Sulfide permeability in the marine invertebrate Urechis caupo

1992 ◽  
Vol 162 (1) ◽  
Author(s):  
David Julian ◽  
AlissaJ. Arp
1998 ◽  
Vol 201 (9) ◽  
pp. 1393-1403
Author(s):  
D Julian ◽  
W E Dalia ◽  
A J Arp

Hydrogen sulfide (HS) is a well-known inhibitor of aerobic respiration via its reversible binding of mitochondrial cytochrome c oxidase, but recent studies have suggested that HS may have other non-respiratory actions. We have studied the effects of HS on spontaneous and evoked contractions in vitro under hypoxic and anoxic conditions in nerve-muscle preparations from the echiuran worm Urechis caupo. Contraction amplitude in response to electric field stimulation under anoxic conditions was completely abolished by HS within minutes in a classic dose-response relationship (Kd=31 mmol l-1, r2=0.86). Exposure of body wall and esophagus to HS in vitro for up to 6 h demonstrated that the contraction amplitude and frequency of spontaneous activity were relatively insensitive to anoxia, but that the sensitivity to HS was similar to that seen in field-stimulated muscle (Kd=2.7-32 mmol l-1). The toxic effects of HS were reversible, with almost complete recovery under anoxic conditions within the first hour. These data indicate that HS at millimolar concentrations can directly inhibit muscle contraction. Although the mechanism of this action is unknown, it does not appear to involve metabolic pathways or oxygen transport.


2015 ◽  
Vol 536 ◽  
pp. 221-227 ◽  
Author(s):  
PR Teske ◽  
J Sandoval-Castillo ◽  
M Sasaki ◽  
LB Beheregaray

The functional properties of marine invertebrate larvae represent the sum of the physiological activities of the individual, the interdependence among cells making up the whole, and the correct positioning of cells within the larval body. This chapter examines physiological aspects of nutrient acquisition, digestion, assimilation, and distribution within invertebrate larvae from an organismic and comparative perspective. Growth and development of larvae obviously require the acquisition of “food.” Yet the mechanisms where particulate or dissolved organic materials are converted into biomass and promote development of larvae differ and are variably known among groups. Differences in the physiology of the digestive system (secreted enzymes, gut transit time, and assimilation) within and among feeding larvae suggest the possibility of an underappreciated plasticity of digestive physiology. How the ingestion of seawater by and the existence of a circulatory system within larvae contribute to larval growth and development represent important topics for future research.


Biology ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 161
Author(s):  
Irene Deidda ◽  
Roberta Russo ◽  
Rosa Bonaventura ◽  
Caterina Costa ◽  
Francesca Zito ◽  
...  

Invertebrates represent about 95% of existing species, and most of them belong to aquatic ecosystems. Marine invertebrates are found at intermediate levels of the food chain and, therefore, they play a central role in the biodiversity of ecosystems. Furthermore, these organisms have a short life cycle, easy laboratory manipulation, and high sensitivity to marine pollution and, therefore, they are considered to be optimal bioindicators for assessing detrimental chemical agents that are related to the marine environment and with potential toxicity to human health, including neurotoxicity. In general, albeit simple, the nervous system of marine invertebrates is composed of neuronal and glial cells, and it exhibits biochemical and functional similarities with the vertebrate nervous system, including humans. In recent decades, new genetic and transcriptomic technologies have made the identification of many neural genes and transcription factors homologous to those in humans possible. Neuroinflammation, oxidative stress, and altered levels of neurotransmitters are some of the aspects of neurotoxic effects that can also occur in marine invertebrate organisms. The purpose of this review is to provide an overview of major marine pollutants, such as heavy metals, pesticides, and micro and nano-plastics, with a focus on their neurotoxic effects in marine invertebrate organisms. This review could be a stimulus to bio-research towards the use of invertebrate model systems other than traditional, ethically questionable, time-consuming, and highly expensive mammalian models.


2010 ◽  
Vol 394 (1-2) ◽  
pp. 63-73 ◽  
Author(s):  
Neeraj V. Gohad ◽  
Nihar M. Shah ◽  
Andrew T. Metters ◽  
Andrew S. Mount

Marine Drugs ◽  
2020 ◽  
Vol 18 (6) ◽  
pp. 298
Author(s):  
Alison E. Murray ◽  
Nicole E. Avalon ◽  
Lucas Bishop ◽  
Karen W. Davenport ◽  
Erwan Delage ◽  
...  

Polar marine ecosystems hold the potential for bioactive compound biodiscovery, based on their untapped macro- and microorganism diversity. Characterization of polar benthic marine invertebrate-associated microbiomes is limited to few studies. This study was motivated by our interest in better understanding the microbiome structure and composition of the ascidian, Synoicum adareanum, in which palmerolide A (PalA), a bioactive macrolide with specificity against melanoma, was isolated. PalA bears structural resemblance to a hybrid nonribosomal peptide-polyketide that has similarities to microbially-produced macrolides. We conducted a spatial survey to assess both PalA levels and microbiome composition in S. adareanum in a region of the Antarctic Peninsula near Anvers Island (64°46′ S, 64°03′ W). PalA was ubiquitous and abundant across a collection of 21 ascidians (3 subsamples each) sampled from seven sites across the Anvers Island Archipelago. The microbiome composition (V3–V4 16S rRNA gene sequence variants) of these 63 samples revealed a core suite of 21 bacterial amplicon sequence variants (ASVs)—20 of which were distinct from regional bacterioplankton. ASV co-occurrence analysis across all 63 samples yielded subgroups of taxa that may be interacting biologically (interacting subsystems) and, although the levels of PalA detected were not found to correlate with specific sequence variants, the core members appeared to occur in a preferred optimum and tolerance range of PalA levels. These results, together with an analysis of the biosynthetic potential of related microbiome taxa, describe a conserved, high-latitude core microbiome with unique composition and substantial promise for natural product biosynthesis that likely influences the ecology of the holobiont.


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