An ultrastructural study of the effect of streptozotocin on the secretory ameloblasts of the rat incisor.
The acute effect of a single injection of streptozotocin (75 mg/kg) on the secretory ameloblasts of rat incisor was found to be reversible after 4 h. This effect was manifested ultrastructurally by an accumulation of secretion granules within the Golgi apparatus and a diminished accumulation of secretion granules within Tomes' process, thus suggesting a temporary inhibition of secretion. The long term effect of streptozotocin was characterized mainly by large accumulations of secretion granules within the Golgi apparatus, the presence of many lysosomal structures, an abnormal redistribution of secretion granules, and the presence of large amounts of electron-dense material within the intercellular spaces. Because the electron-dense material resembled the enamel matrix, this, and the above changes, suggested that there was a pronounced inhibition in the movement of secretion granules into Tomes' process, as well as an ectopic secretion of the enamel matrix protein.
D000565:Ameloblasts / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D000818:Animals; D003921:Diabetes Mellitus, Experimental / Q000503:physiopathology; D007180:Incisor / Q000187:drug effects* / Q000648:ultrastructure; D008854:Microscopy, Electron; D051381:Rats; D013311:Streptozocin / Q000494:pharmacology*
D013311:Streptozocin