Cytochemical demonstration of amine-storing vacuoles and lysosomes in the chicken thrombocytes.

A combined electron microscopic and cytochemical study of the thrombocytes of the chicken has clearly identified the amine-storing organelles and lysosomes. A chromaffin positive-reaction product was observed on the inner surface and the granules of the large electron-lucent vacuoles. No acid phosphatase activity was localized in these amine-storing vacuoles. However, the acid phosphatase activity was observed in the small vesicles, the primary lysosomes, and in the large electron dense inclusions with myelin which may be secondary lysosomes. The results of this study suggest that the large empty vacuoles, with one or two very dense osmiophilic peripherally-situated granules, in the chicken thrombocytes are comparable to the vesicles with electron dense materials called "dense bodies" in mammalian thrombocytes.