OM, Rat Strain

**Semantic type:** Mammal

**Definition:** Spontaneous thyroid carcinoma 33% (Lindsey et al 1968). Adrenal cortical tumors 94% and pituitary tumors 8-18% at 18 months (Hansen et al 1973). In animals over 18 months Snell found adenomas or carcinomas of adrenal cortex 73% in males and 95% in females, pituitary tumors 25%, granulosa cell tumors of the ovary 33% in females. High blood pressure (3/23), reaching 154+/-1.0 (SEM) mmHg at 10 weeks of age (Tanase et al 1982). Mammary tumors 26-30%. High incidence of retinal degeneration in animals over 10 months (von Sallman and Grimes 1972, 1974). High systolic blood pressure (2/17) (Hansen et al 1973).