The Intermediary Metabolism of Nematode Parasites

Massey, Vincent; Rogers, WP

doi:10.1071/bi9500251

Cited by 6 publications

(3 citation statements)

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“…The activity shown by the hepatopancreas suspensions is about one-tenth that of similar preparations of rat liver. From a study of the data of Massey, & Rogers (1950) it would appear that the nematode tissue examined possessed an aerobic respiration of the same order as that of the hepatopancreas. These activities are low in contrast to those obtained by us for muscle preparations of LocuBta migratoria (unpublished) and for cockroach muscle (Barron & Tahmisian, 1948).…”

Section: Discussionmentioning

confidence: 99%

Aerobic metabolism of the hepatopancreas of Helix pomatia

Rees

1953

Biochemical Journal

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The presence ofthe tricarboxylic-acid cycle (Krebs's cycle) has been demonstrated in most mammalian tissues investigated (Krebs & Johnson, 1937; Green, Loomis & Auerbach, 1948), where it appears to be the major pathway for the oxidation of carbohydrate, fat and protein intermediaries. No detailed examinations have been made in the invertebrates. However, evidence has been presented of Krebs's cycle activity in certain nematodes (Massey & Rogers, 1950), the cockroach (Barron & Tahmisian, 1948) and Drosophila (Spirtes, 1951). No similar studies have been made in Helix pomatia. The evidence of Biedermann (1911), Baldwin (1938) and Vonk, Mighorst & de Groot (1950) suggests that the hepatopancreas plays an important role in the metabolism of the animal. The enzyme systems examined in the present investigation were those contained in suspensions and mitochondrial preparations from the hepatopancreas of both hibernating and active H. pomatia, since there is evidence of changes in the enzymes of an organism during hibernation (Baldwin, 1938; Suomalainen, 1935). METHODS The snails used in these experiments were either kept in the refrigerator in the hibernating state, or had been active and fed on cabbage in the laboratory at 220 for at least 7 days before use. Unless otherwise specified, results reported in this paper were obtained with preparations from active H. pomatia. Enzyme preparations Suspensions. The hepatopancreas was rapidly removed and ground in an ice-cold Potter 'homogenizer' in either 0-2M-sucrose solution or 0 5 % KCl solution. The suspension was diluted with the appropriate medium to give a final concentration of approximately 20% tissue. Mitochondria. These were isolated according to the methods described by Schneider (1948) using 10% hepatopancreas suspensions made in 0 2M-sucrose. All preparations were carried out in a cold room at 20, a Servall SS-l-a high-speed centrifuge being used for the isolation of the mitochondria. Hexokinase. This was obtained by the method of Berger, Slein, Colowick & Cori (1946) as described by Cross, Covo, Taggart & Green (1949). The preparation was stored as a frozen solution at-100 and retained its activity for many months. The conditions for autolysis for baker's yeast were those described by Bailey & Webb (1948). Determinations Inorganic orthophosphate was determined by the method of Fiske & Subbarow (1925), and x-ketoglutarate and pyruvate by the method of Friedemann & Haugen (1943). Citrate was determined by the method of Natelson, Pincus & Lugovoy (1948) and sometimes by that of Weil-Malherbe & Bone (1949). Succinate was determined by the method of Krebs (1937). 02 uptakes were determined manometrically; the gas phase was air.

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Section: Discussionmentioning

confidence: 99%

Aerobic metabolism of the hepatopancreas of Helix pomatia

Rees

1953

Biochemical Journal

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“…The nematode parasites concerned are able to oxidize pyruvate via the tricarboxylic acid cycle (Massey and Rogers 1950a). It may besaid, then, that fiuoroacetate has a similar action on the microorganisms, the vertebrate tissues, and the nematode parasites that it poisons.…”

Section: Nilmentioning

confidence: 99%

“…In these organisms aerobic energy is probably obtained from the reactions of the tricarboxylic acid cycle (Massey and Rogers 1950a). Acetate is rapidly metabolized by the parasites, condensing, either as acetate or a closely related compound, with oxaloacetate to form citrate (Massey and Rogers, unpublished data).…”

Section: Introductionmentioning

confidence: 99%

Conditions Affecting the Action of Fluoroacetate on The Metabolism of Nematode Parasites and Vertebrate Animals

Massey¹,

Rogers²

1951

Aust. Jnl. Of Bio. Sci.

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SummaryThe respiration of brei or mince prepared from pigeon breast muscle containing 0.0003M methylene blue was very little affected by O.OIM Huoroacetate.Under similar conditions, the respiration of preparations from Ascaridia galli and Nematodirus spp. was inhibited 3.5-50 per cent. This inhibition was lessened by adding intermediates of the tricarboxylic acid cycle. Succinate was most effective in lifting the inhibition; oxaloacetate was least effective. The formation of citrate in brei of Nematodirus, containing methylene blue and added acetate and oxaloacetate, was increased more than 100 per cent. when Huoroacetate, O.OIM, was present. The utilization of citrate in mince prepared from Nematodirus containing 0.0003M methylene blue was strongly inhibited by O.OIM Huoroacetate when a gas phase of air was used; under anaerobic conditions no inhibition was found. Similar preparations from pigeon liver and pigeon breast muscle were inhibited only to a small degree, about 20 per cent., under aerobic conditions, and not at all under anaerobic conditions. When methylene blue was not added, the inhibition of citrate utilization in pigeon breast muscle preparations in air rose to" about 50 per cent.; under oxygen the inhibition rose to 100 per cent. When cytochrome c, 5 x lo-6M, was added, the inhibition was 100 per cent., even in a gas phase of air.The inhibition of citrate utilization in mince prepared from pigeon breast muscle was examined at different oxidation-reduction potentials maintained by electrolysis. At Eh levels below +50 mV., O.OlM Huoroacetate caused inhibitions of 0-25 per cent.; at levels above + 120 m V. the inhibition ranged from 65 to 100 per cent.The possibility that it was necessary for Huoroacetate to be metabolized for a period before inhibition occurred was also examined. Mince prepared from pigeon breast muscle, to which was added 0.025M oxal~acetate and Huoroacetate, was pre-incubated for 15 min. under oxygen, or under oxygenfree nitrogen. Thereafter, the inhibition of citrate utilization occurring under air, oxygen, or nitrogen during a period of 30 min. was determined. Inhibition in air after pre-incubation in nitrogen was 20-30 per cent.; after preincubation in oxygen, 80-90 per cent. After pre-incubation in oxygen, inhibition in nitrogen was nil, and in oxygen, 100 per cent.It is suggested that these results support the hypothesis "that Huoroacetate condenses with oxaloacetate to form the actual inhibitor. Both the formation of the inhibitor and the inhibiting reaction were increased in the presence of oxygen.• Ian McMaster Scholar.

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Die Einzelnen Tierstämme der Wirbellosen

Buddenbrock

1956

Vergleichende Physiologie

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The Intermediary Metabolism of Nematode Parasites

Cited by 6 publications

References 5 publications

Aerobic metabolism of the hepatopancreas of Helix pomatia

Aerobic metabolism of the hepatopancreas of Helix pomatia

Conditions Affecting the Action of Fluoroacetate on The Metabolism of Nematode Parasites and Vertebrate Animals

Die Einzelnen Tierstämme der Wirbellosen

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