Effects of tensile stress on the alpha1 nicotinic acetylcholine receptor expression in maxillofacial skeletal myocytes.

This study was to investigate the alterations of the alpha1 nicotinic acetylcholine receptor (nAChR) levels under tensile stress stimulation in maxillofacial skeletal myocytes. The skeletal muscle satellite cells from two to three days post-natal BALB/C mice's maxillofacial muscle were collected for primary cell culture. The second passage cells in the loaded groups were subjected to cyclic tensile stress (0.5 Hz, 2000 micro strain) produced by a four point bending system for 2, 4, 6, 8, or 12 h. In the control groups, cells were cultured on similar plates and kept in the same incubator without mechanical stress loading. The examination of nAChR alpha1 receptor expression was performed by receptor binding of [125I] a-bungarotoxin. The nAChR alpha1 mRNA transcript level was analyzed by semi-quantitative RT-PCR. The result showed that the nAChR alpha1 receptor expression was elevated significantly in stress-stimulated group (P < 0.05). An increase of nAChR alpha1 in mRNA transcript level was also observed in stress groups as compared with controls (P < 0.05). It is concluded that nAChR was a possible molecular mechanism which might play an important role in mechanotransduction of tensile stress loading on maxillofacial skeletal myocytes.