Biologia, Bratislava, 55/Suppl. 8: 119-124, 2000.

ISSN 0006-3088 (Biologia). ISSN 1335-6399 (Biologia. Section Cellular and Molecular Biology).

 

Full Paper

Histological analysis of mouse aorta after overload with cholesterol and g-radiation.

 

Dana Tazka1*, Jindra Valentova2, Jan Kyselovic1, Jozef Seginko1 & Pavel Svec1

1 Department of Pharmacology and Toxicology, Faculty of Pharmacy, Comenius University, Kalinciakova 8, SK-83232 Bratislava, Slovakia; tel.: ++ 421 7 54259373, e-mail: tazka_dana@yahoo.com

2 Department of Chemical Theory of Drugs, Faculty of Pharmacy, Comenius University, Kalinciakova 8, SK-83232 Bratislava, Slovakia

* corresponding author

Received: July 10, 2000 / Accepted: October 24, 2000

 

Abstract

Considerable epidemiological, experimental and clinical trial data support a strong association between cholesterol and free radicals in atherogenesis. We evaluated the  synergicstic effect of dietary cholesterol excess and g radiation exposure on the development of atherosclerotic lesions in the mouse aorta. Mice were divided into six experimental groups. Each group was maintained on a specific condition: (1) standard chow, (2) 1% cholesterol diet, (3-4) radiation 8.5 Gy at 1.36 Gy/min., mice were sacrificed 24 hours  or 10 days after radiation, respectively, (5-6) 1% cholesterol diet + radiation 8.5 Gy at 1.36 Gy/min, mice were sacrificed 24 hours or 10 days after radiation, respectively. Cholesterol plasma level and thiobarbituric acid-reactive substances (TBARs) in the liver were measured. The aorta was processed by standard histological staining techniques hematoxylin/eosin, oil red stain for lipids and elastic fibre staining according to Weighert. Administration of 1% cholesterol diet was associated with an increased cholesterol concentration in plasma, increased lipid accumulation in the subendothelial regions and fragmentation of the lamina elastica interna. Exposure to g radiation produced destruction of the endothelium as well as an increased production of TBARs in the liver. In mice sacrificed 24 hours after irradiation with cholesterol diet, lipid accumulation was distributed in the whole aortic cross-sectional  region. Increased TBARs were also detected. In animals sacrificed 10 days after irradiation, lipid accumulation was reduced and concentrated mainly in the intima. In this group of mice, the concentration of TBARs was reduced. Histological analysis of sections stained according to Weighert showed disorganisation of elastic lamellae in the group of mice with or without high cholesterol diet after g radiation exposure. Combination of dietary cholesterol excess and g irradiation induced a significant increase in cholesterol accumulation, free radical production and significant structural changes in the mouse aorta.