Studies on the metabolism of Echinococcus granulosus. I. General chemical composition and respiratory reactions

Abstract

1. 1. Hydatid cyst scolices contain large amounts of protein and smaller amounts of lipids. Less inorganic substances are present than in other immature tapeworms. Two polysaccharides are stored: glycogen and a polysaccharide containing galactose and glucosamine. 2. 2. Under an oxygen tension of atmospheric air the scolices consume oxygen at a rapid rate (Qo2 = 2) with an over-all RQ of 0.88. 3. 3. The anaerobic CO2 production is pronounced, but the sources of this CO2 have not been established. 4. 4. The aerobic and anaerobic gaseous exchanges are highly sensitive to inhibitors of glycolysis, but dl-glyceraldehyde is completely ineffective. 5. 5. The aerobic respiration is markedly cyanide sensitive. 6. 6. The aerobic respiration is inhibited by fluoroacetate, but not by malonate. 7. 7. The Q10 of the oxygen consumption is 2.1 in the range 28 to 38 °C. Temperatures of 42 and 45 °C are beyond the optimum. 8. 8. The respiration remains about constant in the pH range 4.5 to 8.5. 9. 9. Th