Experimental Coronary Arteriography

A study of arteriography of experimentally induced coronary arterial lesions requires a reliable method of producing such lesions in a model animal. Arterial lesions, often designated atherosclerotic, may result from repeated experimental vascular injuries by a variety of agents. A necrotizing arteritis may be produced, characterized by fibrinoid necrosis of the media and more or less cellular exudate involving the vessel wall and periadventitial tissues. The technics have included, among others, the induction of renal ischemia in dogs (4, 12), sensitization of rabbits by the injection of horse serum (8), and unilateral nephrectomy in rats, combined with injections of desoxycorticosterone (9). Segmental necrosis of the arterial wall following subcutaneous injection of trypsin has also been noted (7). While experimental atherosclerosis can be satisfactorily produced in a variety of animals, attempts to produce it in the dog have proved singularly difficult. Moreover, although the experimental production of atherosclerotic vascular lesions resulting in myocardial and renal infarctions in rats (6), chickens (6), and rabbits (1, 5), has been successfully achieved, few of these animals can be employed for critical assessment of coronary arteriographic technics. Furthermore, while dogs have been used widely in coronary arteriography studies, a reliable method of producing coronary arterial lesions similar to those which occur in man has been lacking. In view of previous experience with the allylamine-injured dog (2, 3, 10), the study to be reported here was undertaken to determine whether or not dogs could serve as experimental models for the evaluation of coronary arteriography. The material summarizes the progressive manifestations, gross alterations, extent, and distribution of vascular lesions characterizing allylamine injury in the dog. Subsequent investigations to determine whether or not the lesions thus produced can be demonstrated by means of arteriography are reported elsewhere. Material and Methods Forty adult mongrel dogs were maintained on a low-fat standard laboratory diet. Allylamine, a strong base, was prepared for injection in 1 per cent aqueous solution neutralized with hydrochloric acid and buffered to pH 7.4. Fifteen milligrams of the base per kilogram of body weight was introduced intravenously, 3 such injections being carried out every other day. At the dose level utilized, severe immediate reactions were avoided. Following the administration of allylamine, 6 intravenous injections of high-viscosity methylcellulose were given at two-day intervals, in the form of a 2 per cent aqueous solution, at dosage levels of 1 ml. per kilogram of body weight. Animals dying during the injection period were autopsied and sections of the myocardium were taken from all cardiac chambers and stained with hematoxylin and eosin, Verhoeff's elastic tissue stain, and Masson's trichrome stain.