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In vivo administration of MKT-077 causes partial yet reversible impairment of mitochondrial function
E L Weisberg1, K Koya, J Modica-Napolitano
1Dana-Farber Cancer Institute, Division of Cellular and Molecular Biology, Harvard Medical School, Massachusetts 02115, USA.
Abstract:
The effects of in vivo administration of a pharmacologically toxic dose of the lipophilic cationic compound, MKT-077, were investigated in selected vital organs of the rat. MKT-077 (15 mg/kg body weight), administered by bolus i.v. injection every day for 5 days, did not detectably influence rat heart and kidney mitochondrial respiration. Although the same dosage of MKT-077 significantly decreased respiratory rates in rat liver mitochondria relative to untreated controls, complete recovery was evident within 3 days following drug withdrawal. Whereas the mitochondrial DNA of rat kidney and liver appeared to be unaffected by MKT-077 treatment, levels of heart mtDNA were noticeably less than control levels in the immediate interval following drug administration. However, this latter effect was partially reversed as early as 10 days following treatment and completely reversed within a 30-day posttreatment period. These results strongly suggest that a pharmacologically toxic dose of MKT-077 minimally affects the overall functional integrity of mitochondria in such critical, although highly vulnerable, tissues as the heart, liver, and kidney.
Insights
Pharmacologically toxic doses of MKT-077 minimally impacted heart and kidney mitochondrial respiration in rats. Liver mitochondria showed temporary decreases, with full recovery after MKT-077 withdrawal.
Area of Science:
- Pharmacology
- Toxicology
- Mitochondrial Biology
Background:
- MKT-077 is a lipophilic cationic compound.
- Investigating the effects of toxic doses is crucial for understanding drug safety.
- Vital organs like the heart, liver, and kidney are susceptible to drug-induced toxicity.
Purpose of the Study:
- To investigate the effects of a pharmacologically toxic dose of MKT-077 on mitochondrial function in rat heart, liver, and kidney.
- To assess the impact on mitochondrial respiration and mitochondrial DNA (mtDNA) integrity.
- To determine the reversibility of any observed effects post-treatment.
Main Methods:
- In vivo administration of MKT-077 (15 mg/kg) daily for 5 days in rats.
- Measurement of mitochondrial respiration in heart, liver, and kidney homogenates.
- Quantification of mtDNA levels in heart, liver, and kidney tissues at various time points.
Main Results:
- MKT-077 did not affect heart and kidney mitochondrial respiration.
- Liver mitochondrial respiration rates decreased significantly but recovered within 3 days post-treatment.
- Heart mtDNA levels decreased immediately post-administration but showed partial and complete recovery within 10 and 30 days, respectively. Kidney and liver mtDNA were unaffected.
Conclusions:
- A pharmacologically toxic dose of MKT-077 has minimal impact on the overall functional integrity of mitochondria in the heart, liver, and kidney.
- Observed effects on liver respiration and heart mtDNA are largely reversible.
- MKT-077 demonstrates a degree of organ-specific mitochondrial safety at toxic doses.