THE RELATIONSHIP BETWEEN INTRACELLULAR pH AND SWIMMING PERFORMANCE OF BROWN TROUT EXPOSED TO NEUTRAL AND SUBLETHAL pH

1993 ◽  
Vol 176 (1) ◽  
pp. 271-284 ◽  
Author(s):  
P. J. Butler ◽  
N. Day
Keyword(s):  
Intracellular Ph ◽  
Brown Trout ◽  
Swimming Performance ◽  
Plasma Catecholamines ◽  
Muscle Fibres ◽  
Arterial Pco2 ◽  
Neutral Ph ◽  
Red Muscle ◽  
The Relationship ◽  
A Current

Adult brown trout were acclimated for 2–4 weeks to artificial soft water ([Ca2+] 25 micromolar) at neutral pH and at summer (15°C) temperature. During this period they swam against a current of approximately 0.25 m s-1. They then had their dorsal aorta cannulated and were exposed to neutral or sublethal pH (4.5) for 4 days in still water. After 4 days of exposure to sublethal pH, critical swimming speed (Ucrit) was 35 % lower than that for fish at neutral pH. There were significant increases in arterial PCO2 and in blood lactate concentrations at Ucrit compared with the values in resting fish at neutral pH and these led to significant reductions in plasma pH. There were no such changes in fish at sublethal pH. There were no significant changes in intracellular pH (pHi) of red blood cells at Ucrit, probably as a result of increases in the levels of plasma catecholamines. There were significant reductions in pHi of red and white muscle fibres at Ucrit. It is argued that these values were not as low in the white fibres as those seen in previous studies after fish have been chased to exhaustion and, therefore, that the fish in the present study were not completely exhausted, although they would no longer swim at a steady speed. As pHi of the red muscle was the same at Ucrit for fish at neutral and at sublethal pH, it is suggested that Ucrit (fatigue) coincides with a particular pHi of the red muscles and possible mechanisms are discussed.

scholarly journals Interactive Effects of Seasonal Temperature and Low pH on Resting Oxygen Uptake and Swimming Performance of Adult Brown Trout Salmo Trutta

1992 ◽  
Vol 165 (1) ◽  
pp. 195-212 ◽  
Author(s):  
P. J. BUTLER ◽  
N. DAY ◽  
K. NAMBA
Keyword(s):  
Oxygen Uptake ◽  
Brown Trout ◽  
Swimming Performance ◽  
Low Ph ◽  
Swimming Activity ◽  
Acid Water ◽  
Muscle Fibres ◽  
Seasonal Temperature ◽  
Neutral Ph ◽  
Red Muscle

Adult brown trout were acclimated for 2–4 weeks to artificial, soft water (Ca2+ 25μmoll−1) at neutral pH and at summer (15°C) or winter (5°C) temperatures. During this period they swam against a current of approximately 0.25 ms−1. They were then exposed to neutral or sublethal pH for 4 days in still water. For fish with their dorsal aorta catheterized, sublethal pH was 4 at 5°C and 4.5 at 15°C. After 4 days of exposure to sublethal pH, resting oxygen uptake (Mo2 w a s 40 % higher than that at neutral pH for fish held at 15°C and 38 % higher for fish held at 5°C. Critical swimming speeds (Ucrit), in contrast, were 35% and 31% lower, respectively. These two phenomena may be related in as much as the ‘metabolic cost’ of exposure to low pH may increase as swimming speed increases, thus reducing the scope for activity. Another important factor could be an impairment of oxygen delivery to the red muscle fibres. Although arterial O2 concentrations and heart rate are both similar for fish at Ucrit in neutral and acid water, there are signs of haemoconcentration in fish exposed to low pH, and the consequent increase in blood viscosity could disrupt the local circulation in the red fibres. Whatever its causes, an impairment of swimming activity resulting from exposure to acid water may have severe consequences for active fish such as salmonids. Exposure to sublethal pH caused significant reductions in plasma Na+ and Cl− concentrations at both temperatures, although these were more substantial at 5°C than at 15°C. Swimming at Ucrit had no significant effect on plasma concentrations of Na+, K+ and Cl− except at sublethal pH at 5°C, when there were significant reductions in all three. Seasonal temperature had significant but small effects on resting MO2 and Ucrit, and these are discussed in terms of the possible effects of low temperature and continued swimming activity (training) on hypertrophy of skeletal and cardiac muscles and on the aerobic capacity of the ‘red’ muscle fibres.

THE RELATIONSHIP BETWEEN INTRACELLULAR pH AND SEASONAL TEMPERATURE IN THE BROWN TROUT SALMO TRUTTA

1993 ◽  
Vol 177 (1) ◽  
pp. 293-297
Author(s):  
P. J. Butler ◽  
N. Day
Keyword(s):  
Body Temperature ◽  
Intracellular Ph ◽  
Brown Trout ◽  
Salmo Trutta ◽  
Seasonal Temperature ◽  
Temperature Changes ◽  
Neutral Ph ◽  
Brown Trout Salmo Trutta ◽  
The Relationship

Early studies on reptiles demonstrated that plasma pH increases as body temperature falls (Robin, 1962). Rahn (1967) proposed that plasma pH in all poikilothermic vertebrates is regulated as body temperature changes so as to maintain a constant relative alkalinity, i.e. a constant [OH-]/[H+] ratio, and Reeves (1972) suggested a way in which this could be achieved. Known as the ‘imidazole alphastat hypothesis’, it postulates that PCO2 is regulated (by way of ventilation) so that the fractional dissociation (alpha) of the imidazole moiety of histidine is kept constant. As the pK' of imidazole changes with temperature in about the same manner as the neutral pH of water (Heisler, 1986), the alphastat hypothesis is consistent with that of constant relative alkalinity.

THE EFFECT OF EXERCISE ON THE CARDIAC OUTPUT AND BLOOD FLOW DISTRIBUTION OF THE LARGESCALE SUCKER CATOSTOMUS MACROCHEILUS

1993 ◽  
Vol 183 (1) ◽  
pp. 301-321 ◽  
Author(s):  
A. S. Kolok ◽  
M. R. Spooner ◽  
A. P. Farrell
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Swimming Performance ◽  
Flow Distribution ◽  
Fold Increase ◽  
Blood Flow Distribution ◽  
Dramatic Decline ◽  
Red Muscle ◽  
Catostomus Macrocheilus ◽  
A Current

Cardiac output (Q.) and blood flow distribution were measured in adult largescale suckers at rest and while swimming. Cardiac output was directly measured using an ultrasonic flowprobe in fish during the summer (16°C), fall (10°C) and winter (5°C). Largescale suckers were adept at holding station against a current without swimming and, when engaged in this behavior, they did not significantly increase Q. relative to that found in fish in still water. When fish began to swim, Q. increased significantly. From 16 to 10°C, the critical swimming speed (Ucrit), maximum Q. and scope for Q. of the suckers did not change. However, from 10 to 5°C all three traits were significantly reduced. Thus, these fish respond to variation in water temperature in two different ways. From 16 to 10°C, the fish compensate perfectly for the change in temperature with respect to cardiac and swimming performance. From 10 to 5°C, however, largescale suckers experience a dramatic decline in cardiac and swimming performance that may be associated with a quiescent overwintering strategy. Blood flow distribution in the fish at rest and while swimming was measured at 16°C using injection of colored microspheres. In the resting fish, over 10 % of the microspheres were recovered from the kidney and over 43 % were recovered from white muscle. When the fish were swimming, there was a 60-fold increase in blood flow to the red muscle while blood flow to all other tissues remained consistent with that at rest.

Breaking the speed limit — comparative sprinting performance of brook trout (Salvelinus fontinalis) and brown trout (Salmo trutta)

2013 ◽  
Vol 70 (2) ◽  
pp. 280-293 ◽  
Author(s):  
Theodore Castro-Santos ◽  
Francisco Javier Sanz-Ronda ◽  
Jorge Ruiz-Legazpi
Keyword(s):  
Brown Trout ◽  
Brook Trout ◽  
Salmo Trutta ◽  
Salvelinus Fontinalis ◽  
Swimming Performance ◽  
Physiological Limits ◽  
Brown Trout Salmo Trutta ◽  
Free Ranging ◽  
The Relationship ◽  
Sprint Swimming

Sprinting behavior of free-ranging fish has long been thought to exceed that of captive fish. Here we present data from wild-caught brook trout (Salvelinus fontinalis) and brown trout (Salmo trutta), volitionally entering and sprinting against high-velocity flows in an open-channel flume. Performance of the two species was nearly identical, with the species attaining absolute speeds > 25 body lengths·s−1. These speeds far exceed previously published observations for any salmonid species and contribute to the mounting evidence that commonly accepted estimates of swimming performance are low. Brook trout demonstrated two distinct modes in the relationship between swim speed and fatigue time, similar to the shift from prolonged to sprint mode described by other authors, but in this case occurring at speeds > 19 body lengths·s−1. This is the first demonstration of multiple modes of sprint swimming at such high swim speeds. Neither species optimized for distance maximization, however, indicating that physiological limits alone are poor predictors of swimming performance. By combining distributions of volitional swim speeds with endurance, we were able to account for >80% of the variation in distance traversed by both species.

Disease and Civilization: A Scottish Atlantic Network of Physicians in the Enlightenment

2017 ◽  
Vol 10 (2) ◽  
pp. 197-216
Author(s):  
Sarah Irving-Stonebraker
Keyword(s):  
Nineteenth Century ◽  
Native Americans ◽  
Early Nineteenth Century ◽  
The Enlightenment ◽  
Historical Progress ◽  
Practice Of Medicine ◽  
Benjamin Rush ◽  
American Physician ◽  
The Relationship ◽  
A Current

Through an examination of the extensive papers, manuscripts and correspondence of American physician Benjamin Rush and his friends, this article argues that it is possible to map a network of Scottish-trained physicians in the late eighteenth and early nineteenth-century Atlantic world. These physicians, whose members included Benjamin Rush, John Redman, John Morgan, Adam Kuhn, and others, not only brought the Edinburgh model for medical pedagogy across the Atlantic, but also disseminated Scottish stadial theories of development, which they applied to their study of the natural history and medical practices of Native Americans and slaves. In doing so, these physicians developed theories about the relationship between civilization, historical progress and the practice of medicine. Exploring this network deepens our understanding of the transnational intellectual geography of the eighteenth and early nineteenth century British World. This article develops, in relation to Scotland, a current strand of scholarship that maps the colonial and global contexts of Enlightenment thought.

scholarly journals The interaction between two trains of impulses converging on the same motoneurone

1929 ◽  
Vol 105 (738) ◽  
pp. 363-371 ◽  
Keyword(s):  
Mechanical Effect ◽  
The Other ◽  
Muscle Fibres ◽  
Flexor Muscle ◽  
Afferent Pathways ◽  
Afferent Nerves ◽  
Maximal Stimulation ◽  
The Common ◽  
The Relationship ◽  
Stimulation Of

It was shown in an earlier paper (7) that if maximal stimulation of either of two different afferent nerves can reflexly excite fractions of a given flexor muscle, there are generally, within the aggregate of neurones which innervate that muscle, motoneurones which can be caused to discharge by either afferent (i. e., motoneurones common to both fractions). The relationship which two such afferents bear to a common motoneurone was shown, by the isometric method of recording contraction, to be such that the activation of one afferent, at a speed sufficient to cause a maximal motor tetanus when trans­mitted to the muscle fibres, caused exclusion of any added mechanical effect when the other afferent was excited concurrently. This default in mechanical effect was called “occlusion.” Occlusion may conceivably be due to total exclusion of the effect of one afferent pathway on the common motoneurone by the activity of the other; but facilitation of the effect of one path by the activation of the other when the stimuli were minimal suggests that, in some circumstances at least, the effect of each could augment and summate with th at of the other at the place of convergence of two afferent pathways. Further investigation, using the action currents of the muscle as indication of the nerve impulses discharged by the motoneurone units, has now given some information regarding the effect of impulses arriving at the locus of convergence by one afferent path when the unit common to both is already discharging in response to impulses arriving by the other afferent path. Our method has been to excite both afferent nerves in overlapping sequence by series of break shocks at a rapid rate and to examine the action currents of the resulting reflex for evidence of the appearance of the rhythm of the second series in the discharge caused by the first when the two series are both reaching the motoneurone.

The Relationship between Intracellular pH and Heat Sensitivity in a Thermoresistant Cell Line

1996 ◽  
Vol 145 (2) ◽  
pp. 144 ◽  
Author(s):  
F-F. Liu ◽  
M. D. Sherar ◽  
R. P. Hill
Keyword(s):  
Cell Line ◽  
Intracellular Ph ◽  
Heat Sensitivity ◽  
The Relationship

The resting membrane potential of white muscle from brown trout (Salmo trutta) exposed to copper in soft, acidic water

2000 ◽  
Vol 203 (14) ◽  
pp. 2229-2236 ◽  
Author(s):  
M.W. Beaumont ◽  
E.W. Taylor ◽  
P.J. Butler
Keyword(s):  
Membrane Potential ◽  
Brown Trout ◽  
Salmo Trutta ◽  
White Muscle ◽  
Low Ph ◽  
Ammonium Ion ◽  
Muscle Membrane ◽  
Resting Membrane Potential ◽  
Muscle Fibres ◽  
Brown Trout Salmo Trutta

Previously, the distribution of ammonia between the intracellular and extracellular compartments has been used to predict a significant depolarisation of the resting membrane potential (E(M)) of white muscle from brown trout (Salmo trutta) exposed to a sub-lethal combination of copper and low pH. However, this prediction is based upon two assumptions (i) a relatively high membrane permeability for the ammonium ion with respect to that for ammonia gas and (ii) that this is unaltered by exposure to copper and low pH. Since there is conflicting evidence in the literature of the validity of these assumptions, in the present study E(M) was directly measured in white muscle fibres of trout exposed to copper and low pH (E(M)=−52.2+/−4.9 mV) and compared with that of unexposed, control animals (E(M)=−86.5+/−2.9 mV) (means +/− s.e.m., N=6). In confirming the predicted depolarisation, these data support the hypothesis of electrophysiological impairment as a factor in the reduction in the swimming performance of trout exposed to these pollutants. In addition, the results of this study support the role of a significant permeability of the muscle membrane to NH(4)(+) in determining the distribution of ammonia in fish.

Swimming performance of brown trout and grayling show species‐specific responses to changes in temperature

2018 ◽  
Vol 28 (2) ◽  
pp. 241-246
Author(s):  
Annette Taugbøl ◽  
Kjetil Olstad ◽  
Kim Magnus Bærum ◽  
Jon Museth
Keyword(s):  
Brown Trout ◽  
Swimming Performance ◽  
Species Specific

Effect of systemic acid-base disorders on ileal intracellular pH and ion transport

1986 ◽  
Vol 250 (5) ◽  
pp. G588-G593 ◽  
Author(s):  
J. D. Wagner ◽  
P. Kurtin ◽  
A. N. Charney
Keyword(s):  
Intracellular Ph ◽  
Respiratory Acidosis ◽  
Strong Correlations ◽  
Sprague Dawley ◽  
Acid Base ◽  
Ileal Mucosa ◽  
Arterial Pco2 ◽  
Co2 Partial Pressure ◽  
Arterial Ph ◽  
Acute Metabolic Acidosis

We previously reported that changes in ileal net Na absorption correlated with arterial pH, changes in net HCO3 secretion correlated with the plasma HCO3 concentration, and changes in net Cl absorption correlated with arterial CO2 partial pressure (PCO2) during the systemic acid-base disorders. To determine whether changes in intracellular pH (pHi) and HCO3 concentration [( HCO3]i) mediated these effects, we measured pHi and calculated [HCO3]i in the distal ileal mucosa of anesthetized, mechanically ventilated Sprague-Dawley rats using 5,5-[14C]dimethyloxazolidine-2,4,-dione and [3H]inulin. Rats were studied during normocapnia, acute respiratory acidosis, and alkalosis, and uncompensated and pH-compensated acute metabolic acidosis and alkalosis. When animals in all groups were considered, mucosal pHi was not altered, but there were strong correlations between mucosal [HCO3]i and both arterial PCO2 (r = 0.97) and [HCO3] (r = 0.61). When we considered the rates of ileal electrolyte transport that characterized these acid-base disorders [A. N. Charney and L.P. Haskell, Am. J. Physiol. 245 (Gastrointest. Liver Physiol. 8): G230-G235, 1983], we found strong correlations between mucosal [HCO3]i and both net Cl absorption (r = 0.88) and net HCO3 secretion (r = 0.82). These findings suggest that the systemic acid-base disorders do not affect ileal mucosal pHi but do alter mucosal [HCO3]i as a consequence of altered arterial PCO2 and [HCO3]. The effects of these disorders on ileal net Cl absorption and HCO3 secretion may be mediated by changes in [HCO3]i. Arterial pH does not appear to alter ileal Na absorption through changes in the mucosal acid-base milieu.

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