RESUMEN
Temporomandibular disorders (TMDs) predominantly affect women of reproductive ages, with pain as the main symptom. The aim of the present study was to examine the effects of 17ß-estradiol (E2) on glutamate-evoked hypernociception of masseter muscle and to examine whether genistein could antagonize the effects of E2 in female rats. Injection of glutamate into the masseter muscle dose-dependently decreased head withdrawal thresholds, a parameter for mechanical hypernociception. Head withdrawal thresholds in ovariectomized rats also decreased with increasing doses of E2 replacement, and were further aggravated by injection of glutamate (1M, 40µL) into the masseters. Genistein at doses of 7.5 and 15 mg/kg antagonized E2-induced hypernociception of masseter muscle, and at doses of 7.5, 15, and 30 mg/kg also antagonized E2 potentiation of glutamate-evoked hypernociception of masseter muscle. Genistein produced optimal antagonistic effects of E2 on nociception behavior at a dose of 15 mg/kg. On the molecular level, tyrosine phosphorylation of the NR2B subunit of the N-methyl-D-aspartate receptor (pNR2B) and phosphorylated mitogen-activated protein kinase (pERK1/2) were significantly upregulated in the hippocampus following glutamate injection and were further potentiated by E2 replacement. Genistein at dose of 15 mg/kg partially reversed E2-potentiated glutamate-evoked upregulation of pNR2B and pERK1/2 expression in the hippocampus. These results indicated that moderate doses of genistein could antagonize E2 enhanced glutamate-evoked hypernociception of masseter muscle possibly via N-methyl-D-aspartate receptor and ERK1/2 signaling pathways in the hippocampus.
RESUMEN
OBJECTIVE: To review the situation of stomatological research projects supported by National Natural Science Foundation of China (NSFC) and to analyze the status of stomatological research and obtained achievements in the past decade. METHODS: The internet-based science information system of NSFC together with Yearbook of Chinese Stomatology was served as the basis of data collection. All of the data were arranged and analyzed by Excel. RESULTS: A total of 866 projects and 234.4054 billion Yuan were supported by NSFC during the past decade, and they were increasing continuously. The average supportive strength of each single project was also enhanced. The percentage of projects supported by the NSFC for young scientists accounted for the biggest proportion. The approved projects of stomatology were covering an increasingly wide area of the subjects. The projects number of different areas kept growing, and further investigations were done in these projects. The areas number were from 10 increasing to 26. CONCLUSIONS: With the support of NSFC, great progress has been made in stomatology, and the interdisciplinary research between stomatology and other disciplines is more active.