[Electron- and light microscopic study of changes in the structure of the posterior hypophyseal lobe caused by...

In 24 dogs light and electron microscopic changes of the neurohypohysis have been studied at early and intermediate periods of the prolonged compressing syndrom. The amount of neurosecrete has been stated to decrease considerably. Increased excretion of neurosecretory material from neurovascular zones is accompanied by mitochondrial swelling. Together with increased permeability of capillaries, disturbances in blood clotting system are demonstrated. With prolonged time of observations (intermediate period), further decrease of neurosecrete in axons and accumulating bodies is taking place. Some necrotic changes occur in endothelium.