Evolution of the glycogen content and of glucose-6-phosphatase activity in the liver of Salmo gairdneri during development.

The evolution of the liver's glycogenic content, cytochemical characterization of the glycogen and glucose-6-phosphatase activity enable us to define three successive phases up to stage 36, just before the first feed. The grade which was low up to stage 24 is then due to beta-particles of ovule origin. Then, up to stage 27, there is a storage phase: alpha-particles appear and accumulate while the enzymatic activity remains non-existent. From the stage 28 to 36 the grade is progressively increasing, the enzymatic activity appears and increases. When the phase ends the liver is able to ensure glycemic regulation and to deal with exogenous nutritional contributions.