open access

Vol 63, No 4 (2004)
ORIGINAL ARTICLES
Published online: 2004-09-16
Submitted: 2012-02-06
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Myocardial necrosis due to vitamin D3 overdose - scanning electron microscopic observations

Olga Walentynowicz, Jolanta Kubasik-Juraniec, Teresa Rudzińska-Kisiel
Folia Morphol 2004;63(4):439-444.

open access

Vol 63, No 4 (2004)
ORIGINAL ARTICLES
Published online: 2004-09-16
Submitted: 2012-02-06

Abstract

Our studies were carried out on the hearts of virgin female Wistar rats treated with 100.000 i.u. of vitamin D3 (calciol) per os for 3 consecutive days. Multifocal cardionecrosis was established macroscopically in 70% of the vitamin D-treated rats on the 7th day of the experiment when the rats were in the acute phase of intoxication. Using a scanning electron microscopy (SEM), we received three-dimensional information about the structural changes to the rat myocardium damaged by high doses of vitamin D3. The images of necrotic hearts revealed significant disruption of the structural integrity of the myocardium linked to fragmentation of the cardiac muscle bundles and a visible disruption of the extracellular matrix (ECM) components. In healthy hearts, the structural integrity of the myocardium and the dense network of the extracellular matrix were well preserved. In parallel, the effect of an increasing concentration of free Ca2+ on the total proteolytic activity of the heart muscle homogenate of the healthy and necrotic rats was investigated at neutral pH. These data showed that following vitamin D3 intoxication, the proteolytic processes in the rat hearts occurred in Ca2+ overload or saturation. On the basis of our morphological and biochemical results we can suggest that calcium-activated neutral proteinases may have contributed to the structural alteration of the extracellular matrix components and were in this way involved in vitamin D-induced cardionecrosis.

Abstract

Our studies were carried out on the hearts of virgin female Wistar rats treated with 100.000 i.u. of vitamin D3 (calciol) per os for 3 consecutive days. Multifocal cardionecrosis was established macroscopically in 70% of the vitamin D-treated rats on the 7th day of the experiment when the rats were in the acute phase of intoxication. Using a scanning electron microscopy (SEM), we received three-dimensional information about the structural changes to the rat myocardium damaged by high doses of vitamin D3. The images of necrotic hearts revealed significant disruption of the structural integrity of the myocardium linked to fragmentation of the cardiac muscle bundles and a visible disruption of the extracellular matrix (ECM) components. In healthy hearts, the structural integrity of the myocardium and the dense network of the extracellular matrix were well preserved. In parallel, the effect of an increasing concentration of free Ca2+ on the total proteolytic activity of the heart muscle homogenate of the healthy and necrotic rats was investigated at neutral pH. These data showed that following vitamin D3 intoxication, the proteolytic processes in the rat hearts occurred in Ca2+ overload or saturation. On the basis of our morphological and biochemical results we can suggest that calcium-activated neutral proteinases may have contributed to the structural alteration of the extracellular matrix components and were in this way involved in vitamin D-induced cardionecrosis.
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Keywords

cardiac myocytes; calciol; toxicity; extracellular matrix; calpain

About this article
Title

Myocardial necrosis due to vitamin D3 overdose - scanning electron microscopic observations

Journal

Folia Morphologica

Issue

Vol 63, No 4 (2004)

Pages

439-444

Published online

2004-09-16

Bibliographic record

Folia Morphol 2004;63(4):439-444.

Keywords

cardiac myocytes
calciol
toxicity
extracellular matrix
calpain

Authors

Olga Walentynowicz
Jolanta Kubasik-Juraniec
Teresa Rudzińska-Kisiel

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