Abstract
Fetal adrenal weight increased with the progress of gestation, especially after the 7th month of gestation. The ratio of adrenal weight to body weight decreased with the progress of gestation. The cells of zona glomerulosa and zona fasciculata appeared in the 4th month and those of the zona reticularis in the 7th month of gestation. Fetal zone-like cortical tissue appeared beneath the inner fascicular zone in the 4th month. Sudanophilic lipid droplets were found in considerable abundance in both zona glomerulosa and zona fasciculata in the 4th month. They graduall increased in size in the following order: zona reticularis<zona fasciculata <zona glomerulosa. Fetal serum 11-01-ICS level increased with the progress of gestation, especially after the 8th month of gestation.
The secretion and biosynthesis of the adrenocortical hormones by the fetal adrenal cortex began at 4-5 months of gestation. The fetal pituitary-adrenocortical function became maximum at the end of gestation. It was suggested that hyperfunction of the fetal pituitary-adrenocortical system near term might play an important role in the initiation of parturition in the cow.
