An immunocytochemical study of pituitary adenomas and focal hyperplasia in old Sprague-Dawley and Fischer 344 rats.
Spontaneous pituitary tumors occurring in groups of 100 Sprague-Dawley (SD) and 100 Fischer 344 (F344) rats of each sex on a 2-year aging study were characterized by immunocytochemistry. The SD strain had a total of 75 tumors with 10% in males and 65% in females. Tumors immunoreactive for prolactin (PRL) alone were the most common tumor (64%) with the immunonegative tumor being the second most common (17.3%). F344 rats had a total of 62 tumors with 26% in males and 36% in females. The majority of the tumors were reactive for prolactin alone (56.5%) and tumors reactive for both growth hormone (GH) and PRL were the second most common (21%). Most tumors were immunoreactive for only 1 hormone; however, both strains had tumors that expressed multiple hormones in unusual combinations.
Sandusky
G E
GE
Pathology Department, Lilly Research Laboratories, Division of Eli Lilly and Company, Greenfield, Indiana 46140.
Van Pelt
C S
CS
Todd
G C
GC
Wightman
K
K
D000236:Adenoma / Q000032:analysis*; D000818:Animals; D005260:Female; D006965:Hyperplasia; D007150:Immunohistochemistry; D008297:Male; D010902:Pituitary Gland / Q000473:pathology*; D010907:Pituitary Hormones / Q000032:analysis*; D010911:Pituitary Neoplasms / Q000032:analysis*; D011388:Prolactin / Q000032:analysis; D051381:Rats; D011916:Rats, Inbred F344; D011919:Rats, Inbred Strains; D013045:Species Specificity
D010907:Pituitary Hormones; D011388:Prolactin