Histology and histochemistry of atherosclerotic lesions in the pit fowl hen vascular system

• Main Author: Gerity, Peter Francis
• Other Authors: Zoology
• Format: Others
• Language: en_US
• Published: Virginia Polytechnic Institute and State University 2015
• Subjects: LD5655.V856 1971.G47; Poultry
• Online Access: http://hdl.handle.net/10919/53900

Iliac complexes from pit fowl hens, in 3 groups of 8 animals each having mean ages of 1.0, 2.5, and 4.4 years, were examined histologically and histochemically for spontaneous atherosclerotic plaques. The purpose being (1) clarification of the role of specific arterial components in elaboration of plaques; (2) demonstration of specific protein polysaccharide involvement in the etiology of these lesions; and (3) quantitation of these compounds. Examination of vessels indicated plaque severity ranged from 2.83 to 4.91 (total intimal involvement) to 3.50 for animals 1.0, 2.5, and 4.4 years of age. Plaque severity data suggest a normal curve with its mid-point at 2.5 years, while plaque frequency data increase linearly from 37.5% to 87.6%. Spontaneous plaques were characterized by (1) vacuolization of the intima; (2) marked elastic fiber fragmentation in the intimal and medial regions; and (3) alterations to medial collagen and protein- polysaccharides. Significant (P ≤. 05) adventitial reduction accompanied aging and plaque development. Media dimensions simulate a normal curve accompanying age, with mean thickness of 79.10 μ, 159.52 μ, and 98.83 μ for birds of 1.0, 2.5, and 4.4 years. All ages exhibited increased medial thickness in plaque-containing vessels. Intima dimensions of the three age groups simulate a normal curve with mean thickness of 27.37 μ, 50.29 μ, and 36.80 μ for animals 1.0, 2.5, and 4.4 years, respectively. Plaque-vessels exhibited significant intimal thickening from 6.0 μ, non- plaque, to 65.96 μ for plaque-vessels. Mean bore diameters for the three ages approximate a normal curve with 254.52 μ, 326.03 μ, and 251.61 μ being significantly different for animals of 1.0, 2.5, and 4.4 years, respectively. Bore diameters of plaque-vessels were reduced significantly. lliac O. D. for all ages differed significantly with 666.00 μ, 998.64 μ, and 662.55 μ observed for animals 1.0, 2.5, and 4.4 years, respectively. Toluidin blue-O, pH 4.9 produced marked staining response, and intense gamma metachromasia in the media of plaque-vessels, indicating carbohydrate alterations. Decreased response to toluidin blue-O, pH 2. 6 was observed in plaque-vessels. Intimal response to toluidin blue-O, pH 4.9, and 3.4 exhibited peak intensity at age 2.5 years. Iliac complexes of animals 1.0, 2.5, and 4.4 years contained 26.2%, 37.1%, and 14.5% elastin, respectively. While non-plaque vessels exhibited a linear increase from 36.7% to 50.3% and 58.8%, plaque-vessels exhibited severe fragmentation and significant decrease in elastin to 8.8%, 32.7%, and 8.2% in birds 1.0, 2.5, and 4.4 years. Arterial collagen decreased with age from 15.3%, 14.8%, to 7.5% for birds 1.0, 2.5, and 4.4 years. Plaque vessels of birds 1.0 and 4.4 years of age showed decreased collagen content, while those of 2.5 years increased. The pooled mean, however, indicates significant collagen reduction in plaque-vessels. Animals 2.5 and 4.4 years of age exhibited no significant difference for serum cholesterol between plaque and non-plaque animals. Significant differences between age groups, however, were noted. === Ph. D.