Evaluation of the effect of cicletanine on genetic atherosclerosis in the rabbit

This study was designed to evaluate the hypolipidaemic and anti-atherosclerotic potential of cicletanine in a genetic hypercholesterolaemic rabbit model. In a pilot study the effect of 8 weeks oral administration of 2 treatment levels of cicletanine (10, 30 mg.kg-1.day-1) was compared with vehicle alone. In the main study, 8 weeks oral administration of 2 treatment levels of cicletanine (5, 30 mg.kg-1.day-1) was compared with parallel treatment with probucol (15 mg.kg-1.day-1) and with nifedipine (10 mg.kg-1.day-1). At the start of each study and at scheduled points throughout, blood samples were collected for routine biochemical and lipid/lipoprotein analyses. At the end of each test period all animals were examined at post mortem. Aortae were dissected and examined for the presence ans degree of atheroma. Hearts were examined for the presence of lesions. Sections of aortae were stained for lipid, examined histologically and scored for extent of atheroma using an atherosclerotic index. In the pilot study cicletanine had no effect on blood lipid levels. Gross pathology indicated a reduction in the extent of aortic atheroma in cicletanine-treated animals. Histopathological examination of thoracic and abdominal regions of the aortae confirmed these gross findings. The atherosclerotic index was significantly reduced (p less than 0.06) in all drug treated animals. In the main study similar data were achieved. None of the test drug affected plasma lipid/lipoprotein levels. Gross pathology indicated a reduction in the extent of aortic atheroma in all cicletanine-treated animals and also in the nifedipine-treated group. This was confirmed by histopathological examination of thoracic and abdominal regions of the aortae.(ABSTRACT TRUNCATED AT 250 WORDS)