Figure 1: (A) A photomicrograph of the submandibular gland of rat treated by 10 mg/kg methotrexate, showing areas of hemorrhage suround the straiated ducts specialy the large one (A1, H&E ×100; A2, H&E ×400). (B) Submandibular gland of rat treated by 20 mg/kg methotrexate, showing stasis of acini secretions within the ducts (B1, H&E ×100). Some times seepage of the duct secretion outside the duct causing shrinkage of its epithelium. Acinar cells swelling which contain large granules in their cytoplasm are also seen(large arrow) with enlargement of the granular convoluted tubules(small arrow) (B2, H&E ×400).(C) Submandibular gland of rat treated by 40 mg/kg methotrexate, the acini showing loss of their normal architecture(C1, H&E ×100). Cytoplasmic vacuolation of some cells (arrow) which showing different cell sizes and nuclear sizes with marked congestion of the blood capillaries The ducts become highly dilated with discontinuity of their epithelial lining in some areas (C2, H&E ×400).