抄録
Calponin (CALP) is a 34kDa protein which interacts with actin, tropomyosin and calmodulin, and regulates contractive roles of smooth muscle cells. The present study deals with the expression of CALP and actin in myoepithelial cells (MECs) during postnatal development of rat salivary glands. In the postnatal development of MECs, the specimens obtained from submandibular (SMG) or sublingual glands (SLG) on 0 to 84days old rats were examined by immunocytochemistry.MECs detected by CALP and actin were observed from day 0 to mature salivary glands, and the expressions of actin immunoreaction in MECs of salivary glands on days 5 or 7 were higher than those of CALP, while in MECs of salivary glands of rats over 5 weeks old, the expressions of CALP were a little higher than in actin. MECs in SMGs and SLGs during the postnatal development were characterized by existence of CALP immunoreactivity, whereas actin immunostaining was strongly localized in the smooth muscle cells of the blood vessels. No MECs detected with CALP and actin were observed in ductal segments including striated ducts and granular convoluted tubules (GCT), suggesting that the secretion from GCT cells was not related to CALP and actin. The CALP immunoreactivity is a useful marker for MECs in salivary glands in the rat.
