and ROCK2 increased (P＜0.05, P＜0.01), and morphological changes and ultrastructure of mucous layer obviously improved. There was no significant differences in the residual rate of pigment, DA content and protein expressions of Rho A, ROCK1 and ROCK2 between positive medicine group and JQZZD high-dose group (P＞0.05). Compared with JQZZD low-dose group, the residual rate of pigment in JQZZD high-dose group decreased, while DA, ACh and 5-HT, relative amount of protein expressions of Rho A, ROCK1 and ROCK2 increased (P＜0.05, P＜0.01). Conclusion JQZZD may improve gastric motility, promote gastric emptying, and improve and repair damage of mucous membrane in the gastric antrum. All of these may be related to regulating protein expressions of Rho A/ROCK signal pathway.
RESUMEN
Neuronal differentiation is a complex biological process accompanying cytoskeletal reorganization, including neurite outgrowth and growth cone formation. Therefore, neuronal differentiation is critically regulated by actin-related signaling proteins, such as small Rho GTPases, guanine nucleotide exchange factors (GEFs), and myosins. This study will demonstrate the change in activity of three small Rho GTPases, Rac, Cdc42, and Rho A, by treatment with blebbistatin (BBS), a specific inhibitor for myosin, during bFGF-induced neurite outgrowth in PC12 cells. Treatment with BBS induced morphological changes in growth cones and neurites during differentiation. A marked increase in protrusion and filopodia structures in growth cones, the shaft of neuritis, and cell membranes was observed in the cells treated with BBS. Activity of Rho GTPases showed the alterations in response to BBS. Activities of both Rac and Rho A were inhibited by BBS in a time-dependent manner. By contrast, Cdc42 activity was not changed by BBS. These results suggest that inactivation of myosin II by BBS induced morphological changes in neurites and growth cones and distinct regulation of three Rho GTPases during differentiation of PC12 cells.