Studies on the Metabolism of the Filarial Worm, Litomosoides Carinii

Bueding, Ernest

doi:10.1084/jem.89.1.107

Cited by 126 publications

(39 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Independent of whether oxygen was present or not glucose was catabolized by the parasites to form L-lactate, acetate, acetoin and CO 2 . However, in agreement with earlier findings (Bueding, 1949), considerably more lactate (i.e. 88 % of the glucose utilized) but only slight amounts of acetate and acetoin accumulated under anaerobic as compared to aerobic conditions.…”

Section: Glucose Uptake and Carbon Balance Studiessupporting

confidence: 92%

“…The host animals were killed in chloroform vapour and the worms were subsequently removed and transferred to basic filarial medium (BFM) (Bueding, 1949).…”

Section: Parasitesmentioning

confidence: 99%

“…Unlike the majority of helminths studied so far, the adult stage of Litomosoides carinii shows an oxygen requirement for maintenance of motility, and possibly for survival (Bueding, 1949;Saz, 1981). In spite of this, the filariid was incapable of completely oxidizing substrates to carbon dioxide and water (Bueding, 1949;230 TH.…”

Section: Introductionmentioning

confidence: 99%

“…In spite of this, the filariid was incapable of completely oxidizing substrates to carbon dioxide and water (Bueding, 1949;230 TH. RAMP AND P.KOHLER Wang & Saz, 1974).…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Glucose and pyruvate catabolism inLitomosoides carinii

Ramp¹,

Kohler²

1984

Parasitology

View full text Add to dashboard Cite

SUMMARYThe filarial worm Litomosoides carinii showed a rapid uptake of glucose during in vitro incubation. This uptake proceeded linearly with time, and was significantly higher under aerobic compared to anoxic conditions. Under an atmosphere of nitrogen the worms converted glucose almost quantitatively to lactate, whereas in the presence of oxygen appreciable quantities of acetate, acetoin and CO 2 , in addition to lactate, were formed. Although aerobically only 73 % of the carbohydrate carbon could be accounted for by the latter products as well as by a net glycogen synthesis, attempts to identify other compounds presumed to be derived from glucose metabolism have been unsuccessful. The complete sequence of the glycolytic enzymes was detected in particulate-free cytosolic extracts of the filarial worm. With the exception of 6-phosphofructokinase, all glycolytic enzyme activities were considerably higher than those reported for rat liver. In addition, L. carinii possesses the entire set of enzymes catalysing the eight successive reaction steps of the tricarboxylic acid cycle. On a mitochondrial protein basis, the specific activities of these enzymes were similar to those present in rat liver. Various enzymatic activities of the mitochondrial respiratory chain were detected in the parasite. These include low levels of NADH and cytochrome c oxidases, but a high activity value for NADH dehydrogenase. Cell-free extracts and the mitochondrial fraction of the worms were found to exhibit an enzyme capable of catalysing the decarboxylation of pyruvate. Since this activity was stimulated 5-to 20-fold by the cofactors known to be required by the pyruvate dehydrogenase complex of other animal cells, pyruvate decarboxylation and thus acetate formation in the parasite may be mediated by an enzyme similar to, or identical with, the pyruvate dehydrogenase system. Isotopic carbon balance studies and experiments in which substrates specifically labelled with 14 C were employed showed that substrate carbon can to some extent enter into respiratory CO 2 . From these and the enzymatic analyses it is suggested that complete oxidation of carbon substrate may be of relevance as an energy-conserving pathway in the filarial worm.

show abstract

Section: Glucose Uptake and Carbon Balance Studiessupporting

confidence: 92%

“…The host animals were killed in chloroform vapour and the worms were subsequently removed and transferred to basic filarial medium (BFM) (Bueding, 1949).…”

Section: Parasitesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…In spite of this, the filariid was incapable of completely oxidizing substrates to carbon dioxide and water (Bueding, 1949;230 TH. RAMP AND P.KOHLER Wang & Saz, 1974).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Glucose and pyruvate catabolism inLitomosoides carinii

Ramp¹,

Kohler²

1984

Parasitology

View full text Add to dashboard Cite

show abstract

“…The length of the preparation was 4-5 cm, and the tension on the preparation was approximately 25 mg. The worm was bathed in a basic filarial medium (Bueding, 1949).…”

Section: Methodsmentioning

confidence: 99%

Actions of acetylcholine and GABA on spontaneous contractions of the filariid, Dipetalonema viteae

Christ

Goebel

Saz

1990

British J Pharmacology

View full text Add to dashboard Cite

Isotonic contractions were recorded from the filarial nematode, Dipetalonema viteae (Acanthocheilonema viteae), in an isolated tissue chamber. Nicotine (10−6 m) and pilocarpine (10−5 m) increased the spontaneous contractions in the intact filariid, but acetylcholine (ACh, 10−4 m) and muscarine (10−5 m) were inactive. When ACh was applied to an opened D. viteae, it was 10,000 times more potent. This indicates that the cuticle is an effective barrier to the penetration of ACh to the muscle cells. The effects of ACh on the opened D. viteae were not affected by hexamethonium (10−3 m) or atropine (10−5 m) and were only partially reduced by (+)‐tubocurarine (10−4 m). γ‐Aminobutyric acid (GABA, 10−3 m) reduced the spontaneous activity of the intact D. viteae; however, the effect of GABA had a slow onset and recovery. Muscimol (10−5 m) was more potent than GABA and had a more rapid onset and recovery. GABA was 1,000 times more potent on the opened D. viteae than on the intact D. viteae. Baclofen (10−3 m) was inactive on both preparations. The effect of GABA was not antagonized by bicuculline (10−4 m), picrotoxin (10−5 m) or penicillin G (10−3 m). It is concluded that the filariid cuticle acts like a lipid structure and blocks the penetration of polar substances, such as ACh and GABA. Also, due to the lack of efficacy of the ACh and GABA antagonists, it was concluded that the nematode receptors are somewhat different from the mammalian ACh and GABA receptors.

show abstract