Abstract Background

The mechanism of atherogenesis is not yet fully understood despite intense study in this area.

The effects of high fat diet (HFD) on the changes of trace elements [iron (Fe), copper (Cu) and zinc (Zn)] in several tissues of rabbits have not been documented before.

Thus, the aim of this study was to elucidate the changes in trace elements in several tissues of rabbits fed on HFD for a period of feeding of 10 weeks.

Results The HFD group was fed a NOR rabbit chow supplemented with 1.0% cholesterol plus 1.0% olive oil.

Fe, Cu and Zn concentrations were measured in four types of tissue from control and HFD rabbits using atomic absorption spectroscopy (AAS).

Comparing HFD rabbits to control rabbits, we found that the highest percentage change of increase of Fe was 95% in lung tissue, while the lowest percentage change of increase of Fe was 7% in kidney tissue; the highest percentage change of decrease of Cu was 16% in aortic tissue, while the lowest percentage change of decrease of Cu was 6% in kidney tissue; and the highest percentage change of decrease of Zn was 71% in kidney tissue, while the lowest percentage change of decrease of Zn was 8% in lung tissue.

Conclusions

These results suggest that Fe plays a major role in atherogenesis; it may accelerate the process of atherosclerosis probably through the production of free radicals, deposition and absorption of intracellular and extracellular lipids in the intima, connective tissue formation, smooth muscle proliferation, lower matrix degradation capacity and increased plaque stability.

Furthermore, inducing anemia in HFD rabbits may delay or inhibit the progression of atherosclerosis. Cu plays a minor role in atherogenesis and Cu supplements may inhibit the progression of atherogenesis, perhaps by reducing the migration of smooth muscle cells from the media to the intima.

Zn plays a major role in atherogenesis and that it may act as an endogenous protective factor against atherosclerosis perhaps by reducing lesion Fe content, intracellular and extracellular lipids in the intima, connective tissue formation, and smooth muscle proliferation.

These results suggest that it may be possible to use the measurement of changes in trace elements in different tissues of rabbits as an important risk factor during the progression of atherosclerosis.

•  Other Sections▼
  • Abstract
  • Background
  • Methods
  • Results
  • Discussion
  • Conclusions
  • Abbreviations
  • Competing interests
  • Authors' contributions
  • References

Background

Atherosclerosis is a disease of large- and medium-sized arteries, and is characterized by endothelial dysfunction (malfunction of the cells lining the inside of the artery wall), vascular inflammation, migration of smooth muscle cells to the inner lining of the artery (intima) and the build-up of lipids, cholesterol and cellular debris within the intima of the vessel wall.

The biological mechanisms by which low density lipoprotein (LDL) promote formation of atherosclerotic plaques are still poorly understood.

Oxidation of LDL has been found to increase its uptake in macrophages and lead to formation of macrophage foam cells.

Other studies have indicated that oxidized LDL may induce vascular inflammation and even give rise to autoimmune reactions in the vascular wall.

These activated macrophages produce numerous factors that are injurious to the endothelium, leading to plaque formation.

In later stages, calcification in the damaged region leads to hardening of the artery wall, coupled with acute and chronic arterial obstruction [1-3].

Fe may participate in diverse pathological processes by catalyzing the formation of reactive oxygen free radicals.

The oxidation of LDL and lipid is believed to be one of the crucial events leading to plaque formation in vasculature.

It has been hypothesized that iron-mediated oxidation is involved in this process.

Several epidemiological studies have shown that the level of body Fe stores is positively correlated with the incidence of coronary heart disease in human populations.

Additional experiments in animals have further revealed that the severity of atherosclerosis can be markedly influenced by Fe overload or deficiency [4,5].

Cu supplements inhibit the progression of atherosclerosis by increasing superoxide dismutase (SOD) expression, thereby reducing the interaction of nitric oxide (NO) with superoxide, and hence potentiating NO-mediated pathways that may protect against atherosclerosis [6].

Zn supplementation decreased the elevated levels of cholesterol oxidation products in the aorta and plasma caused by eating a high-cholesterol diet. Several studies have shown that Zn reduced oxidative damage and the risk of cardiovascular disease.

Scientists have suggested that because Zn supplementation both reduced the formation of atheromas and lowered lipid peroxidation it may have antioxidant activity.

Since Zn is not redox active, it may not act directly as a scavenging antioxidant but instead may act as an indirect antioxidant by competing with pro-oxidant metals such as Fe and Cu for strategic binding sites [7-9].

The role of a high fat diet (HFD) on trace elements [iron (Fe), copper (Cu) and zinc (Zn)] in different tissues of rabbits has, in general, not been studied.

Thus, the aim of this study was to elucidate the effects of a HFD on trace elements (Fe, Cu and Zn) in different tissues of rabbits using atomic absorption spectroscopy (AAS).  

 Lipids Health Dis. 2010; 9: 2.

doi: 10.1186/1476-511X-9-2.  

Mohamed Anwar K Abdelhalim,¹ Hisham A Alhadlaq,¹ and Sherif Abdelmottaleb Moussa²

¹Department of Physics and Astronomy, College of Science, King Saud University, Saudi Arabia ²Department of Science, King Khalid Military College, Saudi Arabia

Corresponding author. Mohamed Anwar K Abdelhalim: abdelhalimmak@yahoo.com ;

Hisham A Alhadlaq: hhadlaq@ksu.edu.sa ;

Sherif Abdelmottaleb Moussa: sherifmoussa2006@yahoo.com

. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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