Modification of electrocyte membrane lipid composition induced by denervation

1. We determined the effect of denervation on the lipid composition of the main electric organ and electrocyte postsynaptic membrane vesicles of Electrophorus electricus. 2. Lipid extracts of whole electric organ contain mainly cholesterol, triglycerides, phosphatidylcholine and phosphatidlethanolamine. After 30 days of denervation, the lipid composition of whole electric organ did not change appreciably. 3. Lipid extracts of the membrane vesicles were similar, except that they contained mainly free fatty acids rather than triglycerides. After 30 days of denervation, cholesterol concentration was increased and phsopholipids were decreased in the membrane fraction, with higher relative concentrations of phosphatidylethanolamine and cerebrosides. 4. These results suggest that electrocyte membrane fluidity and permeability will change after 30 days of denervation

Histochemical detection of creatine kinase ion the electrocyte of Electrophorus electricus (L.)

Detection of creatine kinase, which catalyzes the conversion of ADP and phosphocreatine to ATP and creatine, was performed an the electrocyte of Electrophorus electricus (L.) using a histoenzymological method based on the formation of blue colored formazan. The results indicate that the enzyme is mainly located within the cytoplasm of the electrolyte

Lactate dehydrogenase from cultured Aedes albopictus cells: kinetic and isozyme analysis

L (+) lactate dehydrogenase (LDH) activity from cultured cells of Aedes albopictus was studies as a kinetic model of carbohydrate metabolism. Enzyme kinetics were studied in the forward (lactate as substrte) and reverse (pyruvate as substrate) reactions and the apparent Km values were obtained showing LDH higher affinity for pyruvate. The Hill coefficient values for each substrate were similar and indicate the existence of only one binding site on the enzyme. Isozyme analysis on cellulose-acetate electrophoresis presented a singe band of LDH which preumably is of the LDH-5 type. The results obtained contribute to the assumption that Aedes albopictus cells have a predominance of anaerobic metabolism