Abstract: AIM: To observe the protective effects of depside salt from salvia miltiorrhiza on temporomandibular joint under repeatedly high sustained +Gz condition. METHODS: 40 male Wistar rats were randomly dividedinto 5 groups.Group 1 was only fixed with rat kept devices for 5min as a negative group.Group 2 was borne +10 Gz for 5min repeatedly 5 times daily, 4 days per week, 3 weeks in total as a positive group.Groups 3-5 were repeatedly exposed +10 Gz same as positive group with depside salt from salvia miltiorrhiza at three different doses (1, 3, 10 mg/kg, i.m.respectively).Every rat was taken in depside salt from salvia miltiorrhiza or 0.9 % sodium chloride solution about 30min prior to the +Gz experiment.The morphological observation and c-fos mRNA expression of jugomaxillary muscle and joint discs were conducted by electronic microscope and RT-PCR technology.RESULTS: Repeatedly high sustained +Gz stresses was able to induce damage of temporomandibular joint, and depside salt from salvia miltiorrhiza could blunt abnormal changes of electronic microscope of temporomandibular joint under +Gz condition and inhibit c-fos mRNA expression.CONCLUSION: Depside salt from salvia miltiorrhiza has a protective effect on the damage of temporomandibular joint induced by repeatedly high sustained +Gz in rats.

Key words: depside salt from salvia miltiorrhiza, temporomandibular joint, high sustained gravity stress, rat