Acid phosphatase activity in mature secretory granules of the salivary gland of Bradysia hygida

✍ Scribed by E. M. Laicine; M. A. Fernandez; H. Sauaia

• Publisher: John Wiley and Sons
• Year: 1991
• Tongue: English
• Weight: 704 KB
• Volume: 208
• Category: Article
• ISSN: 0362-2525
• DOI: 10.1002/jmor.1052080302

✦ Synopsis

It is uncommon to find acid phosphatase activity in mature secretory granules. This paper demonstrates by light and electron microscope cytochemistry an acid phosphatase in mature secretory granules in the cells of one region of the salivary gland of Bradysia hygida (Diptera, Sciaridae). These secretory granules increase in number during larval development up to the beginning of the pre-pupal period when they undergo massive exocytosis. Biochemical assays show that upon exocytosis of the majority of the granules the total acid phosphatase activity in the granular gland region drops to 10% of the maximum reached before exocytosis. During and after exocytosis, two other acid phosphatases, eletrophoretically different and much weaker in activity, become increasingly detectable in all gland regions. At the same time, in whole mount preparations, numerous tiny acid phosphatase-positive granules (probably secondary lysosomes) become evident in all major cell types of the salivary gland. These results indicate that the S2 region of the salivary gland has mature secretory granules containing an acid phosphatase destined for exocytosis which is different in molecular properties from other acid phosphatases (likely lysosomal) made by the gland.