Secretory stages of individual CHH-producing cells in the eyestalk of the crayfish Astacus leptodactylus,determined by means of immunocytochemistry

Summary Immunocytochemical staining demonstrates striking differences in staining intensity among individual crustacean hyperglycemic hormone (CHH)-producing cells in the eyestalk of the crayfish Astacus leptodactylus. Based on these differences we arbitrarily subdivided the CHH-cells into three categories representing increasing immunoreactivity respectively: + cells, + + cells, and + + + cells. Electron microscopic investigations reveal that these differences in immunostaining are correlated with differences in the numerical density of the neurosecretory granules in the cytoplasm and that these may reflect differences in activity among the CHH-cells. Morphometric analyses at the light- and electron-microscopic levels indicate that the three distinguished categories of immunopositive cells represent different stages in the CHH-synthesizing process of the cells. The results of the present study demonstrate the application of the PAP-technique at the light-microscopic level as a method to obtain information pertaining to the dynamics of secretory activity of the CHH-cells.