Responses to Hypersaline Exposure in the Euryhaline Crayfish PAcifastacus Leniusculus: II. Modulation of Haemocyanin Oxygen Binding In Vitro and In Vivo

1982 ◽  
Vol 99 (1) ◽  
pp. 447-467
Author(s):  
MICHÈLE G. WHEATLY ◽  
B. R. MCMAHON
Keyword(s):  
Salt Effect ◽  
Ionic Composition ◽  
Inorganic Ions ◽  
Pacifastacus Leniusculus ◽  
Oxygen Binding ◽  
Complete Saturation ◽  
O2 Delivery ◽  
O2 Binding

The effect of 48 h of hypersaline exposure (25, 50 and 75% SW) on haemocyanin oxygenation properties in the euryhaline crayfish Pacifastacus leniusculus was investigated in vitro and in vivo. In vitro significant increases in affinity and cooperativity were measured, although the magnitude of the Bohr shift was unaffected. In vitro dialysis of haemolymph against physiological salines of variable ionic composition proved that these changes were only partly attributable to altered levels of haemolymph ions, implicating the existence of modulators other than H+ and inorganic ions, the possible identities of which are discussed. Significant depressions of both pre- and postbranchial oxygen tensions (Pv, Ov, O2 and Pa, Oa, O2) were observed, but O2 delivery was maintained by utilization of the venous reserve and by an increase in haemocyanin O2 affinity. This occurred despite a concomitant acidosis whose effect on O2 affinity was directly opposed by the ‘salt’ effect. Under hypersaline conditions, haemocyanin played an increasingly important role in O2 delivery in vivo. Despite a reduction in the concentration of combined O2 at complete saturation of the pigment (CmaxHCyOHCyO2). indicating lowered haemocyanin concentration, compensatory changes in O2-binding and cardiac output precluded an impairment to O2 transfer. Equilibration at the tissues (Et,Ot,O2) in FW was less effective than at the gills (Eb,Ob,O2 but progressively improved with hypersaline exposure reversing this trend. Although effects of increased salinity on O2 equilibrium characteristics were qualitatively similar in vivo and in vitro, some interesting quantitative differences are discussed.

The archaeogastropod mollusc Haliotis iris: tissue and blood metabolites and allosteric regulation of haemocyanin function

2002 ◽  
Vol 205 (2) ◽  
pp. 253-263
Author(s):  
Jane W. Behrens ◽  
John P. Elias ◽  
H. Harry Taylor ◽  
Roy E. Weber
Keyword(s):  
Equilibrium Constants ◽  
Adductor Muscle ◽  
Interactive Effects ◽  
Oxygen Binding ◽  
Binding Properties ◽  
Adductor Muscles ◽  
Short Term Exposure ◽  
O2 Delivery ◽  
O2 Binding

SUMMARY We investigated divalent cation and anaerobic end-product concentrations and the interactive effects of these substances and pH on haemocyanin oxygen-binding (Hc-O2) in the New Zealand abalone Haliotis iris. During 24 h of environmental hypoxia (emersion), d-lactate and tauropine accumulated in the foot and shell adductor muscles and in the haemolymph of the aorta, the pedal sinus and adductor muscle lacunae, whereas l-lactate was not detected. Intramuscular and haemolymph d-lactate concentrations were similar, but tauropine accumulated to much higher levels in muscle tissues. Repeated disturbance and short-term exposure to air over 3 h induced no accumulation of d- or l-lactate and no change in [Ca2+], [Mg2+], pH and O2-binding properties of the native haemolymph. The haemolymph showed a low Hc-O2 affinity, a large reverse Bohr effect and marked cooperativity. Dialysis increased Hc-O2 affinity, obliterated cooperativity and decreased the pH-sensitivity of O2 binding. Replacing Mg2+ and Ca2+ restored the native O2-binding properties and the reverse Bohr shift. l- and d-lactate exerted minor modulatory effects on O2-affinity. At in vivo concentrations of Mg2+ and Ca2+, the cooperativity is dependent largely on Mg2+, which modulates the O2 association equilibrium constants of both the high-affinity (KR) and the low-affinity (KT) states (increasing and decreasing, respectively). This allosteric mechanism contrasts with that encountered in other haemocyanins and haemoglobins. The functional properties of H. iris haemocyanin suggest that high rates of O2 delivery to the tissues are not a priority but are consistent with the provision of a large O2 reserve for facultatively anaerobic tissues during internal hypoxia associated with clamping to the substratum.

scholarly journals Seminal Plasma: Relevant for Fertility?

2021 ◽  
Vol 22 (9) ◽  
pp. 4368
Author(s):  
Heriberto Rodriguez-Martinez ◽  
Emilio A. Martinez ◽  
Juan J. Calvete ◽  
Fernando J. Peña Vega ◽  
Jordi Roca
Keyword(s):  
Seminal Plasma ◽  
Current Knowledge ◽  
Inorganic Ions ◽  
Vitro Fertilization ◽  
Dna And Rna ◽  
Model Animal ◽  
Sexual Glands ◽  
Species Specific

Seminal plasma (SP), the non-cellular component of semen, is a heterogeneous composite fluid built by secretions of the testis, the epididymis and the accessory sexual glands. Its composition, despite species-specific anatomical peculiarities, consistently contains inorganic ions, specific hormones, proteins and peptides, including cytokines and enzymes, cholesterol, DNA and RNA—the latter often protected within epididymis- or prostate-derived extracellular vesicles. It is beyond question that the SP participates in diverse aspects of sperm function pre-fertilization events. The SP also interacts with the various compartments of the tubular genital tract, triggering changes in gene function that prepares for an eventual successful pregnancy; thus, it ultimately modulates fertility. Despite these concepts, it is imperative to remember that SP-free spermatozoa (epididymal or washed ejaculated) are still fertile, so this review shall focus on the differences between the in vivo roles of the SP following semen deposition in the female and those regarding additions of SP on spermatozoa handled for artificial reproduction, including cryopreservation, from artificial insemination to in vitro fertilization. This review attempts, including our own results on model animal species, to critically summarize the current knowledge of the reproductive roles played by SP components, particularly in our own species, which is increasingly affected by infertility. The ultimate goal is to reconcile the delicate balance between the SP molecular concentration and their concerted effects after temporal exposure in vivo. We aim to appraise the functions of the SP components, their relevance as diagnostic biomarkers and their value as eventual additives to refine reproductive strategies, including biotechnologies, in livestock models and humans.

PRO-INFLAMMATORY MOLECULAR AND INFLAMMATORY MECHANISMS OF SULFUR METABOLISM IN IBD-RELEVANT CLOSTRIDIA SPECIES

2021 ◽  
Vol 27 (Supplement_1) ◽  
pp. S30-S31
Author(s):  
Gabriel Suarez ◽  
Bo Liu ◽  
Jeremy Herzog ◽  
Ryan Sartor
Keyword(s):  
Sulfur Metabolism ◽  
Cellular Respiration ◽  
Bile Acid Metabolism ◽  
Bile Salt Hydrolase ◽  
Oxygen Binding ◽  
Bacterial Strains ◽  
Healthy Human ◽  
H2s Production

Abstract Sulfur metabolism is emerging as a signature of IBD gut microbiota. Overrepresentation of sulfur-reducing bacteria (SRB) in IBD results in SRB-derived epithelial toxic H2S production that can overwhelm the body’s detoxification capacity, leading to impaired cellular respiration by inhibiting oxygen binding to mitochondrial cytochrome-c-oxidase. Butyrate potently inhibits SRBs and H2S, yet IBD patients have reduced short chain fatty acid (SCFA) production. More critically, H2S blocks butyrate oxidation, the primary energy source of colonocytes; butyrate oxidation deficiency is a defining characteristic of IBD. Since cysteine is the preferred substrate for H2S production by SRBs, a cysteine-rich environment provided by either a high protein diet or local intestinal mucus degradation promotes ideal conditions for SRB establishment and proliferation. SRBs can catabolize other sulfur-containing compounds critical for immune homeostasis and cellular health, such as taurine-conjugated bile acids and the “master antioxidant” glutathione, leading to further toxic H2S production. However, the molecular underpinnings of sulfur metabolism by specific bacterial genera is understudied in IBD. Results: Using a combination of in-vivo and in-vitro screening to detect the relative induction of interleukin 10 (IL-10) and interferon g (IFNg) by 19 resident bacterial strains isolated from a healthy human donor, we identified 4 bacterial strains that induce a low IL-10/IFNg ratio. These 4 strains (low group), but not 3 bacterial strains that induce a high IL-10/IFNg ratio, induce colitis in selectively colonized gnotobiotic Il10-/- mice (Fig.1A). Two of these 4 disease-inducing strains, Clostridium perfringens (A12) and Clostridium bolteae (B6), produce high concentrations of H2S in monoassociated mice (Fig.1B). In-vitro H2S production by these strains is dependent on cysteine (Fig.1C). C. perfringens and C. bolteae each induce colitis in monoassociated Il10-/- mice (Fig.1D). We are dissecting the sulfur metabolic pathways in C. perfringens and C. bolteae and their contribution to inflammatory processes by interrupting key genes predicted to contribute to H2S production, cysteine catabolism and bile acid metabolism. We will use these mutants in both in-vitro and in-vivo Il10 -/- gnotobiotic mice models to characterize their metabolic and inflammatory profiles. We have created several mutants using Targetron gene editing, including the dissimilatory sulfate reductase (Δdsr), a putative sulfonate membrane transporter (ΔssuA), anaerobic sulfite reductase (ΔasrA) and bile salt hydrolase (Δbsh). Conclusions: H2S producing bacterial strains can induce experimental colitis. Our planned mechanistic studies will determine the metabolic routes for H2S production by specific aggressive bacteria to guide novel therapeutic or dietary interventions to improve IBD prognosis.

scholarly journals A gC1qR Prevents White Spot Syndrome Virus Replication in the Freshwater Crayfish Pacifastacus leniusculus

2010 ◽  
Vol 84 (20) ◽  
pp. 10844-10851 ◽  
Author(s):  
Apiruck Watthanasurorot ◽  
Pikul Jiravanichpaisal ◽  
Irene Söderhäll ◽  
Kenneth Söderhäll
Keyword(s):  
Cell Culture ◽  
Viral Replication ◽  
White Spot Syndrome Virus ◽  
Pacifastacus Leniusculus ◽  
White Spot ◽  
Tissue Cell ◽  
Freshwater Crayfish ◽  
White Spot Syndrome

ABSTRACT The gC1qR/p32 protein is a multiple receptor for several proteins and pathogens. We cloned a gC1qR homologue in a crustacean, Pacifastacus leniusculus, and analyzed the expression of P. leniusculus C1qR (PlgC1qR) in various tissues. The gC1qR/p32 transcript was significantly enhanced by white spot syndrome virus (WSSV) infection 6 h after viral infection both in vitro in a hematopoietic tissue cell culture (Hpt) and in vivo compared to appropriate controls. Moreover, PlgC1qR silencing in both the Hpt cell culture and live crayfish enhanced the WSSV replication. In addition, by making a recombinant PlgC1qR protein we could show that if this recombinant protein was injected in a crayfish, Pacifastacus leniusculus, followed by injection of WSSV, this significantly reduced viral replication in vivo. Furthermore, if the recombinant PlgC1qR was incubated with Hpt cells and then WSSV was added, this also reduced viral replication. These experiments clearly demonstrate that recombinant PlgC1qR reduce WSSV replication both in vivo and in vitro. The results from a far-Western overlay and glutathione S-transferase pull-down assays showed that PlgC1qR could bind to VP15, VP26, and VP28. Altogether, these results demonstrate a role for PlgC1qR in antiviral activity against WSSV.

scholarly journals Haemolymph Acid-Base, Electrolyte and Gas Status during Sustained Voluntary Activity in the Land Hermit Crab (Coenobita Compressus)

1986 ◽  
Vol 125 (1) ◽  
pp. 225-243
Author(s):  
Michéle G. Wheatly ◽  
Brian R. Mcmahon ◽  
Warren W. Burggren ◽  
Alan W. Pinder
Keyword(s):  
Hermit Crab ◽  
Oxygen Binding ◽  
Acid Base Balance ◽  
Acid Base ◽  
Voluntary Activity ◽  
Binding Characteristics ◽  
Base Balance ◽  
External Water ◽  
O2 Delivery

After 3h(50 m) of voluntary walking, the haemolymph pH of the land hermit crab Coenobita compressus (H. Milne Edwards) decreased by 0.4units. This was accompanied by increases in CO2 tension (Pcoco2). bicarbonate (HCO3− + CO32-) and lactate concentrations. The hypercapnic acidosis was partially compensated by metabolic bicarbonate accumulation and an H+ deficit developed. Unloaded crabs accumulated less of a proton load than crabs transporting mollusc shells. During activity, oxygenation of the haemocyanin (HCy) accounted for the release of 0.3 mmol CO2l−1, via the Haldane effect, which was seven times more than in settled crabs. Control acid-base balance was re-established within 1 h of recovery. At this time, acidic equivalents were excreted at a mean flux rate of 5 mequiv kg−1 h−1 into a source of external water. [Na+] and the ratio of [Na+]:[Cl−] increased during exercise. Coenobita haemolymph had a high O2-carrying capacity (CmaxHCyOHCyO2 = l.55 mmol 1−1). HCy oxygen-binding characteristics were typical of other decapods (φ= −0.44), yet no lactate sensitivity was apparent. Settled in vivo values of O2 tension (Poo2) and content (Coo2) were located around the half-saturation tension (P50) of the dissociation curve. During exercise, POO2 increased and an unopposed Bohr shift decreased the O2-binding affinity, thereby reducing postbranchial saturation. Quantitatively, however, compensations in cardiac output (V·b) were more instrumental in increasing the O2 delivery to respiring tissues. During recovery, haemolymph POO2 remained high and the venous reserve doubled.

scholarly journals EQUALITY OF THE IN VIVO AND IN VITRO OXYGEN-BINDING CAPACITY OF HAEMOGLOBIN IN PATIENTS WITH SEVERE RESPIRATORY DISEASE

1981 ◽  
Vol 53 (12) ◽  
pp. 1325-1328 ◽  
Author(s):  
E. DOMÍNGUEZ DE VILLOTA ◽  
M.T. GARCÍA CARMONA ◽  
J.J. RUBIO ◽  
S. RUIZ DE ANDRÉS
Keyword(s):  
Respiratory Disease ◽  
Binding Capacity ◽  
Oxygen Binding

scholarly journals Modulation of Haemocyanin Oxygen-Affinity by L-Lactate and Urate in the Prawn Penaeus Japonicus

1989 ◽  
Vol 147 (1) ◽  
pp. 133-146 ◽  
Author(s):  
F. LALLIER ◽  
J. P. TRUCHOT
Keyword(s):  
Lactate Concentration ◽  
Oxygen Affinity ◽  
Hypoxic Exposure ◽  
Oxygen Binding ◽  
Maximum Increase ◽  
Penaeus Japonicus ◽  
In Vitro Effects ◽  
Hypoxia Acclimation

The addition of either L-lactate or urate to dialysed haemolymph from the prawn Penaeus japonicus (Bate) increased the in vitro haemocyanin oxygenaffinity. The quantitative values of these two effects, expressed as ΔlogP50/Δlog[effector], were found to be −0.077 for L-lactate and −0.032 for urate, at pH7.6 and 25°C. The normal, significant Bohr effect (ΔlogP50/ΔpH approx. −1.5 at pH7.6, 25°C) was not modified by the two effectors tested, nor was the cooperativity of haemocyanin oxygen-binding (n50 approx. 4). Hypoxic exposure of the prawns to PwOO2: =6.3 or 4.4 kPa (1 kPa=7.5 mmHg) for up to 48 h at 25°C induced only a small, less than 2.5-fold, elevation of L-lactate concentration in the haemolymph, all values remaining below 0.5 mmol I−1, but urate concentration increased to a greater extent (12-fold maximum increase from 0.01 to 0.12 mmol I−1). Haemocyanin oxygen-affinity, measured in vitro on haemolymph samples drawn from hypoxic prawns, increased slightly during the first 3h of hypoxia acclimation (ΔP50=0.8-0.9 kPa at pH 7.6), returning to near normoxic control values after a 48 h hypoxic exposure. The respective roles of L-lactate and urate in enhancing oxygen transport during hypoxia are discussed on the basis of their in vitro effects on haemocyanin oxygenaffinity and their in vivo concentration variations in haemolymph.

scholarly journals Nuclear Ssr4 Is Required for the In Vitro and In Vivo Asexual Cycles and Global Gene Activity of Beauveria bassiana

mSystems ◽  
2020 ◽  
Vol 5 (2) ◽  
Author(s):  
Wei Shao ◽  
Qing Cai ◽  
Sen-Miao Tong ◽  
Sheng-Hua Ying ◽  
Ming-Guang Feng
Keyword(s):  
Chromatin Remodeling ◽  
Inorganic Ions ◽  
Global Gene Expression ◽  
Gene Activity ◽  
Fungal Genome ◽  
Cellular Events ◽  
First Time

Ssr4 is known to serve as a cosubunit of chromatin-remodeling SWI/SNF and RSC complexes in yeasts but has not been functionally characterized in fungi. This study unveils for the first time the pleiotropic effects caused by deletion of ssr4 and its role in mediating global gene expression in a fungal insect pathogen. Our findings confirm an essential role of Ssr4 in hydrophobin biosynthesis and assembly required for growth, differentiation, and development of aerial hyphae for conidiation and conidial adhesion to insect surface and its essentiality for insect pathogenicity and virulence-related cellular events. Importantly, Ssr4 can regulate nearly one-fourth of all genes in the fungal genome in direct and indirect manners, including dozens involved in gene activity and hundreds involved in metabolism and/or transport of carbohydrates, amino acids, lipids, and/or inorganic ions. These findings highlight a significance of Ssr4 for filamentous fungal lifestyle.

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