FUNCTIONAL PRENATAL DEVELOPMENT OF ANENCEPHALIC AND NORMAL ANTERIOR-PITUITARY GLANDS - HUMAN AND EXPERIMENTAL-ANIMALS STUDIED BY PEROXIDASE-LABELED ANTIBODY METHOD

Abstract

In order to investigate the influence of the CNS on functional differentiation of the fetal anterior pituitary gland, the pituitary gland of anencephalic and normal fetuses was studied by the peroxidase-labeled antibody method for the localization of various hormones. The only abnormality of pituitary endocrine cells in anencephaly was a marked decrease of ACTH cells. In normal development, ACTH appeared at 5 wk [the earliest hormone] and all other hormones at 13 wk. The reason for the decrease of ACTH cells in anencephaly may be a suppression at an early developmental stage. The experimental observations done in rats using MAM [methylazoxymethanol] may support this speculation. The adrenal glands of anencephalus showed atrophy of the fetal cortex which was correlated with a decrease in the number of ACTH cells. Absence of histochemical activity of alkaline phosphatase in the permanent cortex of anencephaly may indicate absence or inadequate stimulation by fetal ACTH.