Palla S. Reddy

Cadmium chloride induced hyperglycemia in the red swamp crayfish, Procambarus clarkii: Possible role of crustacean hyperglycemic hormone

Exposure to 5 ppm cadmium chloride for up to 72-hr produces hyperglycemia in intact Procambarus clarkii, but not in eyestalkless individuals. Extracts of eyestalks, regardless of whether the eyestalks are from cadmium exposed crayfish or crayfish kept in clean water, produce a greater hyperglycemia in eyestalkless crayfish kept in clean water than in cadmium exposed eyestalkless crayfish. This difference in effectiveness of the extracts may represent a decreased responsiveness of cadmium exposed crayfish to the crustacean hyperglycemic hormone. These results support the hypothesis that cadmium induced hyperglycemia is mediated at least in part by the crustacean hyperglycemic hormone that is produced in the eyestalk.

Effect of cadmium chloride on amylase activity in the red swamp crayfish, Procambarus clarkii

Abstract Exposure of intact Procambarus clarkii to cadmium chloride results in both an increase of the pH and a decrease in the amylase activity in the digestive juice. The pH optimum for amylase activity is 5.8 in both the digestive juice and hepatopancreas. The results are discussed in terms of the toxicity of cadmium to the secretory cells in the hepatopancreas.

Effect of cadmium exposure on lactate dehydrogenase activity in the hepatopancreas and abdominal muscle of the fiddler crab, Uca pugilator

Abstract 1. Lactate dehydrogenase (LDH) activity in the hepatopancreas and abdominal muscle of fiddler crabs, Uca pugilator, was determined after 24 and 48 hr of exposure to 2 ppm cadmium chloride. 2. For the cadmium exposed crabs, LDH activity in the hepatopancreas decreased, whereas that in the abdominal muscle increased. 3. The increased LDH activity in the abdominal muscle may reflect increased dependence on anaerobic carbohydrate metabolism in fiddler crabs exposed to cadmium in their environment.