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Cardiovascular effects of BRX-005 comparison to bimoclomol
A Körtvély1, G Szigeti, R Gesztelyi
1Department of Physiology, University Medical School of Debrecen, Hungary.
Insights
BRX-005, a novel heat shock protein coinducer, enhances heart contractility and blood vessel relaxation without altering intracellular calcium levels. This cardioprotective agent shows direct effects on vascular smooth muscle.
Area of Science:
- Pharmacology
- Cardiovascular Physiology
- Molecular Biology
Background:
- Heat shock proteins (HSPs) play crucial roles in cellular protection and stress response.
- Novel coinducers of HSPs are being investigated for therapeutic potential in cardiovascular diseases.
- Understanding the mechanisms of cardioprotective and vasoprotective agents is vital for drug development.
Purpose of the Study:
- To investigate the concentration-dependent effects of BRX-005 on cardiac contractility and intracellular calcium handling.
- To evaluate the vasorelaxant properties of BRX-005 in vascular smooth muscle.
- To compare the effects of BRX-005 with bimoclomol, another HSP coinducer.
Main Methods:
- Langendorff-perfused guinea pig hearts loaded with Fura-2 for calcium transient analysis.
- Measurement of left ventricular pressure, contractility, and relaxation rates.
- Electrophysiological studies on canine ventricular cardiomyocytes.
- Assessment of vasorelaxation in precontracted guinea pig pulmonary artery preparations.
Main Results:
- BRX-005 significantly increased peak left ventricular pressure, force development, and relaxation in a concentration-dependent manner.
- The amplitude of intracellular calcium ([Ca2+]i) transients remained unaltered by BRX-005.
- BRX-005 induced concentration-dependent relaxation in guinea pig pulmonary arteries, independent of endothelium.
- Bimoclomol increased contractility and [Ca2+]i transient amplitude, and suppressed action potential upstroke in cardiomyocytes.
Conclusions:
- BRX-005 exhibits potent cardioprotective effects by enhancing contractility and relaxation without affecting intracellular calcium transients.
- The vasorelaxant effect of BRX-005 is mediated directly on vascular smooth muscle.
- BRX-005 represents a promising therapeutic agent with distinct mechanisms compared to bimoclomol.
Abstract:
Concentration-dependent effects of BRX-005, the novel heat shock protein coinducer, cardioprotective and vasoprotective agent, on intracellular calcium transients and contractility were studied in Langendorff-perfused guinea pig hearts loaded with the fluorescent calcium indicator dye Fura-2. BRX-005 increased peak left ventricular pressure, the rate of force development and relaxation significantly in a concentration-dependent manner. The amplitude of [Ca2+]i transients was left unaltered by the drug. In contrast to BRX-005, bimoclomol increased both contractility and the amplitude of [Ca2+]i transients. In canine ventricular cardiomyocytes high concentrations of BRX-005 had no effect on depolarization, whereas bimoclomol suppressed action potential upstroke markedly. In guinea pig pulmonary artery preparations precontracted with phenylephrine, BRX-005 induced concentration-dependent relaxation. This effect of BRX-005 was independent of the integrity of endothelium indicating that vasorelaxant effect of the drug develops directly on vascular smooth muscle.