ABSTRACT
Myocardial fibrosis (MF) is the result of persistent and repeated aggravation of myocardial ischemia and hypoxia, leading to the gradual development of heart failure of chronic ischemic heart disease. Triptolide (TPL) is identified to be involved in the treatment for MF. This study aims to explore the mechanism of TPL in the treatment of MF. The MF rat model was established, subcutaneously injected with isoproterenol and treated by subcutaneous injection of TPL. The cardiac function of each group was evaluated, including LVEF, LVFS, LVES, and LVED. The expressions of ANP, BNP, inflammatory related factors (IL-1β, IL-18, TNF-α, MCP-1, VCAM-1), NLRP3 inflammasome factors (NLRP3, ASC) and fibrosis related factors (TGF-β1, COL1, and COL3) in rats were dete cted. H&E staining and Masson staining were used to observe myocardial cell inflammation and fibrosis of rats. Western blot was used to detect the p-P65 and t-P65 levels in nucleoprotein of rat myocardial tissues. LVED and LVES of MF group were significantly upregulated, LVEF and LVFS were significantly downregulated, while TPL treatment reversed these trends; TPL treatment downregulated the tissue injury and improved the pathological damage of MF rats. TPL treatment downregulated the levels of inflammatory factors and fibrosis factors, and inhibited the activation of NLRP3 inflammasome. Activation of NLRP3 inflammasome or NF-κB pathway reversed the effect of TPL on MF. Collectively, TPL inhibited the activation of NLRP3 inflammasome by inhibiting NF-κB pathway, and improved MF in MF rats.
ABSTRACT
BACKGROUND: Currently, acid etching and bonding technology have been widely used in clinical stomatology. Data have indicated that the main content of inorganic elements (calcium and phosphorus) has a certain difference between the dental enamel and dentin of the young and adult permanent teeth. OBJECTIVE:To measure the content of main inorganic elements, calcium and phosphorus, in the dental enamel and dentin from young and adult permanent teeth with spectrophotometry and ethylene diamine tetraacetie acid titration method. METHODS:Each 20 adult and young permanent teethin vitrowere selected. Plaster stone and water was mixed; when it was nearly dried, the teeth were verticaly cast in the mixture and the tooth surface was exposed. The models were cut into the slices using syj-200 precision cutting machine, and then the slices were put into nitric acid and dissolved through heater to prepare standard solution. At last, the concentrations of calcium and phosphorus in the hard tissue of both young and adult permanent teeth were measured with spectrophotometric method and titration method. RESULTS AND CONCLUSION:The content of calcium and phosphorus and calcium/phosphorus ratio in the hard tissue of young permanent teeth were less than those of adult permanent teeth (P < 0.05), reflecting that the organic matter content was more than that in adult permanent teeth, but their mineralized degree was inferior to that of adult permanent teeth (P < 0.05). These findings indicate that the young permanent teeth are more acid proof than the adult permanent teeth; therefore, the acid etching time can be properly prolonged for young permanent teeth in clinical treatment, in order to achieve better effects.