Barium cardiotoxicity: Relationship between ultrastructural damage and mechanical effects.

Area of Science:

• Cardiovascular Physiology
• Cell Biology
• Toxicology

Background:

• Barium ions are known to affect cardiac membrane permeability.
• The precise mechanisms of barium-induced myocardial toxicity remain incompletely understood.

Purpose of the Study:

• To investigate the ultrastructural damage in guinea-pig ventricular strips induced by barium chloride.
• To determine if increased heart rate alone accounts for barium-induced cellular damage.

Main Methods:

• Guinea-pig ventricular strips were exposed to 1 mmol/litre barium chloride.
• Ultrastructural analysis was performed on myocytes.
• Preparations were driven at 4 Hz to simulate spontaneous firing rates.

Main Results:

• Barium chloride significantly increased developed tension and induced automaticity.
• Consistent ultrastructural alterations were observed in mitochondria and contractile apparatus.
• Glycogen deposits were completely depleted.
• Moderate damage occurred at 4 Hz, indicating rate is not the sole factor.

Conclusions:

• Barium induces significant myocardial toxicity beyond membrane permeability changes.
• Cellular function alterations likely contribute to barium's cardiotoxic effects.
• Further research into barium's impact on cellular processes is warranted.