As simvastatin is the most prescribed and distributed drug for high cholesterol by the National Health Service the authors carry out an experimental work to study special detailed effects of this drug. The authors studied the effect of simvastatin on the development of atherosclerotic lesions in aortas of rabbits submitted to a high-cholesterol diet, at 1.5%. The authors studied 30 New Zealand rabbits, males, adults, distributed in three groups according to diet: (A) cholesterol, (B) cholesterol + simvastatin (100 mg/day) and (C) normal. We took blood samples to evaluate cholesterol and plasma triglycerides at times zero, five and nine weeks and found lower serum cholesterol levels in the treated group. After nine weeks, we sacrificed the animals and examined the aortas for the extent of the atheromatous lesion area evaluated by computerized planimetry and the height of the lesion analyzed by morphometry, in histological sections of thoracic and abdominal aorta. There was no statistically significant difference between groups A and B in relation to the percentage of the injured area. However, in rabbits treated with simvastatin, smoother and less relief lesions were observed macroscopically by us and confirmed by morphometric analyses of atheroma plaque thickness. We observed intense morphological changes in the liver of the two groups of animals with a hypercholesterolemic diet, although to a slightly lower degree in those treated with simvastatin. We concluded that simvastatin had a protective effect on the volume of atherosclerotic lesions in aortas of hypercholesterolemic rabbits.
Read full abstract