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Ultrastructural Changes in Rat's Atrial Cardiomyocytes After Short Term Administration of Amiodarone and Possible Protective Role of Vitamin E.

Shatoor AS, Zaki MS, Eid RA, Sayed-Ahmad MA - J Clin Med Res (2012)

Bottom Line: The use of amiodarone is associated with ultrastructural changes affecting body tissues, but its effect on the ultrastructure of the heart has not yet been fully elucidated.The aim of this study is to test the adverse effects of amiodarone administration on cardiomyocytes and to study the possible protective role of vitamin E co-administration.A total of 18 adult male albino rats were used in this study.

View Article: PubMed Central - PubMed

Affiliation: Internal Medicine Department, Cardiology Section, Faculty of Medicine, King Khalid University, Saudi Arabia.

ABSTRACT

Background: Amiodarone chlorhydrate is a diiodated benzofuran derivative used to treat a variety of cardiac rhythm abnormalities. The use of amiodarone is associated with ultrastructural changes affecting body tissues, but its effect on the ultrastructure of the heart has not yet been fully elucidated.

Methods: The aim of this study is to test the adverse effects of amiodarone administration on cardiomyocytes and to study the possible protective role of vitamin E co-administration. A total of 18 adult male albino rats were used in this study. The rats were divided randomly into three groups of 6 rats each as follows: group I was considered the control group and was given vegetable oil; group II received 54 mg/kg of oral amiodarone; and group III received a single dose of combined vitamin E (50 mg/kg) and amiodarone (54 mg/kg). After 2 weeks, the rats were sacrificed, and the atrial tissues were harvested and processed for electron microscopic study.

Results: ADMINISTRATION OF AMIODARONE ALONE MODIFIED THE ATRIAL ARCHITECTURE, WHICH WAS DEMONSTRATED BY THE FOLLOWING: mitochondrial enlargement and cristae lysis; marked heterogeneity of myofibril patterns with partial necrosis and disintegration of myofilaments; and irregularities of the sarcomere and less concentration of atrionatriuretic factor (ANF) granules, which localised in closed proximity to the nucleus with disrupted chromatin contents. Concomitant administration of vitamin E with amiodarone showed a considerable preservation of the atrial architecture.

Conclusions: Oral administration of amiodarone in rats resulted in ultrastructural changes in atria, which can be attenuated by vitamin E co-administration.

No MeSH data available.


Related in: MedlinePlus

Electron micrographs from cardiac atria of control rats. A. A semithin section showing clarified intercalated discs (arrows), typical cross striations of muscle fibres (star), and many rows of mitochondria (double arrows). (B) blood capillary. B. The striation pattern (stars) with its typical alteration and dense mitochondria (M) rich in cristae (Bar = 200 nm). C. The striation pattern (stars) with its typical alteration and dense mitochondria (M) rich in cristae, euchromatic nucleus (N) with its nucleolus (n) and closely packed atrionatriuretic factor (ANF) granules (An) (Bar =1 µm). D. The striation pattern (stars) with its typical alteration and step-like intercalated disc (arrow) with adherent fascia (Bar = 500 nm). (x: 1000).
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Figure 1: Electron micrographs from cardiac atria of control rats. A. A semithin section showing clarified intercalated discs (arrows), typical cross striations of muscle fibres (star), and many rows of mitochondria (double arrows). (B) blood capillary. B. The striation pattern (stars) with its typical alteration and dense mitochondria (M) rich in cristae (Bar = 200 nm). C. The striation pattern (stars) with its typical alteration and dense mitochondria (M) rich in cristae, euchromatic nucleus (N) with its nucleolus (n) and closely packed atrionatriuretic factor (ANF) granules (An) (Bar =1 µm). D. The striation pattern (stars) with its typical alteration and step-like intercalated disc (arrow) with adherent fascia (Bar = 500 nm). (x: 1000).

Mentions: Electron microscopic examination of the sections from the rat atria of the control group showed normal architecture. The mitochondria were packed together between myofibrils with some beneath the sarcolemma and some around the nucleus with visible intercalated discs (Fig. 1A). The striation pattern, with its typical alteration and dense mitochondria rich in cristae, was clearly visible in cardiac muscle (Fig. 1B). The euchromatic nucleus with its nucleolus and closely packed large atrionatriuretic factor (ANF) granules were noted (Fig. 1C). Higher magnification of step-like intercalated discs was revealed tight junctions and desmosomes (Fig. 1D).


Ultrastructural Changes in Rat's Atrial Cardiomyocytes After Short Term Administration of Amiodarone and Possible Protective Role of Vitamin E.

Shatoor AS, Zaki MS, Eid RA, Sayed-Ahmad MA - J Clin Med Res (2012)

Electron micrographs from cardiac atria of control rats. A. A semithin section showing clarified intercalated discs (arrows), typical cross striations of muscle fibres (star), and many rows of mitochondria (double arrows). (B) blood capillary. B. The striation pattern (stars) with its typical alteration and dense mitochondria (M) rich in cristae (Bar = 200 nm). C. The striation pattern (stars) with its typical alteration and dense mitochondria (M) rich in cristae, euchromatic nucleus (N) with its nucleolus (n) and closely packed atrionatriuretic factor (ANF) granules (An) (Bar =1 µm). D. The striation pattern (stars) with its typical alteration and step-like intercalated disc (arrow) with adherent fascia (Bar = 500 nm). (x: 1000).
© Copyright Policy - open access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3376877&req=5

Figure 1: Electron micrographs from cardiac atria of control rats. A. A semithin section showing clarified intercalated discs (arrows), typical cross striations of muscle fibres (star), and many rows of mitochondria (double arrows). (B) blood capillary. B. The striation pattern (stars) with its typical alteration and dense mitochondria (M) rich in cristae (Bar = 200 nm). C. The striation pattern (stars) with its typical alteration and dense mitochondria (M) rich in cristae, euchromatic nucleus (N) with its nucleolus (n) and closely packed atrionatriuretic factor (ANF) granules (An) (Bar =1 µm). D. The striation pattern (stars) with its typical alteration and step-like intercalated disc (arrow) with adherent fascia (Bar = 500 nm). (x: 1000).
Mentions: Electron microscopic examination of the sections from the rat atria of the control group showed normal architecture. The mitochondria were packed together between myofibrils with some beneath the sarcolemma and some around the nucleus with visible intercalated discs (Fig. 1A). The striation pattern, with its typical alteration and dense mitochondria rich in cristae, was clearly visible in cardiac muscle (Fig. 1B). The euchromatic nucleus with its nucleolus and closely packed large atrionatriuretic factor (ANF) granules were noted (Fig. 1C). Higher magnification of step-like intercalated discs was revealed tight junctions and desmosomes (Fig. 1D).

Bottom Line: The use of amiodarone is associated with ultrastructural changes affecting body tissues, but its effect on the ultrastructure of the heart has not yet been fully elucidated.The aim of this study is to test the adverse effects of amiodarone administration on cardiomyocytes and to study the possible protective role of vitamin E co-administration.A total of 18 adult male albino rats were used in this study.

View Article: PubMed Central - PubMed

Affiliation: Internal Medicine Department, Cardiology Section, Faculty of Medicine, King Khalid University, Saudi Arabia.

ABSTRACT

Background: Amiodarone chlorhydrate is a diiodated benzofuran derivative used to treat a variety of cardiac rhythm abnormalities. The use of amiodarone is associated with ultrastructural changes affecting body tissues, but its effect on the ultrastructure of the heart has not yet been fully elucidated.

Methods: The aim of this study is to test the adverse effects of amiodarone administration on cardiomyocytes and to study the possible protective role of vitamin E co-administration. A total of 18 adult male albino rats were used in this study. The rats were divided randomly into three groups of 6 rats each as follows: group I was considered the control group and was given vegetable oil; group II received 54 mg/kg of oral amiodarone; and group III received a single dose of combined vitamin E (50 mg/kg) and amiodarone (54 mg/kg). After 2 weeks, the rats were sacrificed, and the atrial tissues were harvested and processed for electron microscopic study.

Results: ADMINISTRATION OF AMIODARONE ALONE MODIFIED THE ATRIAL ARCHITECTURE, WHICH WAS DEMONSTRATED BY THE FOLLOWING: mitochondrial enlargement and cristae lysis; marked heterogeneity of myofibril patterns with partial necrosis and disintegration of myofilaments; and irregularities of the sarcomere and less concentration of atrionatriuretic factor (ANF) granules, which localised in closed proximity to the nucleus with disrupted chromatin contents. Concomitant administration of vitamin E with amiodarone showed a considerable preservation of the atrial architecture.

Conclusions: Oral administration of amiodarone in rats resulted in ultrastructural changes in atria, which can be attenuated by vitamin E co-administration.

No MeSH data available.


Related in: MedlinePlus