Larvae of the midge, Chironomus riparius possess two distinct mechanisms for ionoregulation in response to ion-poor conditions.

06:00 EDT 16th July 2010 | BioPortfolio

Summary of "Larvae of the midge, Chironomus riparius possess two distinct mechanisms for ionoregulation in response to ion-poor conditions."

This study examined the role of the anal papillae of the freshwater (FW) chironomid larva, Chironomus riparius, in ionoregulation under ion-poor conditions. The Scanning Ion-selective Electrode Technique (SIET) was utilized to characterize the species, direction and rates of inorganic ion transport by the anal papillae following acute and long-term exposure to ion-poor water (IPW). The major inorganic ions in the hemolymph of larvae treated as above were measured using standard ion-selective microelectrodes. The anal papillae of C. riparius are sites of net NaCl uptake and H+ secretion under FW and IPW conditions and are not likely to be a major contributor of K(+) exchange. Acute and long-term exposure to IPW increased total net transport of Na(+), Cl(-) and H(+) by the anal papillae but, the mechanisms underlying the increase under the two conditions were different. Acute IPW exposure increased the magnitude of net ion fluxes at sites along the anal papillae while long-term IPW exposure resulted in increased size of the anal papillae with no change in the magnitude of net ion fluxes. The contribution of the anal papillae to observed alterations of hemolymph ion activities upon exposure to IPW is discussed. Inhibitors of the Na(+)/H(+) exchangers (EIPA) and carbonic anhydrase (methazolamide) provide evidence for Na(+)/H(+) and Cl(-)/HCO(3)(-) exchange mechanisms in the anal papillae. This study demonstrates that Chironomus riparius larvae employ two different mechanisms to upregulate the total net transport of ions by the anal papillae and these mechanisms are at least partially responsible for regulating hemolymph ion activity.


1York University.

Journal Details

This article was published in the following journal.

Name: American journal of physiology. Regulatory, integrative and comparative physiology
ISSN: 1522-1490


DeepDyve research library

PubMed Articles [8789 Associated PubMed Articles listed on BioPortfolio]

Responses of the aquatic midge Chironomus riparius to DEET exposure.

N,N-diethyl-3-methylbenzamide (DEET) is the active ingredient of many commercial insect repellents. Despite being detected worldwide in effluents, surface water and groundwater, there is still limited...

Fullerenes(nC60) affect the growth and development of the sediment-dwelling invertebrate Chironomus riparius larvae.

The possible toxicity of nanoparticles (NPs) to aquatic organisms needs to be investigated for chronic effects at low concentrations. Chronic effects of carbon NPs, fullerenesC60, on the midges of Chi...

Mercury tissue residue approach in Chironomus riparius: Involvement of toxicokinetics and comparison of subcellular fractionation methods.

Along with the growing body of evidence that total internal concentration is not a good indicator of toxicity, the Critical Body Residue (CBR) approach recently evolved into the Tissue Residue Approac...

Chironomus riparius exposure to fullerene-contaminated sediment results in oxidative stress and may impact life cycle parameters.

A key component of understanding the potential environmental risks of fullerenes (C60) is their potential effects on benthic invertebrates. Using the sediment dwelling invertebrate Chironomus riparius...

Sediment properties influencing the bioavailability of uranium to Chironomus dilutus larvae in spiked field sediments.

The partitioning of metals between dissolved and solid phases directly affects metal bioavailability to benthic invertebrates and is influenced by metal-binding properties of sediment phases. Little r...

Clinical Trials [914 Associated Clinical Trials listed on BioPortfolio]

Resveratrol for Patients With Colon Cancer

Resveratrol is purported to possess cancer preventive activity, especially for colon cancer, though its mechanisms of action are not well defined. Resveratrol is found in the skin of grape...

Randomised Controlled Clinical Trials of the Effect of Therapeutic Hookworm Infection in Allergic Rhinoconjunctivitis

There has been considerable debate over the last 30 years about the interaction between asthma and parasitic infection. It has been suggested that at least part of the reason for the incre...

Erlotinib in Combination With Temozolomide in Treating Relapsed/Recurrent/Refractory Pediatric Solid Tumors

This study proposes to treat patients with the combination of erlotinib and temozolomide. Patients with relapsed, recurrent, refractory, or high risk malignancies whose tumors possess a no...

Treating Relapsed/Recurrent/Refractory Pediatric Solid Tumors With Sorafenib in Combination With Irinotecan

This study proposes to treat patients with the combination of sorafenib and irinotecan. Patients with relapsed, recurrent, refractory, or high risk malignancies whose tumors possess a non-...

Mechanisms of Human Plasticity in the Human System

The purpose of this study is to investigate the physiology associated with plasticity of the motor system. Plasticity refers to the process by which neighboring brain cells assume the res...

Medical and Biotech [MESH] Definitions

Infestation with nematode worms of the genus TRICHOSTRONGYLUS. Man and animals become infected by swallowing larvae, usually with contaminated food or drink, although the larvae may penetrate human skin.

A family of nonbiting midges, in the order DIPTERA. Salivary glands of the genus Chironomus are used in studies of cellular genetics and biochemistry.

A species of parasitic nematode found in the intestine of dogs. Lesions in the brain, liver, eye, kidney, and lung are caused by migrating larvae. In humans, these larvae do not follow normal patterns and may produce visceral larva migrans (LARVA MIGRANS, VISCERAL).

A class of drugs producing both physiological and psychological effects through a variety of mechanisms. They can be divided into "specific" agents, e.g., affecting an identifiable molecular mechanism unique to target cells bearing receptors for that agent, and "nonspecific" agents, those producing effects on different target cells and acting by diverse molecular mechanisms. Those with nonspecific mechanisms are generally further classed according to whether they produce behavioral depression or stimulation. Those with specific mechanisms are classed by locus of action or specific therapeutic use. (From Gilman AG, et al., Goodman and Gilman's The Pharmacological Basis of Therapeutics, 8th ed, p252)

A state of intersex or sexual ambiguity, involving the GENOTYPE, the GONADS, the reproductive tract, and/or the external GENITALIA or PHENOTYPE. This concept covers TRUE HERMAPHRODITISM and PSEUDOHERMAPHRODITISM. True hermaphrodites are rare and they possess gonadal tissues of both sexes, tissues from the OVARY and the TESTIS. Pseudohermaphrodites possess gonadal tissue of one sex but exhibit external phenotype of the opposite sex.

Quick Search

DeepDyve research library

Searches Linking to this Article