Hemocyte differentiation in the shore crab (Carcinus maenas) could be accompanied by a loss of glycogenosynthesis capability

Hemocytes of the shore crab C. maenas were tested for their capability to store glucose, by measurements of the glucose phosphorylating activity. The properties of this hexokinase did not reflect any hepatic role of blood cells for carbohydrate storage, since this kinase seemed not to act as a glucose sensor. Moreover, these cells did not release their glycogen in vitro, even in the presence of CHH (crustacean hyperglycemic hormone). These observations led us to reject the hypothesis considering crustacean blood cells as “circulating hepatocytes.” A study on separated hemocyte populations for their glycogen content and their ability to synthesize the polysaccharide in vitro provided preliminary results arguing for the connection of the three types of blood cells in a unique cell line. © 1993 wiley‐Liss, Inc.