Oxygen and the developing eggs and larvae of the lumpfish, Cyclopterus lumpus

1983 ◽  
Vol 63 (3) ◽  
pp. 633-640 ◽  
Author(s):  
John Davenport
Keyword(s):  
Oxygen Uptake ◽  
Sea Water ◽  
Early Stage ◽  
Clupea Harengus ◽  
Low Oxygen ◽  
Egg Masses ◽  
Cyclopterus Lumpus ◽  
Hypoxic Conditions ◽  
Slow Development ◽  
Eggs And Larvae

Unfertilized eggs in the oviducts of female lumpsuckers are exposed to low oxygen tension (ca. 40% air saturation). After spawning and fertilization water agitation aids percolation of water through Cyclopterus egg masses, but early in development oxygen tensions within non-ventilated egg masses fall slowly because of the eggs’ low metabolic rate (consistent with their slow development – 40 days to hatching at 5 °C). There is a considerable increase in oxygen uptake at hatching; in this respect the lumpsucker resembles the herring, Clupea harengus.Early stage eggs are tolerant of hypoxic conditions and can even survive brief exposure to anoxic sea water. Later eggs and larvae are much more susceptible to oxygen lack. However, fanning behaviour by the brooding male parent (usually assumed to be designed to promote oxygen uptake by egg masses) is almost continuous at the beginning of development but becomes less frequent later. It is suggested that the initial intensive fanning helps to drive off ammonia which is released as the eggs stick together.

Ammonia output by eggs and larvae of the lumpsucker, Cyclopterus lumpus, the cod, Gadus morhua and the plaice, Pleuronectes platessa

1983 ◽  
Vol 63 (3) ◽  
pp. 713-723 ◽  
Author(s):  
John Davenport ◽  
Sunniva Lønning ◽  
Elin Kjørsvik
Keyword(s):  
Slow Rate ◽  
Gadus Morhua ◽  
Sea Water ◽  
Ammonia Excretion ◽  
Low Oxygen ◽  
Ovarian Fluid ◽  
Cyclopterus Lumpus ◽  
Metabolic Output ◽  
Eggs And Larvae ◽  
Comparable Size

Cod and plaice eggs show a gradually increasing rate of ammonia excretion during development and in neither species was there a great change in individual output at hatching. The rates of ammonia excretion recorded for cod and plaice larvae were similar to those recorded for planktonic Crustacea of comparable size by Conover & Corner (1968).Lumpsucker eggs and larvae have a basically low rate of ammonia excretion (consistent with their slow rate of development and low oxygen consumption), but much ammonia was released from the eggs in the first day or two after spawning. This ammonia was of non-metabolic origin, but was not accumulated from the ovarian fluid prior to spawning. Lumpfish eggs become very sticky when they are first exposed to sea water, but this stickiness is lost within 24 h. Stickiness stems from a viscous elastic slime; it is suggested that the non-metabolic output of ammonia is caused by changes in the composition of the slime as the eggs are bound together in a lattice.

Oxygen Uptake of Developing Eggs and Larvae of the Herring (Clupea Harengus)

1964 ◽  
Vol 44 (3) ◽  
pp. 711-723 ◽  
Author(s):  
F. G. T. Holliday ◽  
J. H. S. Blaxter ◽  
Reuben Lasker
Keyword(s):  
Oxygen Uptake ◽  
Dry Weight ◽  
Clupea Harengus ◽  
Baltic Herring ◽  
Detectable Difference ◽  
Effects Of Temperature ◽  
Eggs And Larvae ◽  
Effect Of Age

SUMMARYThe oxygen uptake of eggs and larvae of Norwegian herring from Bergen (mean unfertilized egg dry weight about 035 mg) and of Baltic herring from Kiel (mean unfertilized egg dry weight about 0·10 mg) was measured by a reference diver and a Warburg respirometer. Anaesthetized Kiel larvae had values of about 0·10μl./larva/h and Bergen larvae 0·25μl./larva/h. When expressed as Qo (μl./mg dry weight/h) the values became Kiel 2·3, Bergen 2·5.Oxygen uptake of embryos before hatching and of larvae, expressed as Qo, was most affected by activity, increasing in very active organisms by five to ten times the resting value of 1-2 μl./mg dry weight/h. Experiments to test the effects of temperature and salinity were done using anaesthetized larvae in some cases.Temperature experiments with larvae gave a Q10 of about 2, the Qo, of anaesthetized Kiel larvae ranging from about 2·0 at 50° C to 35 at 14°C, and that of unanaesthetized Bergen larvae from 2·5 at 6° C to 50 at 140°C.Eggs and larvae of both races reared in salinities from 5 to 50 %0 showed no detectable difference in oxygen uptake. However, abrupt transfer of anaesthetized larvae from one salinity to another caused violent fluctuations (by up to ten times) before adaptation took place. Buoyancy differences appeared to mask differences in oxygen uptake of unanaesthetized larvae in similar transfer experiments.There was little tendency for oxygen uptake to become reduced during darkness in either Bergen or Kiel larvae.The effect of age on oxygen uptake (expressed as Qo) was not marked, though there tended to be a peak at, and just after, hatching, with a tendency for a fall off during starvation.

scholarly journals Oxygen availability and embryonic development in sand snail (Polinices sordidus) egg masses

1995 ◽  
Vol 198 (1) ◽  
pp. 241-247 ◽  
Author(s):  
D Booth
Keyword(s):  
Embryonic Development ◽  
Oxygen Tension ◽  
Prolonged Exposure ◽  
Sea Water ◽  
Average Diameter ◽  
Canal System ◽  
Egg Masses ◽  
Hypoxic Conditions ◽  
The Matrix ◽  
Low Levels

The oxygen transport physiology of sand snail Polinices sordidus egg masses was investigated using oxygen microelectrodes and open-flow respirometry. P. sordidus eggs are laid in a jelly matrix that rapidly absorbs water and swells into a horseshoe-shaped sausage. The average diameter of these sausages is 37 mm. Eggs are enclosed in capsules that are distributed throughout the jelly matrix, but 65 % of the eggs are located within 3 mm of the outer surface. There is no circulatory or canal system within the matrix so all gas exchange between developing embryos and the environment must occur by diffusion through the jelly matrix. Oxygen tension in the outer layer remains moderately high (PO2>10 kPa) throughout incubation but decreases rapidly in more centrally located regions, so that by day 4 embryos in this region are exposed to extremely hypoxic conditions (PO2<1 kPa). This hypoxia limits oxygen consumption of embryos to low levels and appears to slow embryonic development or even to arrest it. From day 4 onwards, the central region gradually become less hypoxic because the hatching of peripherally located embryos causes the outer layers of the jelly matrix to disintegrate and thus reduces the diffusion distance for oxygen between the centrally located embryos and the surrounding sea water. As the oxygen tension rises, development accelerates and the embryos eventually hatch as viable veligers, apparently unharmed by their prolonged exposure to hypoxia.

scholarly journals Long-Term Hypoxia Maintains a State of Dedifferentiation and Enhanced Stemness in Fetal Cardiovascular Progenitor Cells

2021 ◽  
Vol 22 (17) ◽  
pp. 9382
Author(s):  
Cole Knox ◽  
Victor Camberos ◽  
Lourdes Ceja ◽  
Andrea Monteon ◽  
Lorelei Hughes ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Early Stage ◽  
Low Oxygen ◽  
Hypoxic Conditions ◽  
Hypoxic Environment ◽  
Cell Mobilization ◽  
Islet 1 ◽  
The Impact

Early-stage mammalian embryos survive within a low oxygen tension environment and develop into fully functional, healthy organisms despite this hypoxic stress. This suggests that hypoxia plays a regulative role in fetal development that influences cell mobilization, differentiation, proliferation, and survival. The long-term hypoxic environment is sustained throughout gestation. Elucidation of the mechanisms by which cardiovascular stem cells survive and thrive under hypoxic conditions would benefit cell-based therapies where stem cell survival is limited in the hypoxic environment of the infarcted heart. The current study addressed the impact of long-term hypoxia on fetal Islet-1+ cardiovascular progenitor cell clones, which were isolated from sheep housed at high altitude. The cells were then cultured in vitro in 1% oxygen and compared with control Islet-1+ cardiovascular progenitor cells maintained at 21% oxygen. RT-PCR, western blotting, flow cytometry, and migration assays evaluated adaptation to long term hypoxia in terms of survival, proliferation, and signaling. Non-canonical Wnt, Notch, AKT, HIF-2α and Yap1 transcripts were induced by hypoxia. The hypoxic niche environment regulates these signaling pathways to sustain the dedifferentiation and survival of fetal cardiovascular progenitor cells.

A CLINICAL CASE OF PRIMARY HYPERPARATHYROIDISM OF THE OSTEO-VISCERAL FORM

2020 ◽  
pp. 155-161
Author(s):  
Poselyugina O.B. ◽  
Kulish A.S. ◽  
Vasiliev D.F.
Keyword(s):  
Primary Hyperparathyroidism ◽  
Clinical Case ◽  
Early Stage ◽  
Diagnostic Errors ◽  
Epidemiological Studies ◽  
Medical Documentation ◽  
Screening Methods ◽  
Internal Organs ◽  
Blood Calcium ◽  
Slow Development

Introduction. Primary hyperparathyroidism is an endocrine disease resulting from a primary pathology of the parathyroid gland, characterized by increased secretion of parathyroid hormone and increased blood calcium levels. Among the endocrine diseases, primary hyperparathyroidism is the third most common after diabetes mellitus and thyroid disease. In Russia, according to epidemiological studies, primary hyperparathyroidism is found in 1% of the population, women suffer 2-3 times more often than men do, and the average age of diagnosis is 54-59 years. In the absence of a timely diagnosis, primary hyperparathyroidism causes systemic damage to internal organs: renal impairment, nephrolithiasis, esophageal affection, cardiovascular and nervous system involvement, and it leads to a violation of bone tissue integrity. The aim is to demonstrate a clinical case of a patient with primary hyperparathyroidism and to analyze the stages of diagnosis of the disease and treatment. Material and methods. The review of medical literature on the problem of diagnostics and treatment of primary hyperparathyroidism was performed, as well as an analysis of the patient’s medical documentation with this pathology. Results and discussion. A variant of complicated course of primary hyperparathyroidism of bone and visceral form is considered. About 15 years passed from the moment of appearance of the first symptoms of the disease to the development of complications of renal and bone system. Despite the slow development of the disease and availability of screening methods, hyperparathyroidism was detected at the stage of complications. This article provides a detailed analysis of the primary hyperparathyroidism history, as well as analyzes the possibilities of diagnosis, treatment and prevention of this pathology. The efficacy of the therapy has been assessed, and ways of correction have been outlined. The analysis of the reasons that made it difficult to diagnose this pathology at an early stage, before the development of serious complications of internal organs, has been carried out. Conclusions: It can be assumed that the presented clinical case will increase the awareness of physicians, especially therapists, about the primary manifestations of this pathology and the peculiarities of its detection and routing the patient, which will allow avoiding many diagnostic errors.

scholarly journals Connectivity Map Analysis Indicates PI3K/Akt/mTOR Inhibitors as Potential Anti-Hypoxia Drugs in Neuroblastoma

Cancers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2809
Author(s):  
Paolo Uva ◽  
Maria Carla Bosco ◽  
Alessandra Eva ◽  
Massimo Conte ◽  
Alberto Garaventa ◽  
...  
Keyword(s):  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Drug Repurposing ◽  
Enrichment Analysis ◽  
Mtor Inhibitors ◽  
Gene Set Enrichment Analysis ◽  
Low Oxygen ◽  
Connectivity Map ◽  
Hypoxic Conditions ◽  
Connectivity Score

Neuroblastoma (NB) is one of the deadliest pediatric cancers, accounting for 15% of deaths in childhood. Hypoxia is a condition of low oxygen tension occurring in solid tumors and has an unfavorable prognostic factor for NB. In the present study, we aimed to identify novel promising drugs for NB treatment. Connectivity Map (CMap), an online resource for drug repurposing, was used to identify connections between hypoxia-modulated genes in NB tumors and compounds. Two sets of 34 and 21 genes up- and down-regulated between hypoxic and normoxic primary NB tumors, respectively, were analyzed with CMap. The analysis reported a significant negative connectivity score across nine cell lines for 19 compounds mainly belonging to the class of PI3K/Akt/mTOR inhibitors. The gene expression profiles of NB cells cultured under hypoxic conditions and treated with the mTORC complex inhibitor PP242, referred to as the Mohlin dataset, was used to validate the CMap findings. A heat map representation of hypoxia-modulated genes in the Mohlin dataset and the gene set enrichment analysis (GSEA) showed an opposite regulation of these genes in the set of NB cells treated with the mTORC inhibitor PP242. In conclusion, our analysis identified inhibitors of the PI3K/Akt/mTOR signaling pathway as novel candidate compounds to treat NB patients with hypoxic tumors and a poor prognosis.

scholarly journals Hypoxia-Induced Gene Expression Occurs Solely through the Action of Hypoxia-Inducible Factor 1α (HIF-1α): Role of Cytoplasmic Trapping of HIF-2α

2003 ◽  
Vol 23 (14) ◽  
pp. 4959-4971 ◽  
Author(s):  
Sang-ki Park ◽  
Agnes M. Dadak ◽  
Volker H. Haase ◽  
Lucrezia Fontana ◽  
Amato J. Giaccia ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcriptional Activity ◽  
Hypoxia Inducible Factor ◽  
Low Oxygen ◽  
Hypoxic Conditions ◽  
Show Evidence ◽  
Dependent Protein ◽  
A Cell ◽  
Cell Type Specific ◽  
Inducible Genes

ABSTRACT The hypoxia-inducible factors 1α (HIF-1α) and 2α (HIF-2α) have extensive structural homology and have been identified as key transcription factors responsible for gene expression in response to hypoxia. They play critical roles not only in normal development, but also in tumor progression. Here we report on the differential regulation of protein expression and transcriptional activity of HIF-1α and -2α by hypoxia in immortalized mouse embryo fibroblasts (MEFs). We show that oxygen-dependent protein degradation is restricted to HIF-1α, as HIF-2α protein is detected in MEFs regardless of oxygenation and is localized primarily to the cytoplasm. Endogenous HIF-2α remained transcriptionally inactive under hypoxic conditions; however, ectopically overexpressed HIF-2α translocated into the nucleus and could stimulate expression of hypoxia-inducible genes. We show that the factor inhibiting HIF-1 can selectively inhibit the transcriptional activity of HIF-1α but has no effect on HIF-2α-mediated transcription in MEFs. We propose that HIF-2α is not a redundant transcription factor of HIF-1α for hypoxia-induced gene expression and show evidence that there is a cell type-specific modulator(s) that enables selective activation of HIF-1α but not HIF-2α in response to low-oxygen stress.

The Effects of External Salinity on the Drinking Rates of the Larvae of Herring, Plaice and Cod

1988 ◽  
Vol 138 (1) ◽  
pp. 1-15 ◽  
Author(s):  
P. TYTLER ◽  
J. H. BLAXTER
Keyword(s):  
Time Course ◽  
Gadus Morhua ◽  
Sea Water ◽  
Fluorescein Isothiocyanate ◽  
Yolk Sac ◽  
Clupea Harengus ◽  
Larval Stages ◽  
First Feeding ◽  
Fluorescein Isothiocyanate Dextran ◽  
External Salinity

Drinking responses to salinity change in the larvae of herring (Clupea harengus L.), plaice (Pleuronectes platessa L.) and cod (Gadus morhua L.) were measured from the time course of uptake of dextran labelled with tritium, following immersion in solutions of 32‰ and 16‰ sea water. The yolk sac and first feeding larval stages of all three species drink in both salinities. Furthermore, post-yolk sac stages appear to adjust their drinking rates to compensate for different salinities in a manner similar to that of the adults. Drinking rates in 32‰ sea water are approximately double those in 16‰. Mass-related drinking rates of larvae are higher than those in adults, but the differences do not match the differences in surface area to mass ratios, suggesting that larval skin is less permeable to water than is adult gill epithelium. Water absorption is indicated by the evidence of concentration of dextran in the gut. The estimates of drinking rates from tritiated dextran uptake are supported by epifluorescence microscopical measurements of the uptake of fluorescein isothiocyanate dextran.

Jasus lalandii 'walkouts' or mass strandings in South Africa during the 1990s: an overview

2001 ◽  
Vol 52 (8) ◽  
pp. 1085 ◽  
Author(s):  
Andrew C. Cockcroft
Keyword(s):  
South Africa ◽  
West Coast ◽  
The Other ◽  
Fishing Industry ◽  
Low Oxygen ◽  
Rock Lobster ◽  
The West ◽  
Hypoxic Conditions ◽  
Oxygen Conditions ◽  
Mass Mortalities

Faunal mass mortalities are a sporadic, but not uncommon, feature of the West and South coasts of South Africa. Five mass mortalities of West Coast rock lobsterJasus lalandii, including three of the most severe ever recorded in South Africa, occurred in the 1990s and resulted in the stranding of about 2263 tonnes of lobster. The bulk (97%) of the loss occurred in the last three years of the decade. The five events occurred within an 80 km stretch of coastline that straddled two fishing zones and resulted from hypoxic conditions associated with highbiomass dinoflagellate blooms. In each case, the quantity of lobsters stranded was directly related to the extent or duration of low-oxygen conditions. Small females constituted the bulk of the lobster stranded in most events. The lobster fisheries in the affected fishing zones suffered severe impacts. Recovery in one zone appears to be extremely slow, whereas the other zone is more resilient. Not only would a continuation of the trend of increasing frequency and severity of lobster strandings devastate the rock-lobster fishing industry and the employment prospects of small fishing communities, but it could also seriously affect the ecology of the region.

scholarly journals The Response of Macrophages and Neutrophils to Hypoxia in the Context of Cancer and Other Inflammatory Diseases

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Antje Egners ◽  
Merve Erdem ◽  
Thorsten Cramer
Keyword(s):  
Endothelial Cells ◽  
Inflammatory Diseases ◽  
Neutrophil Function ◽  
Proper Function ◽  
Low Oxygen ◽  
Bacterial Killing ◽  
Molecular Responses ◽  
Chronic Inflammatory Diseases ◽  
Hypoxic Conditions ◽  
Cellular Components

Lack of oxygen (hypoxia) is a hallmark of a multitude of acute and chronic diseases and can be either beneficial or detrimental for organ restitution and recovery. In the context of inflammation, hypoxia is particularly important and can significantly influence the course of inflammatory diseases. Macrophages and neutrophils, the chief cellular components of innate immunity, display distinct properties when exposed to hypoxic conditions. Virtually every aspect of macrophage and neutrophil function is affected by hypoxia, amongst others, morphology, migration, chemotaxis, adherence to endothelial cells, bacterial killing, differentiation/polarization, and protumorigenic activity. Prominent arenas of macrophage and neutrophil function, for example, acute/chronic inflammation and the microenvironment of solid tumors, are characterized by low oxygen levels, demonstrating the paramount importance of the hypoxic response for proper function of these cells. Members of the hypoxia-inducible transcription factor (HIF) family emerged as pivotal molecular regulators of macrophages and neutrophils. In this review, we will summarize the molecular responses of macrophages and neutrophils to hypoxia in the context of cancer and other chronic inflammatory diseases and discuss the potential avenues for therapeutic intervention that arise from this knowledge.

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