scholarly journals It takes time to heal a broken heart: Ventricular plasticity improves heart performance after myocardial infarction in rainbow trout, Oncorhynchus mykiss

2021 ◽  
Author(s):  
Lucas A. Zena ◽  
Andreas Ekström ◽  
Albin Gräns ◽  
Catharina Olsson ◽  
Michael Axelsson ◽  
...  
Keyword(s):  
Heart Rate ◽  
Rainbow Trout ◽  
Coronary Artery ◽  
Oncorhynchus Mykiss ◽  
Coronary Occlusion ◽  
Morphological Characteristics ◽  
Coronary Artery Ligation ◽  
Resting Heart Rate ◽  
Rainbow Trout Oncorhynchus Mykiss

Coronary arteriosclerosis is a common feature of both wild and farmed salmonid fishes and may be linked to stress-induced cardiac pathologies. Yet, the plasticity and capacity for long-term myocardial restructuring and recovery following a restriction in coronary blood supply is unknown. Here, we analyzed the consequences of acute (3 days) and chronic (from 33 to 62 days) coronary occlusion (i.e., coronary artery ligation) on cardiac morphological characteristics and in vivo function in juvenile rainbow trout, Oncorhynchus mykiss. Acute coronary occlusion resulted in elevated resting heart rate and decreased inter-beat variability, which are both markers of autonomic dysfunction following acute myocardial ischemia, along with severely reduced heart rate scope (maximum – resting heart rate) relative to sham-operated trout. We also observed a loss of myocardial interstitial collagen and compact myocardium. Following long-term coronary- ligation, resting heart rate and heart rate scope normalized relative to sham-operated trout. Moreover, a distinct fibrous collagen layer separating the compact myocardium into two layers had formed. This may contribute to maintain ventricular integrity across the cardiac cycle, or alternatively, demark a region of the compact myocardium that continues to receive oxygen from the luminal venous blood. Taken together, we demonstrate that rainbow trout may cope with the aversive effects caused by coronary artery obstruction through plastic ventricular remodeling, which, at least in part, restores cardiac performance and myocardium oxygenation.

scholarly journals Long-term exposure to low 17α-ethinylestradiol (EE2) concentrations disrupts both the reproductive and the immune system of juvenile rainbow trout, Oncorhynchus mykiss

2020 ◽  
Vol 142 ◽  
pp. 105836
Author(s):  
Kristina Rehberger ◽  
Elena Wernicke von Siebenthal ◽  
Christyn Bailey ◽  
Patrick Bregy ◽  
Melanie Fasel ◽  
...  
Keyword(s):  
Immune System ◽  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Juvenile Rainbow Trout ◽  
Rainbow Trout Oncorhynchus Mykiss

Long-term primary culture of epithelial cells from rainbow trout (Oncorhynchus mykiss) liver

1995 ◽  
Vol 31 (5) ◽  
pp. 367-378 ◽  
Author(s):  
Gary K. Ostrander ◽  
James B. Blair ◽  
Beverly A. Stark ◽  
Garry M. Marley ◽  
Wesley D. Bales ◽  
...  
Keyword(s):  
Rainbow Trout ◽  
Epithelial Cells ◽  
Oncorhynchus Mykiss ◽  
Primary Culture ◽  
Rainbow Trout Oncorhynchus Mykiss

scholarly journals Long-term prognostic value of resting heart rate in patients with suspected or proven coronary artery disease

2005 ◽  
Vol 26 (10) ◽  
pp. 967-974 ◽  
Author(s):  
Ariel Diaz ◽  
Martial G. Bourassa ◽  
Marie-Claude Guertin ◽  
Jean-Claude Tardif
Keyword(s):  
Coronary Artery Disease ◽  
Heart Rate ◽  
Coronary Artery ◽  
Prognostic Value ◽  
Resting Heart Rate ◽  
Artery Disease

How the efficiency of rainbow trout (Oncorhynchus mykiss) ventricular muscle changes with cycle frequency

2002 ◽  
Vol 205 (5) ◽  
pp. 697-706 ◽  
Author(s):  
Claire L. Harwood ◽  
Iain S. Young ◽  
John D. Altringham
Keyword(s):  
Heart Rate ◽  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Cardiac Muscle ◽  
Power Output ◽  
Energy Cost ◽  
Total Efficiency ◽  
Ventricular Muscle ◽  
Cycle Frequency ◽  
Rainbow Trout Oncorhynchus Mykiss

SUMMARYDifferent species of animals require different cardiac performance and, in turn, their cardiac muscle exhibits different properties. A comparative approach can reveal a great deal about the mechanisms underlying myocardial contraction. Differences in myocardial Ca2+ handling between fish and mammals suggest a greater energy cost of activation in fish. Further, while there is considerable evidence that heart rate (or cycle frequency) should have a profound effect on the efficiency of teleost cardiac muscle, this effect has been largely overlooked. We set out to determine how cycle frequency affects the power output and efficiency of rainbow trout (Oncorhynchus mykiss) ventricular muscle and to relate this to the heart’s function in life. We measured power output and the rate of oxygen consumption (V̇O2) and then calculated efficiency over a physiologically realistic range of cycle frequencies.In contrast to mammalian cardiac muscle, in which V̇O2 increases with increasing heart rate, we found no significant change in V̇O2 in the teleost. However, power output increased by 25 % as cycle frequency was increased from 0.6 to 1.0 Hz, so net and total efficiency increased. A maximum total efficiency of 20 % was achieved at 0.8 Hz, whereas maximum power output occurred at 1.0 Hz. We propose that, since the heart operates continuously, high mechanical efficiency is a major adaptive advantage, particularly at lower heart rates corresponding to the more commonly used slower, sustainable swimming speeds. Efficiency was lower at the higher heart rates required during very fast swimming, which are used during escape or prey capture.If a fixed amount of Ca2+ is released and then resequestered each time the muscle is activated, the activation cost should increase with frequency. We had anticipated that this would have a large effect on the total energy cost of contraction. However, since V̇O2 remains constant, less oxygen is consumed per cycle at high frequencies. We suggest that a constant V̇O2 would be observed if the amount of activator Ca2+ were to decrease with frequency. This decrease in activation energy is consistent with the decrease in the systolic intracellular Ca2+ ([Ca2+]i) transient with increasing stimulation frequency seen in earlier studies.

scholarly journals Importance of the coronary circulation for cardiac and metabolic performance in rainbow trout ( Oncorhynchus mykiss )

2018 ◽  
Vol 14 (7) ◽  
pp. 20180063 ◽  
Author(s):  
Andreas Ekström ◽  
Michael Axelsson ◽  
Albin Gräns ◽  
Jeroen Brijs ◽  
Erik Sandblom
Keyword(s):  
Heart Rate ◽  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Metabolic Rate ◽  
Oxygen Supply ◽  
Coronary Artery Ligation ◽  
Artery Ligation ◽  
Coronary Ligation ◽  
Metabolic Performance

Cardiac oxygenation is achieved via both coronary arterial and luminal venous oxygen supply routes in many fish species. However, the relative importance of these supplies for cardiac and aerobic metabolic performance is not fully understood. Here, we investigated how coronary artery ligation in rainbow trout ( Oncorhynchus mykiss ), implanted with heart rate loggers, affected cardiorespiratory performance in vivo . While coronary ligation significantly elevated resting heart rate, the standard metabolic rate was unchanged compared to sham-treated controls. However, coronary ligation reduced the maximum metabolic rate while heart rate remained unchanged following enforced exercise. Thus, coronary ligation reduced metabolic and heart rate scopes by 29% and 74%, respectively. Our findings highlight the importance of coronary oxygen supply for overall cardiorespiratory performance in salmonid fish, and suggest that pathological conditions that impair coronary flow (e.g. coronary arteriosclerosis) constrain the ability of fish to cope with metabolically demanding challenges such as spawning migrations and environmental warming.

Branchial Morphological and Endocrine Responses of Rainbow Trout (Oncorhynchus mykiss) to a Long-Term Sublethal Acid Exposure In Which Acclimation Did Not Occur

1993 ◽  
Vol 50 (1) ◽  
pp. 198-209 ◽  
Author(s):  
Céline Audet ◽  
Chris M. Wood
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Chloride Cell ◽  
Chloride Cells ◽  
Physiological Data ◽  
Mucous Cells ◽  
Diffusion Distance ◽  
Cell Numbers ◽  
Rainbow Trout Oncorhynchus Mykiss

Changes in branchial morphology and in plasma Cortisol, adrenaline, and noradrenaline were quantified throughout an 81 -d exposure of rainbow trout (Oncorhynchus mykiss) to sublethal acidity (pH 4.8) in artificial soft water and after a 5-h acid challenge (pH 4.0) of naive fish and 81-d acid-preexposed fish. Changes in branchial morphology at pH 4.8 were generally very mild and characterized by slight increases in filamental mucous cells and decreases in lamellar mucous cells. Chloride cell numbers and branchial Na+–K+- and total ATPase activities did not change. The filamental epithelium thickened, but the water–blood diffusion distance in the lamellae decreased during chronic exposure. Cortisol was significantly elevated throughout whereas catecholamines exhibited relatively little response. Response to acute pH 4.0 challenge was similar in naive and 81-d acid-exposed fish: epithelial damage, increase in visible mucous cells, loss of chloride cells by necrosis, and high cortisol levels but no changes in lamellar or filamental epithelial thickness, diffusion distance, ATPase activities, or catecholamine levels. Previously reported physiological data from these same trout demonstrated that sensitization rather than acclimation had occurred. Therefore, these observations support the view that acclimation does not occur in the absence of significant branchial damage and repair.

Vascular reactivity of the coronary artery in rainbow trout (Oncorhynchus mykiss)

1990 ◽  
Vol 258 (6) ◽  
pp. R1402-R1410 ◽  
Author(s):  
S. A. Small ◽  
C. MacDonald ◽  
A. P. Farrell
Keyword(s):  
Rainbow Trout ◽  
Coronary Artery ◽  
Oncorhynchus Mykiss ◽  
Coronary Arteries ◽  
Vascular Reactivity ◽  
Isometric Force ◽  
Lower Vertebrate ◽  
Pharmacological Agents ◽  
Vascular Rings ◽  
Rainbow Trout Oncorhynchus Mykiss

Vascular reactivity of the large coronary artery of a lower vertebrate was investigated for the first time in this study. The responses of vascular rings to various pharmacological agents were measured using isometric force transducers. Coronary arteries from rainbow trout, Oncorhynchus mykiss, contracted with acetylcholine and predominantly relaxed with isoproterenol, epinephrine, norepinephrine, and serotonin. Atenolol blocked the adrenergic relaxation, suggesting a predominance of beta 1-adrenoceptors. Nitroglycerin and sodium nitroprusside relaxed vascular rings. Responses to histamine and bradykinin were absent in this tissue. Adenosine, ADP, and ATP caused contractions that could be blocked by theophylline. The difference in vascular reactivity between that typically found in mammalian coronary arteries and that reported here for rainbow trout are discussed.

Sign in / Sign up

Export Citation Format

Share Document