Separation of immature granules containing color dye from the rat parotid gland

Parotid acinar cell contains many secretory granules. Most of granules are mature, but only little immature granules are included. These immature granules are not enough for investigation of granule maturation. In this study, we show an easy method of separation of immature granules from the rat parotid gland. In addition, we succeeded in detection of color dye in the granules. These results suggest that secretory granules can be visualized through endocytosis

The thiol-oxidizing agent diamide reduces isoproterenolstimulated amylase release in rat parotid acinar cells

In parotid acinar cells, activation of β-adrenergic receptors provokes exocytotic amylase release via the accumulation of intracellular cAMP. Cellular redox status plays a pivotal role in the regulation of various cellular functions. Cellular redox imbalance caused by the oxidation of cellular antioxidants, as a result of oxidative stress, induces significant biological damages. In this study, we examined effect of diamide, a thioloxidizing reagent, on amylase release in rat parotid acinar cells. In the presence of diamide, isoproterenol (IPR)-induced cAMP formation and amylase release were partially reduced. Diamide had no effect on amylase release induced by forskolin and mastoparan, an adenylate cyclase activator and heterotrimeric GTP binding protein activator, respectively. In the cells pretreated with diamide, the binding affinity of [3H]dihydroalprenolol to β-receptors was reduced. These results suggest that oxidative stress results in reduction of binding affinity of ligand on β-receptor and consequently reduces protein secretory function in rat parotid acinar cells