scholarly journals The Seasonal Intrinsic Cardiac Performance of a Marine Teleost

1985 ◽  
Vol 118 (1) ◽  
pp. 173-183 ◽  
Author(s):  
MARK GRAHAM ◽  
ANTHONY FARRELL
Keyword(s):  
Heart Function ◽  
Cardiac Performance ◽  
Temperature Decrease ◽  
Marine Teleost ◽  
Inotropic Effects ◽  
Sea Raven ◽  
Input Pressure ◽  
Heart Preparation ◽  
Hemitripterus Americanus

1. An in situ heart preparation was used to evaluate cardiac performance in the sea raven, Hemitripterus americanus, under physiological inflow and outflow pressure conditions. Winter and summer fish were subjected to an acute 10°C temperature change from the seasonal ambient value. The maximum cardiac output (V·b) under each temperature condition was determined by altering inflow pressure to the heart. 2. Acute temperature increase produced positive chronotropic and inotropic effects in winter fish. Acute temperature decrease produced a negative chronotropic and inotropic effect in summer fish. 3. The inotropic and chronotropic states of the heart were different in winter and summer fish. Intrinsic heart rate was higher in summer fish at all experimental temperatures. The sensitivity of the summer fish hearts to input pressure was also greater, especially during the warm experimental temperatures. 4. It was evident from heartbeat rate measurements and power output calculations that the advent of summer and winter seasons did not promote any compensatory ability in intrinsic heart function.

Function of myoglobin in oxygen consumption by isolated perfused fish hearts

1986 ◽  
Vol 251 (6) ◽  
pp. R1144-R1150 ◽  
Author(s):  
J. R. Bailey ◽  
W. R. Driedzic
Keyword(s):  
Oxygen Consumption ◽  
Partial Pressure ◽  
Binding Protein ◽  
Protective Role ◽  
Cardiac Performance ◽  
O2 Consumption ◽  
Hypoxic Conditions ◽  
Sea Raven ◽  
Hemitripterus Americanus ◽  
O2 Binding

Myoglobin, an intracellular O2-binding protein, plays a protective role in maintaining performance of isolated fish hearts under hypoxic conditions. This study was designed to test the hypothesis that the protein contributes to O2 consumption under conditions of increased O2 demand or hypoxia. Isolated myoglobin-rich sea raven (Hemitripterus americanus) hearts and myoglobin-poor ocean pout (Macrozoarces americanus) hearts were perfused under conditions of changing partial pressure of O2 (PO2) and afterload. Sea raven hearts maintained O2 consumption and cardiac performance at low PO2 and high afterload, whereas ocean pout hearts did not. In other cases sea raven and ocean pout hearts were treated with hydroxylamine, which renders myoglobin incapable of binding O2, and subjected to changing PO2 and afterload. Sea raven hearts could not maintain O2 consumption and cardiac performance, whereas hydroxylamine treatment had no effect on O2 consumption in ocean pout hearts under these conditions. These data provide the first evidence to support the concept that myoglobin plays a role in O2 consumption of hearts.

scholarly journals Sexual Maturity Can Double Heart Mass and Cardiac Power Output in Male Rainbow Trout

1992 ◽  
Vol 171 (1) ◽  
pp. 139-148 ◽  
Author(s):  
CRAIG E. FRANKLIN ◽  
PETER S. DAVIE
Keyword(s):  
Rainbow Trout ◽  
Body Mass ◽  
Power Output ◽  
Cardiac Performance ◽  
Mature Male ◽  
Perfused Heart ◽  
Cardiac Power ◽  
Heart Preparation ◽  
Ovary Growth

Mature male rainbow trout have significantly higher relative ventricle masses (RVM, ventricle mass as a percentage of body mass) than do immature males or females. Hatchery-reared maturing male trout had a mean RVM of 0.139%, whereas females had an RVM of only 0.074 %. Moreover, as males matured and their testes grew from 0.07 to 3.92 % of body mass, RVM more than doubled. In female trout no such heart growth occurred; RVM remained unchanged during the period of ovary growth. Cardiac performance was assessed using an in situ perfused heart preparation. Mature male trout have larger ventricles and could generate significantly greater maximum cardiac power output per kilogram body mass than could immature males or females. This enhanced cardiac performance by the mature males was attributable to delivery of greater cardiac outputs (through larger stroke volumes) and an increased ability of the heart to work against higher output pressures. Power output per gram ventricle mass was similar in both sexes. Note: Present address: Department of Zoology, University of Queensland, Brisbane 4072, Australia.

scholarly journals Cardiac performance in the in situ perfused fish heart during extracellular acidosis: interactive effects of adrenaline

1983 ◽  
Vol 107 (1) ◽  
pp. 415-429 ◽  
Author(s):  
A. P. Farrell ◽  
K. R. MacLeod ◽  
W. R. Driedzic ◽  
S. Wood
Keyword(s):  
Stroke Volume ◽  
Cardiac Performance ◽  
Interactive Effects ◽  
Perfused Heart ◽  
Fish Heart ◽  
Extracellular Acidosis ◽  
Sea Raven ◽  
Filling Time ◽  
Inotropic Responses

The physiological integrity of the in situ perfused heart of the ocean pout was established by its ability to maintain cardiac output (Q) over a range of work loads, and by the dependence of Q upon the filling pressure of the heart. Similar observations have been reported previously for the in situ perfused heart of the sea raven. Physiological levels of extracellular acidosis (pH 7.6/1% CO2 and pH 7.4/2% CO2) significantly depressed cardiac performance in sea raven and ocean pout hearts in situ. Negative chronotropic and inotropic responses were observed. Adrenaline (AD; 10(−7) M) under control conditions (pH 7.9/0.5% CO2) produced a sustained tachycardia. The tachycardia reduced filling time of the ventricle and stroke volume was compromised because of the constant preload to the heart. Consequently, AD produced only an initial, transient increase in stroke volume and Q. Thereafter, stroke volume was reduced in proportion with the increase in heart rate, and Q remained unchanged. The combined challenge of extracellular acidosis and AD demonstrated interactive effects between AD and acidosis in situ. Q and power output were maintained in both species at both levels of extracellular acidosis during the combined challenge. Thus AD alone can maintain (but not improve upon) basal Q during extracellular acidosis. The effects of extracellular acidosis, circulating catecholamines and venous return pressure to the heart are discussed in relation to the regulation of Q following exhaustive exercise.

IDENTIFICATION AND METABOLIC CLEARANCE OF CORTISOL AND CORTISONE IN A MARINE TELEOST, THE SEA RAVEN HEMITRIPTERUS AMERICANUS GMELIN (FAMILY SCORPAENIDAE)

1972 ◽  
Vol 53 (1) ◽  
pp. 101-112 ◽  
Author(s):  
W. H. OWEN ◽  
D. R. IDLER
Keyword(s):  
Acetic Anhydride ◽  
Metabolic Clearance ◽  
Plasma Samples ◽  
Marine Teleost ◽  
Sea Raven ◽  
Three Samples ◽  
The Mean ◽  
Hemitripterus Americanus ◽  
Percentage Conversion ◽  
Double Isotope

SUMMARY Cortisol and cortisone were identified and their levels determined in sea raven plasma by a double isotope derivative assay involving acetylation with [1-3H]acetic anhydride, purification by thin-layer and paper chromatography, followed by recrystallization to constant 3H: 14C ratios. The mean level of cortisol in four plasma samples was 7·2±1·0 μg/100 ml (range 4·0–9·2) and the mean level for cortisone in three samples was 1·1 ± 0·2 μg/100 ml (range 0·7–1·5). Metabolic clearance rates (MCR) were determined for both corticosteroids by the method of continuous infusion over an 8-h period. The mean MCR for cortisol in five fish was 126 ± 17 ml/kg/h, and for cortisone 449 ± 48 ml/kg/h in six fish. The mean percentage conversion of [1,2-3H]cortisol to cortisone was 9·4 ± 2·9%. There was no evidence of any significant conversion of cortisone to cortisol.

scholarly journals Maximum cardiac performance of Antarctic fishes that lack haemoglobin and myoglobin: exploring the effect of warming on nature’s natural knockouts

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Stuart Egginton ◽  
Michael Axelsson ◽  
Elizabeth L Crockett ◽  
Kristin M O’Brien ◽  
Anthony P Farrell
Keyword(s):  
Selective Advantage ◽  
Cardiac Performance ◽  
Polar Regions ◽  
Perfused Heart ◽  
Antarctic Species ◽  
Antarctic Notothenioids ◽  
Notothenia Coriiceps ◽  
Heart Preparation

Abstract Antarctic notothenioids, some of which lack myoglobin (Mb) and/or haemoglobin (Hb), are considered extremely stenothermal, which raises conservation concerns since Polar regions are warming at unprecedented rates. Without reliable estimates of maximum cardiac output ($\dot{Q}$), it is impossible to assess their physiological scope in response to warming seas. Therefore, we compared cardiac performance of two icefish species, Chionodraco rastrospinosus (Hb−Mb+) and Chaenocephalus aceratus (Hb−Mb−), with a related notothenioid, Notothenia coriiceps (Hb+Mb+) using an in situ perfused heart preparation. The maximum $\dot{Q}$, heart rate (fH), maximum cardiac work (WC) and relative ventricular mass of N. coriiceps at 1°C were comparable to temperate-water teleosts, and acute warming to 4°C increased fH and WC, as expected. In contrast, icefish hearts accommodated a higher maximum stroke volume (VS) and maximum $\dot{Q}$ at 1°C, but their unusually large hearts had a lower fH and maximum afterload tolerance than N. coriiceps at 1°C. Furthermore, maximum VS, maximum $\dot{Q}$ and fH were all significantly higher for the Hb−Mb+ condition compared with the Hb−Mb− condition, a potential selective advantage when coping with environmental warming. Like N. coriiceps, both icefish species increased fH at 4°C. Acutely warming C. aceratus increased maximum $\dot{Q}$, while C. rastrospinosus (like N. coriiceps) held at 4°C for 1 week maintained maximum $\dot{Q}$ when tested at 4°C. These experiments involving short-term warming should be followed up with long-term acclimation studies, since the maximum cardiac performance of these three Antarctic species studied seem to be tolerant of temperatures in excess of predictions associated with global warming.

scholarly journals Lactate Utilization by an In Situ Perfused Trout Heart: Effects of Workload and Blockers of Lactate Transport

1991 ◽  
Vol 155 (1) ◽  
pp. 357-373 ◽  
Author(s):  
C. LOUISE MILLIGAN ◽  
ANTHONY P. FARRELL
Keyword(s):  
Iodoacetic Acid ◽  
Cardiac Performance ◽  
Lactate Transport ◽  
Lactate Oxidation ◽  
High Workload ◽  
Heart Preparation ◽  
Disulphonic Acid ◽  
Lactate Utilization

Lactate utilization was studied in an in situ perfused trout heart preparation that was capable of performing at levels similar to in vivo maximum cardiac performance. Hearts were perfused with modified Cortland saline containing 0.5 mmol l−1 iodoacetic acid (to block endogenous glycolysis) and varying amounts of lactate (1 or 10 mmoll−1). We confirmed previous observations that lactate utilization is limited by substrate availability. However, contrary to previous observations, exogenous fuel availability did not limit cardiac performance, even at the high workload. Furthermore, when plentiful (i.e. 10 mmol l−1), exogenous lactate was preferred over endogenous fuel and was able to supply the heart's energy requirements at both the low and high workloads. Pyruvate at 10- fold greater concentration, had no apparent effect on lactate utilization at the high workload. α-Cyano-4-hydroxycinnamate (α-CIN) (2.5 mmoll−1) proved to be an unsuitable probe of lactate transport in the trout heart as it caused a reduction in both lactate utilization and cardiac performance. However, addition of 20 μmol l−1 isobutyl carbonyl lactyl anhydride or 100 μmol l−1 4-acetamido-4′-isothiocyanostilbene-2,2′-disulphonic acid (putative lactate transport blockers) to the perfusate virtually abolished lactate oxidation at the high workload without affecting cardiac performance. These observations suggest that lactate uptake by the in situ perfused trout heart is carrier-mediated.

The effects of preload, after load, and epinephrine on cardiac performance in the sea raven, Hemitripterus americanus

1982 ◽  
Vol 60 (12) ◽  
pp. 3165-3171 ◽  
Author(s):  
A. P. Farrell ◽  
K. MacLeod ◽  
W. R. Driedzic
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Stroke Volume ◽  
Work Load ◽  
Inotropic Effects ◽  
Fourfold Increase ◽  
Intrinsic Factors ◽  
Sea Raven

The preparation of the in situ heart was accomplished without any physical disturbance to the heart. The heart generated an intrinsic rhythm which was steady throughout the experiment and apparently was derived from the sinoatrial pacemaker. The power output developed by the in situ heart at physiological preloads and after loads was comparable to in vivo values. The effect of increasing preload (0 to 3 cmH2O) was a fourfold increase in stroke volume with little or no change in heart rate. When after load was changed (25 to 45 cmH2O) heart rate was unchanged and stroke volume was usually maintained. As a consequence, cardiac output was maintained by intrinsic factors alone at a higher work load. Epinephrine (10−9 to 10−5 M) in the perfusate produced relatively weak positive chronotropic and inotropic effects. The increase in cardiac output produced by epinephrine was small compared with the intrinsic changes evoked when preload was raised.

Hemodynamic Determinants of Coronary Flow: Effect of Changes in Aortic Pressure and Cardiac Output on the Relationship Between Myocardial Oxygen Consumption and Coronary Flow

1957 ◽  
Vol 192 (1) ◽  
pp. 157-163 ◽  
Author(s):  
E. Braunwald ◽  
S. J. Sarnoff ◽  
R. B. Case ◽  
W. N. Stainsby ◽  
G. H. Welch
Keyword(s):  
Cardiac Output ◽  
Coronary Flow ◽  
Aortic Pressure ◽  
Left Ventricular ◽  
Ventricular Filling Pressure ◽  
Heart Preparation ◽  
Ventricular Filling ◽  
The Relationship ◽  
Hemodynamic Determinants

Although the general dependence of coronary flow on myocardial qo2 was confirmed in an in situ heart preparation, changes in aortic pressure and cardiac output were observed to be capable of influencing this relationship. Neither myocardial qo2 nor coronary flow were found to be dependent on left ventricular filling pressure.

Inotropic effects of ejection are myocardial properties

1994 ◽  
Vol 266 (3) ◽  
pp. H1202-H1213 ◽  
Author(s):  
P. P. De Tombe ◽  
W. C. Little
Keyword(s):  
Systolic Pressure ◽  
Left Ventricular ◽  
Negative Effects ◽  
Inotropic Effects ◽  
Contraction Duration ◽  
Loading System ◽  
Positive Effect ◽  
Isolated Rat

Recent studies in isolated and in vivo canine hearts have suggested that the left ventricular end-systolic pressure (LVPes) of ejecting beats is the net result of a balance between positive and negative effects of ejection. At present, it is unknown whether these ejection effects are merely a ventricular chamber property or represent a fundamental myocardial property. Accordingly, we examined the effects of ejection in eight isolated rat cardiac trabeculae at the sarcomere level. We approximated in situ sarcomere shortening patterns using an iterative computer loading system. Six isovolumic contractions were compared with four ejecting contractions. The superfusing solution contained either 0.7 mM Ca2+ or 0.65 mM Sr2+ plus 0.15 mM Ca2+. With Ca2+, simulated LVPes ("LVP"es) of ejecting contractions was significantly lower than isovolumic "LVP"es (-5.3 +/- 5.6%), whereas with Sr2+, ejecting "LVP"es was significantly higher than isovolumic "LVP"es (+4.5 +/- 7.5%). Contraction duration and time to end systole were markedly prolonged in ejecting vs. isovolumic contractions with either Ca2+ or Sr2+. As a consequence, comparison of simulated LVP between ejecting and isovolumic beats throughout the contraction, i.e., at the same simulated LVV and time, revealed only a positive effect of ejection with either Ca2+ (+18.8 +/- 5.5%) or Sr2+ (+23.4 +/-9.3%). We conclude that both positive and negative effects of ejection are basic myocardial properties.

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