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[COMPARATIVE STUDY OF Y³⁺ EFFECT ON CALCIUM-DEPENDENT PROCESSES IN FROG CARDIAC MUSCLE AND IN MITOCHONDRIA OF RAT
Zhurnal Evoliutsionnoi Biokhimii I Fiziologii
|January 30, 2019
Summary
Yttrium (Y³⁺) negatively impacts heart muscle contractions and mitochondrial function. This study reveals Y³⁺ reduces cardiac muscle contractility and alters calcium-dependent processes in rat heart mitochondria.
Area of Science:
- Cardiovascular Physiology
- Mitochondrial Biology
- Biochemistry
Background:
- Yttrium compounds have shown varied biological effects.
- Understanding the impact of rare earth elements on cardiac function is crucial.
- Calcium ions play a vital role in myocardial contraction and mitochondrial energetics.
Purpose of the Study:
- To investigate the inotropic effects of yttrium acetate (Y³⁺) on frog myocardium.
- To examine the influence of Y³⁺ on respiration and inner membrane potential (Δψmito) in isolated rat heart mitochondria.
- To elucidate the mechanisms underlying Y³⁺'s effects on calcium-dependent cardiac processes.
Main Methods:
- Studied isolated frog myocardium preparations (Rana ridibunda) subjected to electrical stimulation.
- Utilized isolated rat heart mitochondria to assess respiration rates and inner membrane potential.
- Employed techniques to measure oxygen consumption and membrane potential changes in response to Y³⁺ and calcium (Ca²⁺).
Main Results:
- Yttrium (Y³⁺) significantly reduced the amplitude of frog myocardium contractions and increased relaxation time.
- Y³⁺ decreased Ca²⁺-dependent oxygen consumption in rat heart mitochondria energized by glutamate and malate.
- Y³⁺ impeded respiratory decline in state 3 and 2,4-dinitrophenol-uncoupled mitochondria, and inhibited Ca²⁺-induced Δψmito decrease.
Conclusions:
- Yttrium (Y³⁺) exhibits a negative inotropic effect on myocardial contractility.
- Y³⁺ interferes with calcium-dependent mitochondrial respiration and membrane potential regulation.
- These findings contribute to understanding the mechanisms of Y³⁺'s impact on cardiac calcium handling.
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