The ultrastructure of the Herring bodies in rats subjected to different experimental conditions.

A study of the morphology of Herring bodies of the posterior pituitary lobe of rats treated with colchicine and/or exposed to low temperatures has been performed. After treatment with colchicine (20 microgram in distilled water injected intracisternally) a predominance of Herring bodies with a large number of small "synaptic-like" vesicles surrounded by neurosecretory granules is found. Exposures to low temperature (4-6 degrees C) result in an increase in the neurosecretory material and the Herring bodies show many neurosecretory granules of different densities. After treatment with colchicine and subsequent exposure to low temperatures, the Herring bodies are characterized by having a great number of autophagic bodies which become more numerous as the length of the exposure is increased; later autophagic vacuoles and lamellar bodies become evident.