Spontaneous Atrial Thrombosis in Aged Syrian Hamsters

Abstract

SummaryMany of the aging Syrian hamsters maintained in our Division spontaneously develop atrial thrombosis accompanied by a consumption coagulopathy. The 50% mortality level is reached earlier by females (16 months) than by males (24 months). The incidence of thrombosis increases with age, beginning at 13.5 months in females and at 21.5 months in males, and the overall incidence (73%) is nearly the same for both sexes. Bilateral ventricular hypertrophy was found in thrombosed hearts. The hearts of most aged hamsters, whether thrombosed or not, had myxoid valvular thickenings and myocardial degeneration. Myodystrophic changes included hypertrophied nuclei, cytoplasmic vacuolation, fiber atrophy, and finally replacement fibrosis. Thrombosis probably resulted from local blood stasis secondary to cardiac failure. These hamsters may be an especially useful model for comparative study of the effects of aging and myocardial degeneration on spontaneous thrombosis.

Age-related non-neoplastic lesions in the heart and kidneys of Syrian hamsters of the APA strain

“…The histopathology of cardiac lesions in the present study closely resembles that described by McMartin (1977) for his hamster colony. Additional findings such as occasional pericarditis in a thrombosed left atrium and chondroid metaplasia in one thrombosed mitral valve were noticed in the present study.…”

“…There was also an age-related increase in both absolute and relative heart weight, suggesting cardiac hypertrophy in older APA hamsters. The incidence of cardiac thrombosis in APA hamsters was not as high as reported by McMartin (1977); however, it was relatively high compared with data for other hamster colonies (Chesterman, 1972;Pour et al, 1976Pour et al, , 1979.…”

“…Furthermore there was no apparent correlation between the existence of cardiac thrombosis and the severity of renal lesions in the present study. Since myocardial degeneration, myxoid valvular thickening and cardiac hypertrophy were common in older APA hamsters, cardiac thrombosis probably resulted from local blood stasis secondary to cardiac failure as was also observed by McMartin (1977) in his hamster colony.…”

Spontaneous Nonneoplastic Lesions in Control Syrian Hamsters in Three 24-month Long-term Carcinogenicity Studies

“…This lesion is related to the severe cardiac insufficiency caused by left atrial thrombosis. Atrial thrombosis is noted at a high incidence in older hamsters (McMartin 1977). Male and female Syrian hamsters have an equally high incidence of atrial thrombosis and myocardial degeneration, despite the females' much shorter life span (McMartin 1979).…”

Biology and Diseases of Hamsters

“…The exact incidence varies greatly, from 16% reported in one colony to 73% incidence in another (McMartin, 1977;Pour, 1976a). The exact incidence varies greatly, from 16% reported in one colony to 73% incidence in another (McMartin, 1977;Pour, 1976a).…”