Response of blood cells to hemorrahagic shock in the dog.

Response of canine blood cells to hemorrhagic shock was examined using ultrastructural and ultracytochemical techniques. Blood platelets responded to hemorrhagic shock with a decrease of alpha-granules and the simultaneous development of the platelet canalicular system which opened to the extracellular environment, and platelets having no or few granules appeared at the end of the experimental period. Neutrophil leukocytes also responded to shock, with the decrease of both specific and azurophil granules. Eosinophil leukocytes were morphologically unchanged before and after shock but basophils were not found in the present observations. The effects of dexamethasone and phenoxybenzamine on inhibition of blood cell degeneration during hemorrhagic shock were examined. These drugs were considerably effective to inhibit degeneration of blood cells.