Microscopic Findings in Seminal Vesicles of Control Rats Mated to Females From Fertility and Early Embryonic Development Studies

Male reproductive organs are rarely examined microscopically in developmental and reproductive toxicity (DART) studies. Therefore, few background histopathological data exist for breeding animals. Yet, toxicologic pathologists must be able to recognize spontaneous lesions in a particular organ or tissue so that these changes are not incorrectly attributed to the test item. Inflammation of the secondary sex organs is described as a common background finding in laboratory rats and mice. Breeding activity may increase the risk of infection of the male accessory glands. In the present communication, we report microscopic changes in seminal vesicles observed in Control rats mated to Control females from three fertility and early embryonic development (FEED) studies. Acute inflammation, inflammatory cell infiltrate, hypertrophy, and increased apoptosis of the glandular epithelium were frequent findings.