In the Pacific oyster, Crassostrea gigas, the energy necessary for general metabolism and gametogenesis is mainly provided by the glycogen stored in the vesicular cells. The first level of glycogen metabolism control is the entrance of glucose into cells. The monitoring of the uptake capacity of [U-14C] D-glucose revealed the existence of a saturable component with kinetic constants: Km = 0.71 mM ; Vmax = 0.22 nmol/h/106cells. The use of inhibitors has revealed the presence of carriers belonged to GLuT and SGLT types. A follow-up showed a seasonal variation of the uptake capacity and incorporation of glucose into glycogen, and a high expression of SGLT during mobilization of glycogen and gametes maturation. A bioassay in a controlled rearing system has... |