title: Functional characteristics of transplantable rat pituitary tumor MtT SA5 inducing pronounced adrenal hyperplasia.
abstract: Transplantable rat pituitary tumor MtT SA5 is characterized by the induction of pronounced adrenal enlargement. In spite of remarkable elevation of plasma ACTH levels, serum corticosterone levels in hypophysectomized tumor-bearing rats were lower than those in intact control rats. No immunohistochemical alterations were seen in corticotrophs of the pituitary in tumor-bearing rats. Ratio of bioactive ACTH (Bio-ACTH) to immunoreactive ACTH (Ir-ACTH) in the tumor tissues was 0.2%, being extraordinarily lower than in the pituitary tissues (23%). Gel chromatography of the tumor tissue showed large molecular weight forms of Ir-ACTH, which seem to result from abnormal processing of proopiomelanocortin, and are responsible for the lower levels of Bio-ACTH compared to Ir-ACTH. The MtT SA5 tumor is suggested to secrete ACTH-related peptides which induce pronounced adrenal enlargement with little or no stimulation of glucocorticoid production.
authors.forename: H
authors.initials: H
authors.lastname: Mori
authors.forename: S
authors.initials: S
authors.lastname: Makino
authors.forename: S
authors.initials: S
authors.lastname: Iida
authors.forename: K
authors.initials: K
authors.lastname: Moriwaki
authors.forename: D
authors.initials: D
authors.lastname: Takatsuka
authors.forename: K
authors.initials: K
authors.lastname: Odaguchi
authors.forename: Y
authors.initials: Y
authors.lastname: Hayashi
authors.forename: K
authors.initials: K
authors.lastname: Matsumoto
mesh_terms: D000311:Adrenal Glands / Q000473:pathology / Q000503:physiopathology*; D000324:Adrenocorticotropic Hormone / Q000097:blood / Q000378:metabolism; D000818:Animals; D001835:Body Weight; D002460:Cell Line; D003345:Corticosterone / Q000097:blood; D005260:Female; D013006:Growth Hormone / Q000378:metabolism; D006651:Histocytochemistry; D006965:Hyperplasia / Q000473:pathology; D007016:Hypophysectomy; D007124:Immunoenzyme Techniques; D009929:Organ Size; D010911:Pituitary Neoplasms / Q000378:metabolism*; D011388:Prolactin / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D000324:Adrenocorticotropic Hormone; D011388:Prolactin; D013006:Growth Hormone; D003345:Corticosterone