Excretory/secretory products of Haemonchus contortus inhibit aminopyrine accumulation by rabbit gastric glands in vitro

Merkelbach, P; Scott, Ian; Khalaf, S; Simpson, H.V.

doi:10.1016/s0304-4017(01)00635-5

Cited by 16 publications

(15 citation statements)

References 36 publications

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“…H. contortus excretory/secretory products (ES), which are released by GINs to their environment, consist of diverse bioactive components, including chemotaxins, metabolic end-products, enzymes, immunomodulators and growth factors. ES has been reported to inhibit acid secretion in vitro [191], as well as restrain the enterochromaffin-like cells, which may indirectly cause diminished acid secretion by parietal cells [187; 192]. Ovine gastrointestinal nematode chemotaxins recruit granulocytes in vitro [193], which could be another way of damaging parietal cells in vivo [163; 167].…”

mentioning

confidence: 99%

Haemonchus Contortus and Ovine Host: A Retrospective Review.

Ashram¹,

Nasr²,

Mehmood³

et al. 2017

IJAR

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Gastrointestinal (GI) parasitic infections are a world-wide problem for both small-and large-scale farmers. Infection by GI parasites in ruminants, including sheep and goat can result in harsh economic losses in a variety of ways: reproductive inefficiency, decreased work capacity, involuntary culling, diminished food intake, poor animal growth rates and lower weight gains, treatment and management costs, and mortality in heavily parasitized animals. Among the GI parasites that cause losses to the farming industry, the barber"s pole worm Haemonchus contortus is the predominant, blood-sucking, highly pathogenic, and economically important nematode that infects small ruminants. Here, we review the historical and recent literature on the ovine-parasite-environment interaction for H. contortus to bring avenues where advances in the understanding of these interactions is an indispensible to develop a cost effective control strategies as potential options for the haemonchosis control in sheep and the proper management of sheep in various production systems.

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mentioning

confidence: 99%

Haemonchus Contortus and Ovine Host: A Retrospective Review.

Ashram¹,

Nasr²,

Mehmood³

et al. 2017

IJAR

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“…Ammonia, a principal nitrogenous excretory product of parasites (Barrett 1981), is cytotoxic and inhibits acid secretion in dispersed rabbit gastric glands (Fryklund et al 1990;Hagen et al 1997;Merkelbach et al 2002) and in amphibian gastric mucosa (Hagen et al 2000). The weak base also reduces proliferation of cells in culture (Hassell et al 1991;Schneider et al 1996) and induces cell damage (Barer et al 1988;Smoot et al 1990) and cell vacuolation (De Duve et al 1974;Ohkuma and Poole 1981;Xu et al 1990;Cover et al 1991).…”

Section: Discussionmentioning

confidence: 93%

“…Emergence and lifecycle progression to L4 coincides with the inhibition of gastric acid secretion but direct transfer of adult nematodes into the abomasum of sheep can mimic both the rapid rise in abomasal pH and the equally rapid recovery when parasites are removed by anthelmintic treatment (Simpson et al 1997). This, together with the observation that ES products from adult H. contortus inhibit aminopyrine accumulation by isolated rabbit gastric glands (Merkelbach et al 2002), suggests that excreted or secreted products of the parasites may interfere directly with parietal cell function (Anderson et al 1985;Simpson et al 1997;Scott et al 2000) and also that this activity might be common to ES products derived from different lifecycle stages. The mechanisms responsible remain uncertain but seem to be a crucial step for host pathology as well as worm survival (Haag 1995;Stringfellow 1986).…”

Section: Introductionmentioning

confidence: 80%

Effects of excretory/secretory products of Haemonchus contortus on cell vacuolation

et al. 2005

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Excretory/secretory (ES) products of the gastric nematode, Haemonchus contortus, have been implicated in the inhibition of gastric acid secretion which follows infection. Parietal cell vacuolation has been observed in abomasal sections from parasitised sheep, and ES prepared in vitro has been reported to cause vacuolation and to increase neutral red (NR) uptake in epithelial cell cultures. We have used the latter approach to examine, at the cellular level, the effects of ES prepared from L3 and adult nematodes. Both NR uptake and cellular vacuolation were increased following exposure to larval or adult ES products. ES preparations from adult worms induced more extensive vacuolation then those from L3 worms and, as with VacA treatment, adherent cells remained viable despite high levels of vacuolation. Whereas VacA-induced vacuolation resulted in NR uptake predominantly localised in vacuoles, this appeared not to be the case with ES-induced vacuolation, suggesting that different mechanisms might be involved. Both ES and VacA exposure was associated with an increased rate of cell detachment.

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“…The lack of effect in vitro of ES products of both H. contortus and O. circumcincta (Lawton et al 2002) on gastrin secretion as well as on pepsinogen secretion (unless the fundic tissue is obtained from sheep previously exposed to parasites) (Scott and McKellar 1998) suggests that parasite survival may depend more on acid inhibition than on hypergastrinaemia and pepsinogenaemia in the host. We have shown that H. contortus ES products inhibit aminopyrine accumulation by gastric glands (a measure of acid secretion) (Merkelbach et al 2002), therefore, understanding how abomasal parasites inhibit and kill parietal cells may reveal a key component of the host-parasite interaction which may be amenable to blocking as a novel anthelmintic strategy.…”

Section: Discussionmentioning

confidence: 98%

The failure of Haemonchus contortus excretory/secretory products to stimulate gastrin secretion in vitro

2004

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Excretory/secretory (ES) products collected from exsheathed L3 or parasitic stages of Haemonchus contortus were tested in vitro for gastrin stimulatory properties using an ovine abomasal antral mucosal preparation. In addition, the motility of exsheathed L3 and parasites recovered on weeks 2, 6 and 8 post-infection was studied in water, saline, saline with glucose or ovine blood and in HBSS pH 2.5-7.4. Parasitic stages became immotile rapidly in water and HBSS pH 2.5, more slowly in HBSS pH 3.5, but nearly 100% remained motile for 48 h when blood was included in the medium. Exsheathed L3 motility was reduced only by water and HBSS pH 2.5, and then only in the second week of incubation. Gastrin secretion was not consistently increased by any of the parasite ES products tested in vitro, therefore, they probably do not stimulate the G cell directly to produce the hypergastrinaemia seen in parasitised sheep.

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Excretory/secretory products of Haemonchus contortus inhibit aminopyrine accumulation by rabbit gastric glands in vitro

Cited by 16 publications

References 36 publications

Haemonchus Contortus and Ovine Host: A Retrospective Review.

Haemonchus Contortus and Ovine Host: A Retrospective Review.

Effects of excretory/secretory products of Haemonchus contortus on cell vacuolation

The failure of Haemonchus contortus excretory/secretory products to stimulate gastrin secretion in vitro

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