Coronary arterial lesions in sexually mature non-layers, layers, and roosters

The effects of hereditary hyperlipidemia on coronary artery atherosclerosis were studied in 77 White Leghorn (DeKalb strain) chickens ranging from 4 to 13 months in age. After pubescence, the plasma levels of triglyceride and cholesterol in non-laying hens ranged 2- to 3-fold and 2- to 7-fold higher compared to layers. Serial sectioning revealed that most lesions were found in the proximal portions of both the left and right coronary arteries. Ultrastructurally, lesions in the roosters contained no foam cells, whereas some foam cells and small amounts of stainable lipid were observed in the thickened intima of layers. Half of the non-layers had stenotic lesions characterized by many foam cells, necrotic foci, and heavy stromal lipid deposits. Continuous permeation of excess plasma lipids into the arterial wall appeared to be an important factor in the development of coronary lesions.