Abstract
Pituitary weights were already increased in SHR at the young stage (8weeks of age) compared with WK. The weights of anterior lobes were also increased at the age of 4 months. This increase in weight appeared to have a functional significance as proved by the increased 3H-lysine incorporation into the pituitary. As the prevention of the development of hypertension by apresoline treatment or by splanchnicotomy had no effect on the increased lysine-incorporation, the acceleration of such a metabolism did not seem to be the secondary phenomenon to hypertension, but was supposed to be a primary alteration in SHR. ACTH content in the pituitary was increased in pretreatment of dexamethasone, ACTH content was rather decreased in SHR. 4-month-old SHRSP compared with the age-matched WK. After the acute pretreatment of dexamethasone, ACTH content was rather decreased in SHR. This finding suggested one possibility that dexamethasone did not efficiently block ACTH secretion from the pituitary in SHR.
