Protection of SAM on KCl-injured primary cultured neurons via reducing Cav-1 expression / 中国药理学通报

Aim To investigate the protective effects of S-adenosylmethionine (SAM)on KCl-stimulated pri-mary cultured neurons and the potential mechanism. Methods The primary cultured cortical neurons were randomly divided into three groups:normal (Con) group,KCl group and SAM-KCl group. The changes of cell morphology were observed by microscope,and the mRNA and protein expression levels of caveolin-1 (Cav-1)in each group were detected by qPCR and Western blot. Results After treated with 0. 05 mol· L - 1 KCl for 12 hours,the primary cultured neurons showed morphological injury,shortening of neurites, reduction of soma mass and accumulation of cells. While neurons pretreated with 0. 02 mol·L-1 SAM for 6 hours could significantly reduce the damage induced by KCl. qPCR and Western blot analysis showed that SAM could reduce the neurons expression of Cav-1 mRNA and protein that induced by KCl. Conclusion SAM can protect neurons from the damage induced by KCl,and Cav-1 plays a critical role in this process.

[In vitro study of the secondary mesiobuccal canal of the maxillary second molar].

OBJECTIVE: To get some anatomical knowledge about the second mesiobuccal canal (MB2) of the maxillary second molar of Shandong region by studying the teeth in vitro. The anatomical knowledge may help us to improve the successful rate of root canal therapy of the maxillary molar. METHODS: 118 maxillary second molars were collected from the different region in Shandong province. Oblique square of pulp opening form was used, then root canals were detected and got through by C-type file. The rate of MB2 detection and getting through was recorded. By taken X-ray, the numbers, the morphologies and classifications of the root canal systems of these molars were recorded. Then the distance between mesiobuccal canal (MB) and MB2 was observed and measured by endodontic operating microscope and digital measurement. At last, we observed the apical foramen from the surfaces of these teeth, and try to analysis the differences between apical foramen and the end points of the roots. RESULTS: The rate of MB2 detection was 49.15%, among them 82.76% could be got through by files. 108 molars had three roots, among them, for the mesiobuccal root canal system, 46.30% were I root canal system, while II and III systems were 12.96% and 31.48%, respectively. The distance between MB and MB2 was 1.26 mm averaged. The distance between anatomical apical holes and the end points of roots was 1.13 mm averaged. CONCLUSION: MB2 can be detected in most of maxillary second molars in Shandong region. The dentists should try to detect MB2 in the root canal therapy, and should judge work length by clinical behavior and apical locator rather than by X-ray alone.