Fig. 5

Photomicrographs of H&E-stained sections. A The GMSCs-treated parotid gland tissue section with restored normal structural architecture; the interlobular connective tissue is thin with some adipocytes (↑↑) and interlobular excretory ducts (*); each lobule is formed of nearly normal tightly packed serous acini (arrowheads) and numerous striated ducts (↑). (H&E ×100). B A higher magnification GMSCs-treated parotid gland tissue section showing closely packed serous acini with restoration of their basal basophilia and apical acidophilic granules (arrowheads); the intercalated ducts can be seen with narrow lumen and lined by simple squamous epithelium (*); the striated ducts have large lumina and lined by simple columnar cells that exhibit basal acidophilic striations (↑). (H&E X400). C The radiated parotid tissue section shows a remarkable increase in interlobular space with an apparent increase in adipocytes (*), denoting significant parenchymal atrophy with widely atrophied serous acini (arrowheads) and noticeable inter-acinar spaces (↑↑); the striated ducts exhibit noticeable dilatation (↑). (H&E ×100). D Higher magnification of the radiated parotid gland tissue section shows completely disorganized and atrophied serous acini with pyknotic nuclei (arrowheads) and noticeable inter-acinar spaces (↑↑); the striated duct exhibits vacuolated cytoplasm with pyknotic nuclei (↑) and dilated lumen (*). (H&E ×400). E The section of normal parotid tissue (control) showing normal structural architecture, surrounded by a capsule (C) arises from its loose interlobular connective tissue with some adipocytes (↑↑) and interlobular excretory ducts (*); each lobule is formed of tightly packed serous acini (arrowheads) and numerous striated ducts (↑). (H&E ×100). F A higher magnification of normal parotid tissue section (control) shows closely packed serous acini with basal basophilia and apical acidophilic granules (arrowheads), the striated ducts have large lumina and are lined by simple columnar cells with basal acidophilic striations (↑). (H&E ×400)