scholarly journals Coronary flow in a perfused rainbow trout heart

1987 ◽  
Vol 129 (1) ◽  
pp. 107-123 ◽  
Author(s):  
A. P. Farrell
Keyword(s):  
Rainbow Trout ◽  
Coronary Flow ◽  
Coronary Circulation ◽  
Coronary Vessels ◽  
Cardiac Metabolism ◽  
Salmo Gairdneri ◽  
Acclimation Temperature ◽  
Coronary Vascular Resistance ◽  
Coronary Resistance ◽  
Temperature Dependent

A preparation was developed to perfuse the coronary circulation in working hearts from rainbow trout (Salmo gairdneri Richardson). The preparation was used to examine pressure-flow relationships for the coronary circulation as the heart generated physiological and subphysiological work loads. Coronary vascular resistance increased exponentially as coronary flow rate decreased. Coronary resistance was also influenced by cardiac metabolism and acclimation temperature. When heart rate was increased, extravascular compression increased in coronary resistance. Direct vasoconstriction of the coronary vessels, produced by injections of adrenaline into the coronary circulation, was temperature-dependent.

Trypsin from Two Strains of Rainbow Trout, Salmo gairdneri, is Influenced Differently by Assay and Acclimation Temperature

1986 ◽  
Vol 43 (8) ◽  
pp. 1664-1667 ◽  
Author(s):  
J. M. McLeese ◽  
E. Don Stevens
Keyword(s):  
Rainbow Trout ◽  
Cold Acclimation ◽  
High Strain ◽  
Specific Activity ◽  
Intestinal Morphology ◽  
Salmo Gairdneri ◽  
Acclimation Temperature ◽  
Nutrient Requirements ◽  
Lower Affinity ◽  
Pyloric Caeca

Specific activity and kinetic constants of trypsin from the pyloric caeca of two strains of rainbow trout, Salmo gairdneri, were measured using α-N-benzoyl-DL-arginine-ρ-nitroaniline∙HCl No increase in activity was observed with cold acclimation, suggesting that cold acclimation induces no increase in trypsin concentration. The apparent Km for the substrate was independent of assay temperature over the physiological range in both strains, probably to maintain high rates of catalysis at higher temperatures when nutrient requirements are high. Strain A trout produced a trypsin with lower affinity on cold acclimation, but Strain B trout did not. The two strains differed in intestinal morphology as well as in the characteristics of their trypsins.

The effect of vasoactive drugs on local coronary flow

1969 ◽  
Vol 47 (5) ◽  
pp. 421-425 ◽  
Author(s):  
Edilberto C. Torres ◽  
Giorgio Brandi
Keyword(s):  
Injection Site ◽  
Coronary Flow ◽  
Coronary Circulation ◽  
Coronary Vessels ◽  
Flow Volume ◽  
Vasoactive Drugs ◽  
Small Vessels ◽  
Receptor Sites ◽  
Xenon 133 ◽  
Selective Effects

A method is described by which it is possible to study the selective effects of vasoactive drugs on the small vessels of the coronary circulation of the dog. We incorporated xenon-133 with different drugs and derived the flow/volume ratios from the rate of fall of radioactivity at the injection site. Ratios were consistently reduced by angiotensin (−37%), pitressin (−40%), and propranolol (−13%), and were increased by dipyridamole (+23%), nitroglycerine (+14%), isoproterenol (+30%), adrenaline (+30%), and noradrenaline (+25%), indicating that these agents have an effect on the small coronary vessels. Ratios were unaltered by phenylephrine and by combinations of propranolol with adrenaline or noradrenaline, suggesting that alpha receptor sites may be absent from the small vessel bed under study.

Na+:K+- and HCO3−-stimulated ATPase activities in the gills and kidneys of thermally acclimated rainbow trout, Salmo gairdneri

1977 ◽  
Vol 55 (4) ◽  
pp. 704-712 ◽  
Author(s):  
L. S. McCarty ◽  
A. H. Houston
Keyword(s):  
Rainbow Trout ◽  
Significant Variation ◽  
Sodium Balance ◽  
Salmo Gairdneri ◽  
Acclimation Temperature ◽  
Sodium Potassium ◽  
Cold Adapted ◽  
Atpase System ◽  
Temperature Amplifier ◽  
Assay Conditions

Gill and kidney Mg2+-dependent, Na+:K+- and HCO3−-stimulated ATPase (EC 3.6.1.3) activities were estimated at 25 °C and at acclimation temperature in rainbow trout, Salmo gairdneri, acclimated to 2, 10, and 18 °C, as were plasma levels of sodium, potassium, and chloride. Sodium and chloride exhibited no significant variation between 2 and 18 °C; potassium levels were elevated at 18 °C. When assayed at 25 °C Mg2+-dependent and HCO3−-stimulated ATPase activities did not vary consistently or significantly in relation to acclimation temperature. Under comparable assay conditions both gill and kidney Na+:K+-stimulated activities declined at higher acclimation temperatures. Significant increases in all activities were encountered when preparations were incubated at the appropriate acclimation temperature. The data suggest that the branchial Na+:K+–ATPase system serves primarily as a high-temperature amplifier of sodium uptake, and may contribute little to the maintenance of sodium balance in the cold-adapted animal. No evidence of a critical involvement of HCO3−-stimulated ATPase in ionic regulations was obtained.

Sealed-Jar Bioassays for Pulpmill Effluent Toxicity: Effects of Fish Species and Temperature

1977 ◽  
Vol 34 (9) ◽  
pp. 1389-1396 ◽  
Author(s):  
Michael R. Gordon ◽  
Donald J. McLeay
Keyword(s):  
Rainbow Trout ◽  
Fish Species ◽  
Test Temperature ◽  
Coho Salmon ◽  
Temperature Acclimation ◽  
Salmo Gairdneri ◽  
Acclimation Temperature ◽  
Specific Response ◽  
Oxygen Utilization ◽  
Effluent Toxicity

To standardize the sealed-jar bioassay for optimum sensitivity to whole bleached kraft pulpmill effluent, experiments were designed to assess the effects of test temperature, acclimation temperature, and fish species. Coho salmon (Oncorhynchus kisutch) conformed to a previously recognized test paradigm by showing progressively decreased oxygen utilization with increasing toxicant concentrations; however, rainbow trout (Salmo gairdneri) did not. In concentrations of effluent < 1.5 LC50, rainbow trout used significantly more oxygen than control groups, while coho salmon used significantly less oxygen. The sensitivity of these responses was influenced by test temperature and acclimation temperature. Results for coho confirmed that this species was most sensitive to effluent when tested at ambient room temperature. Both species showed significantly decreased oxygen utilization in effluent concentrations > 1.5 LC50 irrespective of test temperature or acclimation temperature. The significance of these responses is discussed, and the applicability of sealed-jar bioassays for assessing the acute toxicity of pulpmill effluents is reviewed. Key words: residual oxygen bioassay, sealed-jar bioassay, pulpmill effluent toxicity, temperature, hyperthermia, respiration, hypoxia, species-specific response

Rheological properties of rainbow trout blood

1987 ◽  
Vol 65 (4) ◽  
pp. 879-883 ◽  
Author(s):  
Garth L. Fletcher ◽  
R. Tyson Haedrich
Keyword(s):  
Rainbow Trout ◽  
Shear Rate ◽  
Salvelinus Alpinus ◽  
Salmo Gairdneri ◽  
Pseudopleuronectes Americanus ◽  
Temperature Dependent ◽  
Shear Dependent Viscosity ◽  
Myoxocephalus Scorpius ◽  
Lower Temperature ◽  
Dependent Viscosity

The effects of shear rate and red cell concentration on the viscosity of rainbow trout (Salmo gairdneri) blood were evaluated at 0 and 15 °C using a cone-plate viscometer. The viscosity of blood was shear dependent at both temperatures, with the highest values occurring at the lower temperature and shear rate. The viscosity of plasma was not shear dependent. Viscosity of blood increased in a linear fashion between hematocrits of 0 and 40%. Viscosity of the rainbow trout blood was similar to that of arctic char (Salvelinus alpinus), but considerably lower and less shear and temperature dependent than the bloods of winter flounder (Pseudopleuronectes americanus) and shorthorn sculpin (Myoxocephalus scorpius). It is hypothesized that low shear and temperature dependent blood viscosity may be a characteristic of active fish.

Influence of thermal acclimation on membrane lipid composition of rainbow trout liver

1979 ◽  
Vol 236 (1) ◽  
pp. R91-R101 ◽  
Author(s):  
J. R. Hazel
Keyword(s):  
Fatty Acids ◽  
Rainbow Trout ◽  
Polyunsaturated Fatty Acids ◽  
Cold Acclimation ◽  
Saturated Fatty Acids ◽  
Total Content ◽  
Membrane Lipid ◽  
Salmo Gairdneri ◽  
Acclimation Temperature ◽  
Induced Changes

Rainbow trout (Salmo gairdneri) acclimated to 5 degrees C possessed larger livers and less neutral lipid per gram of liver than 20 degrees C-acclimated animals; quantities of liver glycolipid, phospholipid, and cholesterol did not vary significantly with acclimation temperature. The relative proportions of phosphatidylethanolamine increased significantly following cold exposure, whereas the quantities of sphingomyelin and cardiolipin declined. For all phosphatides examined (phosphatidylethanolamine, phosphatidylcholine, phosphatidylserine, phosphatidylinositol, lysolecithin, cardiolipin, sphingomyelin) cold acclimation resulted in 1) an increase in the quantity of polyunsaturated fatty acids, 2) a reduction in the level of saturated fatty acids, and 3) little change in the total content of monoenes and dienes. The increased content of polyunsaturated fatty acids in choline and ethanolamine phosphatides following cold acclimation was confined to the 2-position and occurred at the expense of monoenes and dienes. The relative proportions of n - 3 fatty acids, and less frequently n - 6 fatty acids, increased in phosphatides of cold-acclimated trout, whereas the relative proportions of n - 9 fatty acids declined. These data suggest a preferential incorporation of fatty acids belonging to the linolenic acid family at reduced temperatures. Temperature-induced changes in the chemical composition of trout liver phospholipids counteracted the effects of acute temperature change on nonelectrolyte permeability of isolated liposomes.

scholarly journals THE INFLUENCE OF EPINEPHRIN UPON THE CORONARY CIRCULATION OF THE MONKEY

1915 ◽  
Vol 21 (4) ◽  
pp. 330-336 ◽  
Author(s):  
Henry G. Barbour ◽  
Alexander L. Prince
Keyword(s):  
Coronary Arteries ◽  
Coronary Flow ◽  
Coronary Circulation ◽  
Coronary Vessels ◽  
Locke Solution

Decrease in coronary flow was the constant response of freshly isolated monkey hearts to epinephrin. These hearts were perfused with autogenous hirudinized blood diluted with Locke solution. The results were constant at high or low perfusion pressures, in beating or resting hearts, and with all adequate doses. Increased coronary flow was obtained constantly in rabbit hearts under identical conditions. In the light of previous work upon isolated human coronary arteries, the general conclusion is drawn that, while actively dilating the coronary vessels in the dog, cat, rabbit, ox, sheep, and pig, epinephrin constricts the coronary vessels in man and the monkey. The coronary arteries of the last two species are presumably supplied with constrictor nerves of true sympathetic (thoracicolumbar) origin.

scholarly journals Influence of the coronary circulation on thermal tolerance and cardiac performance during warming in rainbow trout

2017 ◽  
Vol 312 (4) ◽  
pp. R549-R558 ◽  
Author(s):  
Andreas Ekström ◽  
Michael Axelsson ◽  
Albin Gräns ◽  
Jeroen Brijs ◽  
Erik Sandblom
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Rainbow Trout ◽  
Cardiac Function ◽  
Thermal Tolerance ◽  
Coronary Flow ◽  
Coronary Circulation ◽  
Cardiac Performance ◽  
Juvenile Trout

Thermal tolerance in fish may be related to an oxygen limitation of cardiac function. While the hearts of some fish species receive oxygenated blood via a coronary circulation, the influence of this oxygen supply on thermal tolerance and cardiac performance during warming remain unexplored. Here, we analyzed the effect in vivo of acute warming on coronary blood flow in adult sexually mature rainbow trout ( Onchorhynchus mykiss) and the consequences of chronic coronary ligation on cardiac function and thermal tolerance in juvenile trout. Coronary blood flow at 10°C was higher in females than males (0.56 ± 0.08 vs. 0.30 ± 0.08 ml·min−1·g ventricle−1), and averaged 0.47 ± 0.07 ml·min−1·g ventricle−1 across sexes. Warming increased coronary flow in both sexes until 14°C, at which it peaked and plateaued at 0.78 ± 0.1 and 0.61 ± 0.1 ml·min−1·g ventricle−1 in females and males, respectively. Thus, the scope for increasing coronary flow was 101% in males, but only 39% in females. Coronary-ligated juvenile trout exhibited elevated heart rate across temperatures, reduced Arrhenius breakpoint temperature for heart rate (23.0 vs. 24.6°C), and reduced upper critical thermal maximum (25.3 vs. 26.3°C). To further analyze the effects of coronary flow restriction on cardiac rhythmicity, electrocardiogram characteristics were determined before and after coronary occlusion in anesthetized trout. Occlusion resulted in reduced R-wave amplitude and an elevated S-T segment, indicating myocardial ischemia, while heart rate was unaffected. This suggests that the tachycardia in ligated trout across temperatures in vivo was mainly to compensate for reduced cardiac contractility to maintain cardiac output. Moreover, our findings show that coronary flow increases with warming in a sex-specific manner. This may improve whole animal thermal tolerance, presumably by sustaining cardiac oxygenation and contractility at high temperatures.

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