Cytoplasmic granules known to contain cationic arginine-rich proteins can be identified by the ammoniacal silver reaction (ASR) which provides a cytochemical marker detectable under the electron microscope. Only the large rod-shaped granules of the chicken polymorphonuclear leukocytes (heterophils) and the large spherical azurophilic granules of the rabbit neutrophilic polymorphonuclear leukocy...

It was shown experimentally that ACTH causes an increase of cytoplasmic RNA and subcellular granules of the adrenal cortex shortly after administration. This effect was found to be concentrated primarily on the basophilic cytoplasmic granules and to be largely independent of cell division. The increase of nuclear RNA, DNA, and nuclear mass followed that of the cytoplasm. The observations indica...

We examined subcellular histamine localizations in purified human basophils that were stimulated to degranulate with FMLP using an ultrastructural enzyme-affinity technique. Basophils were collected at early (0, 20 seconds, 1 minute) and late (10 minutes to 6 hours) time points poststimulation and were prepared for routine ultrastructural and diamine oxidase-gold (DAO-gold) cytochemical analysi...

All known proteins that accumulate in the vacuolar space surrounding the obligate intracellular protozoan parasite Toxoplasma gondii are derived from parasite dense granules. To determine if constitutive secretory vesicles could also mediate delivery to the vacuolar space, T. gondii was stably transfected with soluble Escherichia coli alkaline phosphatase and E. coli beta-lactamase. Surprisingl...

The cytoplasm of the eukaryotic cell is subdivided into distinct functional domains by the presence of a variety of membrane-bound organelles. The remaining aqueous space may be further partitioned by the regulated assembly of discrete ribonucleoprotein (RNP) complexes that contain particular proteins and messenger RNAs. These RNP granules are conserved structures whose importance is highlighte...

We used a morphometric and autoradiographic approach to analyze changes in specific cytoplasmic granules and cytoplasmic lipid bodies associated with human lung mast cell degranulation. Mast cells were dissociated from lung tissue by enzymatic digestion and were then enriched to purities of up to 99% by countercurrent centrifugation elutriation and recovery from columns containing specific anti...