Limits...
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 amiodarone-treated rats. A. A semithin section showing abnormal pattern of striations (stars), disrupted intercalated discs (arrow) and abnormal mitochondrial arrangements (double arrows). B. Dissociation of myofibrils (stars) with irregularities and destruction of myofibrils and intercalated disc (arrow) (Bar = 200 nm). C. Dissociation of myofibrils (stars) with irregularities of the sarcomere and lesser concentration of ANF granules (An) with disrupted nuclear (N) chromatin contents (Bar = 1 µm). D. Swollen mitochondria (M) with loss of its cristae in some and loss of its pattern in others. Empty spaces in between myofibrils (m) and fibres (F) were noted in the intercellular space (Bar = 1 µm). (x: 1000).
© Copyright Policy - open access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3376877&req=5

Figure 2: Electron micrographs from cardiac atria of amiodarone-treated rats. A. A semithin section showing abnormal pattern of striations (stars), disrupted intercalated discs (arrow) and abnormal mitochondrial arrangements (double arrows). B. Dissociation of myofibrils (stars) with irregularities and destruction of myofibrils and intercalated disc (arrow) (Bar = 200 nm). C. Dissociation of myofibrils (stars) with irregularities of the sarcomere and lesser concentration of ANF granules (An) with disrupted nuclear (N) chromatin contents (Bar = 1 µm). D. Swollen mitochondria (M) with loss of its cristae in some and loss of its pattern in others. Empty spaces in between myofibrils (m) and fibres (F) were noted in the intercellular space (Bar = 1 µm). (x: 1000).

Mentions: Sections from atria of rats administered amiodarone alone, showed ultrastructural changes. Loss of myocardial organisation, a scattered area of degenerated cardiomyocytes, and myofibrillar disarray were apparent. Wavy myofibrils, abnormal pattern of striations, disrupted intercalated discs and abnormal mitochondrial arrangements were identified (Fig. 2A). Myofilaments derangement, partial necrosis, intercalated disc dissociation and disintegration of filaments were also observed (Fig. 2B). Irregularities of the sarcomere, lower concentration of ANF granules in the perinuclear area and disrupted nuclear chromatin were clearly observed (Fig. 2C). In addition, swollen mitochondria with lysis of its cristae and dissolution of the matrix were clearly observed. The intermembrane space of the mitochondria had expanded. In addition, specimens revealed decreased density of the sarcoplasm and marked heterogeneity in the myofibril pattern with ruptures and loss of continuity of the myofilaments (Fig. 2D).


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 amiodarone-treated rats. A. A semithin section showing abnormal pattern of striations (stars), disrupted intercalated discs (arrow) and abnormal mitochondrial arrangements (double arrows). B. Dissociation of myofibrils (stars) with irregularities and destruction of myofibrils and intercalated disc (arrow) (Bar = 200 nm). C. Dissociation of myofibrils (stars) with irregularities of the sarcomere and lesser concentration of ANF granules (An) with disrupted nuclear (N) chromatin contents (Bar = 1 µm). D. Swollen mitochondria (M) with loss of its cristae in some and loss of its pattern in others. Empty spaces in between myofibrils (m) and fibres (F) were noted in the intercellular space (Bar = 1 µm). (x: 1000).
© Copyright Policy - open access
Related In: Results  -  Collection

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

Figure 2: Electron micrographs from cardiac atria of amiodarone-treated rats. A. A semithin section showing abnormal pattern of striations (stars), disrupted intercalated discs (arrow) and abnormal mitochondrial arrangements (double arrows). B. Dissociation of myofibrils (stars) with irregularities and destruction of myofibrils and intercalated disc (arrow) (Bar = 200 nm). C. Dissociation of myofibrils (stars) with irregularities of the sarcomere and lesser concentration of ANF granules (An) with disrupted nuclear (N) chromatin contents (Bar = 1 µm). D. Swollen mitochondria (M) with loss of its cristae in some and loss of its pattern in others. Empty spaces in between myofibrils (m) and fibres (F) were noted in the intercellular space (Bar = 1 µm). (x: 1000).
Mentions: Sections from atria of rats administered amiodarone alone, showed ultrastructural changes. Loss of myocardial organisation, a scattered area of degenerated cardiomyocytes, and myofibrillar disarray were apparent. Wavy myofibrils, abnormal pattern of striations, disrupted intercalated discs and abnormal mitochondrial arrangements were identified (Fig. 2A). Myofilaments derangement, partial necrosis, intercalated disc dissociation and disintegration of filaments were also observed (Fig. 2B). Irregularities of the sarcomere, lower concentration of ANF granules in the perinuclear area and disrupted nuclear chromatin were clearly observed (Fig. 2C). In addition, swollen mitochondria with lysis of its cristae and dissolution of the matrix were clearly observed. The intermembrane space of the mitochondria had expanded. In addition, specimens revealed decreased density of the sarcoplasm and marked heterogeneity in the myofibril pattern with ruptures and loss of continuity of the myofilaments (Fig. 2D).

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