Secretion of the Content of Granules and Its Relationship to the Acid Phosphatase Reaction in Regenerating Rat Peritoneal Mast Cells

Relationship between the staining property of mast cell granule with alcian blue-safranin O and toluidine blue O, and the content of mast cell protease I in the granule of rat peritoneal mast cell.

“…Later he reported a sequential alteration of mast cell granules from electron-optically compact granules through fine reticular granules to almost empty granular sacs in the regenerating mast cell population of rat ascitic fluid. Though this phenomenon is prominent in the regenerating ascitic mast cells, it is also found in a lesser degree in the normal untreated rats (13). These less dense granules of normal rat ascitic mast cells are prominent in young rats and decrease with age (unpublished data).…”

“…Recently, Miyashita et al showed that the alcian blue positive granules correspond to the reticular granules with positive acid phosphatase reaction and the safranin positive granules correspond to the compact granules with negative acid phosphatase reaction (7). With these results the secretion of granular content suggested by Takeoka (12,13) can be related to the secretion of RMCP I.…”

“…Among the proteins, the rat mast cell protease I (RMCP I) is the largest in amount (10). It is suspected that the ultrastructural alteration reported by Takeoka (12,13) in the granule content would be largely related to the change of amount of RMCP I in the granules.…”

“…In the regenerating mast cells the sequential ultrastructural alterations are intimately related with acid phosphatase reaction of the granules (13). The acid phosphatase reaction is not found in the compact granules, intensive in the reticular granules and less prominent with the decrease of electron density of granules.…”

Acid phosphatase reaction and Alcian Blue-Safranin staining of rat peritoneal mast cells.

“…the Acp positive granules correspond to the Alcian Blue positive granules and the Acp negative granules to the Safranin positive granules. Takeoka (4) assumed that the morphological variation of granules from the compact and dense ones to the reticular and less dense ones was a morphological reflection of degradation of granular content prior to the secretion of biologically active substances. He also speculated that the Acp reaction in the granules showed the presence of lysosomal enzymes in the granules and that the lysosomal enzymes played important roles in the degradation of contents of granules.…”