The effect of the acanthocephalan Pomphorhynchus laevis upon the respiration of its intermediate host, Gammarus pulex

Parasitology ◽  
1974 ◽  
Vol 68 (2) ◽  
pp. 271-284 ◽  
Author(s):  
A. E. Rumpus ◽  
C. R. Kennedy

The respiration rates of individual Gammarus pulex infected by larval Pomphorhynchus laevis were investigated with particular reference to the stage of development of the host and parasite and to the water temperature. At 20°C the oxygen consumption of Gammarus of all sizes was reduced by an average of 19·3 % by the presence of cystacanths of the parasite, but was unaffected by the presence of acanthellae. It is considered that the small size of this larval stage, in relation to that of its host, is responsible for the failure to detect an effect. Multiple infections did not exert any greater effect upon host respiration than single cystacanths, nor did it appear that the parasite had different effects upon hosts of different sexes. At 10°C no significant differences were observed between the respiration rates of infected and uninfected gammarids. The parasite was probably still depressing the host respiration rate at this temperature, but the oxygen uptake of G. pulex is so low that the differences between infected and uninfected individuals were too small to be detected. The parasite has a direct effect upon the physiological processes of the host, but neither the mechanism of this nor the reasons for the different effects found in different host-parasite systems are yet understood. Despite the pronounced effect of P. laevis on respiration of individual hosts, its effect upon the oxygen consumption of a natural host population is small since only a small proportion of the population carries infections and water temperatures remain below 10°C for over half the year.

1989 ◽  
Vol 67 (7) ◽  
pp. 1613-1619 ◽  
Author(s):  
William A. Walsh ◽  
William A. Lund Jr.

Oxygen consumption rates of individual eggs of the grubby, Myoxocephalus aenaeus, and the longhorn sculpin, Myoxocephalus octodecemspinosus, were determined by microrespirometry. Eggs of both species were incubated in temperature – salinity combinations (grubby: in 2, 5, 8 °C at 10, 12.5, 15, 20, 25, 30, 35 parts per thousand (ppt); longhorn sculpin: in 2, 5, 8 °C at 15, 17.5, 20, 25, 30, 35 ppt) to determine the effects of these abiotic factors and development on oxygen consumption rates. Respiration rates of eggs of both species were not affected significantly by constant salinities. Multiple regression analyses demonstrated that the natural logarithms of oxygen uptake rates increased linearly with the temperature – age (in hours after fertilization) interaction and parabolically with age in both species. Oxygen consumption rates increased at hatching. Acute salinity changes did not affect embryonic oxygen consumption by either species. An acute temperature increase, however, elicited increased oxygen uptake by longhorn sculpin embryos (Q10 = 2.56).


2009 ◽  
Vol 276 (1676) ◽  
pp. 4229-4236 ◽  
Author(s):  
Stéphane Cornet ◽  
Nathalie Franceschi ◽  
Loïc Bollache ◽  
Thierry Rigaud ◽  
Gabriele Sorci

Parasites often manipulate host immunity for their own benefit, either by exacerbating or suppressing the immune response and this may directly affect the expression of parasite virulence. However, genetic variation in immunodepression, which is a prerequisite to its evolution, and the relationship between immunodepression and virulence, have rarely been studied. Here, we investigated the variation among sibships of the acanthocephalan parasite, Pomphorhynchus laevis , in infecting and in immunodepressing its amphipod host, Gammarus pulex . We also assessed the covariation between infectivity, parasite-induced immune depression and host mortality (parasite virulence). We found that infectivity, the intensity of immunodepression and virulence were variable among parasite sibships. Infectivity and the level of immunodepression were not correlated across parasite sibships. Whereas infectivity was unrelated to host mortality, we found that gammarids that were exposed to the parasite sibships that immunodepressed their hosts the most survived better. This positive covariation between host survival and immunodepression suggests that gammarids exposed to the less immunodepressive parasites could suffer from damage imposed by a higher activity of the phenoloxidase.


1982 ◽  
Vol 202 (3) ◽  
pp. 661-665 ◽  
Author(s):  
D G Clark ◽  
M Brinkman ◽  
O H Filsell ◽  
S J Lewis ◽  
M N Berry

(Na+ + K+)-dependent ATPase activity, heat production and oxygen consumption were increased by 59%, 62% and 75% respectively in hepatocytes from tri-iodothyronine-treated rats. Ouabain at concentrations of 1 and 10 mM decreased oxygen uptake by 2-8% in hepatocytes from euthyroid rats and by 5-15% in hepatocytes from hyperthyroid animals. Heat output was decreased by 4-9% with the glycoside in isolated liver parenchymal cells from the control animals and by 11% in the cells from the tri-iodothyronine-treated animals. These results do not support the hypothesis that hepatic (Na+ + K+)-ATPase plays a major role in increased heat production in hepatocytes from hyperthyroid rats.


2001 ◽  
Vol 79 (4) ◽  
pp. 554-561 ◽  
Author(s):  
Shawn Meagher ◽  
Timothy P O'Connor

The effects of parasites on their hosts can vary among host populations, but few studies have examined geographic variation in host-parasite interactions. We examined the effects of Capillaria hepatica (Nematoda) infection on deer mice (Peromyscus maniculatus gracilis) from two different populations. Specifically, we measured the basal metabolic rate (BMR), cold-stress maximum oxygen consumption (MRpeak), metabolic scope (MRpeak/BMR), and thermogenic endurance of infected and uninfected mice from one population with, and a second population without, a history with C. hepatica. Infection had no effect on BMR, but did have effects on cold-stress measures. A previous study documented a significant relationship between survival and MRpeak in wild deer mice; hence, the effects of infection on the parameters that we measured could influence fitness. Only mice that had no historical association with C. hepatica displayed negative consequences of infection, which suggests that the historical host population has evolved mechanisms to cope with infection. Models of the evolution of virulence should include evolutionary responses of both hosts and parasites, particularly when systems involve macroparasites that have long generation times.


1999 ◽  
Vol 73 (2) ◽  
pp. 95-102 ◽  
Author(s):  
B.S. Dezfuli ◽  
E. Rossetti ◽  
C.M. Bellettato ◽  
B.J. Maynard

Infection rates of larvalPomphorhynchus laevisMu¨ller, 1776 (Acanthocephala) were studied in its intermediate hostEchinogammarus stammeriS. Karaman, 1931 (Amphipoda). Crustaceans were collected monthly, from July 1990 to July 1997, at two sites on the River Brenta (northern Italy). Of over 50,000E. stammeriexamined, more than 24% were parasitized withP. laevislarvae. The differences in the prevalence of infection between the two stations were significant. The intensity of infection varied from one to 15 acanthocephalans per host. Amphipods with multiple infections constituted 28–32% of each monthly sample. During the 7 years of investigation, the prevalence of infection typically reached its highest and lowest levels in the summer and spring months, respectively. Acanthocephalan larvae showed no preference for host sex. Infected ovigerous females ofE. stammeriwere found carrying eggs or juveniles in their brood pouches, but had fewer and smaller eggs.Pomphorhynchus laevislarvae co-occurred withAcanthocephalus clavula(Dujardin, 1845) and also with the tapewormCyathocephalus truncatus(Pallas, 1781) in the same host.


2008 ◽  
Vol 68 (1) ◽  
pp. 115-122 ◽  
Author(s):  
MB. Cunha-Santino ◽  
SP. Gouvêa ◽  
I. Bianchini Jr ◽  
AAH. Vieira

This study aimed to discuss and describe the oxygen consumption during aerobic mineralization of organic products (cells and excretion products) from five unialgal cultures: Cryptomonas sp., Microcystis aeruginosa, Anabaena spiroides, Thalassiosira sp. and Aulacoseira granulata. These species were isolated from Barra Bonita reservoir (22º 29’ S and 48º 34’ W) and cultivated in the laboratory. From each culture, two decomposition chambers were prepared; each chamber contained about 130 mg.L-1 of carbon from water samples of the reservoir. The chambers were aerated and incubated in the dark at 20.0 ºC. The concentration of dissolved oxygen, pH values and electrical conductivity of the solutions were determined during a period of 10 days. The results indicated increases in oxygen consumption for all the solutions studied and also for electrical conductivity. The pH values presented a decreasing tendency throughout the experiment. Oxygen consumption varied from 43 (Aulacoseira granulata chamber) to 345 mg O2 g-1 C (Anabaena spiroides chamber). Decrease in pH values was probably due to increase in CO2 concentration from microbial respiration. Increase in electrical conductivity might be due to the liberation of ions during decomposition. The results demonstrate the potentiality of the studied genera in influencing oxygen availability followed by a die-off event. It also indicates the possibility of changing of the electrical conductivity and pH values in the water column due the aerobic algae mineralization.


1941 ◽  
Vol 18 (2) ◽  
pp. 153-161
Author(s):  
J. R. ERICHSEN JONES

The suggestion has been put forward that the oligodynamic action of certain heavy metals is the result of the destruction or inactivation of substances essential for cellular respiration. In a study of the effect of copper sulphate solutions on the oxygen consumption of Polycelis nigra it is found that solutions of concentration 0.001-0.01 N, fatal in 2 hr. or less, induce a marked preliminary rise in the respiration rate; this appears to be due to the inhibition of ciliary locomation and increased muscular activity. A similar increase is produced by increasing the activity of the animals by mechanical means, or by a muscle stimulant (barium chloride). Over the latter part of the survival time the respiration rate drops rapidly and disintegration of the animals begins when it falls to about 60% of the normal value. A 0.0004 N copper sulphate solutions does not inhibit ciliary locomotion, does not stimulate muscular activity, and the oxygen consumption undergoes a stedy decline. A 0.0002 N NaCN solution rapidly depresses the respiration rate to less than 20% of the normal value, but is not fatal, the animals surviving over 4 days. Hydrogen ions, at the concentrations resulting from the hydrolysis of the salt, have no appreciable effect on the oxygen consumption, but at lethal concentrations (pH 2.6, 2.8) effect a speedy depression. The results suggest that the depression of respiration rate observed is insufficient to account for the death of the animals, and is no more than a symptom of the toxic process. A similar general result was obtained in experiments with silver nitrate and mercuric chloride, and also in experiments on the comparative effect of copper sulphate and sodium cyanide solutions on the oxygen consumption of Gammarus pulex.


2011 ◽  
pp. S177-S184 ◽  
Author(s):  
Z. KOJIC ◽  
K. GOPCEVIC ◽  
D. MARINKOVIC ◽  
G. TASIC

Angiotensin converting enzyme inhibitors are widely used in therapy of cardiovascular diseases. However, the consensus on effects of these inhibitors in control of myocardial oxygen consumption during the process of experimental hypercholesterolemia and under the condition of endothelial dysfunction has not been reached. Here we examined effects of captopril, an angiotensin converting enzyme inhibitor, on serum lipid levels and oxygen consumption rate in mitochondria isolated from heart of rabbits treated by hypercholesterolemic diet. During the twelve-week period, the Chinchilla male rabbits were daily treated by saline (controls); 1 % cholesterol diet; 5 mg/kg/day captopril or 1 % cholesterol + 5 mg/kg/day captopril. Total- and high-density lipoprotein cholesterol and triglyceride in serum were measured spectrophotometricly. The left ventricle mitochondrial fraction was isolated and myocardial oxygen consumption was measured by Biological Oxygen Monitor. Mitochondria isolated from hearts of rabbits exposed to hypercholesterolemic diet showed significantly reduced respiration rates (state 3 and state 4) with altering adenosine diphosphate/oxygen ratio, whereas the respiratory control ratio was not affected when compared to controls. Mitochondria from cholesterol/captopril–treated animals showed significantly reduced respiration rates without altering adenosine diphosphate/oxygen ratio index or respiratory control ratio. Although captopril did not exert the favorable effect on serum lipid levels in cholesterol-treated animals, it restored the mitochondrial oxygen consumption. Further studies should be performed to define the underlying physiological and/or pathophysiological mechanisms and clinical implications.


1991 ◽  
Vol 69 (9) ◽  
pp. 2410-2413 ◽  
Author(s):  
J. Mallefet ◽  
F. Baguet

Modifications in oxygen consumption and luminescence of isolated luminescent organs of the mesopelagic fish Argyropelecus hemigymnus following glucose and pyruvate administration were studied before and during light emission triggered by adrenaline. Isolated photophores (mean fresh weight 13.5 ± 0.9 mg) at rest, i.e., in the absence of light emission, in saline (20 °C) exhibit a respiration rate of 1.045 ± 0.082 (SE) nmol O2/min (n = 35). A significant decrease (p = 0.05) in oxygen consumption was observed after the addition of 5.5 mM glucose. Instead of the oxygen decrease usually observed as a result of control stimulations using adrenaline, photophores pretreated with glucose increased their oxygen uptake in response to adrenaline, and maximal light emission was reduced by 85% (p = 0.01). The addition of 5.5 mM pyruvate induced a significant transient increase (p = 0.05) in oxygen uptake of isolated photophores, though this treatment did not statistically modify the mean time course of oxygen consumption and light emission in response to adrenaline. The hypothesis of a hypometabolic state of the isolated photophores of A. hemigymnus during light emission is discussed.


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