Frequency of spontaneous tumors in Wistar rats in 30-months studies.

摘要: Tumors occurring in 450 male and female control rats of the strain Wistar (BOR:WISW (SPF Cpb), breeder: Winkelmann, Borchen) employed 9 groups from 7 different 30-month studies were compiled on basis histopathology reports. 445 448 evaluated. The remaining animals unavailable due to autolysis. A total 1211 tumors (565 males, 646 females) seen 716 (333 383 females), 251 which classified as malignant (100 151 females). About 44% all primary located pituitary adrenals alone. Average frequencies tumors: 35.4%, uterus 34.0%, 26.5%, testes 15.8%, thyroid gland 11.8%, mammary glands 11.4% 22.5% females respectively, skin/subcutis 6.3%, ovaries 2.9%, endocrine pancreas 2.5%, hemolymphoreticular system 2.3%, liver 1.9%, heart 1.7% various other organs showing tumor less than 1.5%. Male exhibited strikingly more adrenals, skin, pancreas, brain, while predominant females. comparison these data with those 24-month same breeder shows a considerable increase above number tumors, bearers well pituitary, testes, heart. An extension carcinogenicity 30 months probably makes it harder recognise tumorigenic effects test substances, at least some organs, two-year because high variable spontaneous rates.