Evidence for the involvement of the crustacean hyperglycemic hormone in the regulation of lipid metabolism.

Effects of the crustacean hyperglycemic hormone on total lipids in the hemolymph of Chasmagnathus granulata and on free fatty acids, phospholipids, and triglycerides in the hemolymph of Carcinus maenas, as well as on their release by Orconectes limosus hepatopancreas in vitro, were investigated. Eyestalk ablation led to a significant decrease of total lipids in the hemolymph of C. granulata and of free fatty acid levels in C. maenas. Crustacean hyperglycemic hormone injections completely reversed the effects of eyestalk extirpation in short-term experiments. Crustacean hyperglycemic hormone also caused significant elevations of hemolymph phospholipids and triglycerides in eyestalkless C. maenas. The release of free fatty acids and phospholipids from O. limosus hepatopancreas in vitro was significantly increased in the presence of crustacean hyperglycemic hormone. These results suggest a physiological role for crustacean hyperglycemic hormone in the control of lipid metabolism in crustaceans. This role may be similar to that of the adipokinetic hormone of insects.