Stereology of human fetal adrenal medulla

Abstract

Stereological studies were performed on 27 pairs of adrenal glands of human fetuses (9-38 weeks of intra-uterine development). Medullary chrornaffin cells were identified by irnrnunostaining for chromogranin-A. The volume of adrenal rnedulla, average cell volurne, and the number of chrornaffin cells were calculated. The volume of adrenal medulla increased slowly up to the 20th week and afterwards it enlarged rapidly to the 3 1 st week of the fetal period. A gradual, linear increase in the number of chromaffin cells of developing adrenal rnedulla was observed during the studied period. On the contrary, the average volurne of the adrenal medullary cells rernained quite constant until the 17th week of the development. Afterwards, a gradual, linear increase in the cell volume was observed until the 31 st week, reaching a plateau by the end of intra-uterine developrnent.