STEREOLOGY OF HUMAN FETAL ADRENAL-MEDULLA

Stereological studies were performed on 27 pairs of adrenal glands of human fetuses (9-38 weeks of intra-uterine development). Medullary chr omaffin cells were identified by immunostaining for chromogranin-A. Th e volume of adrenal medulla, average cell volume, and the number of ch romaffin cells were calculated. The volume of adrenal medulla increase d slowly up to the 20th week and afterwards it enlarged rapidly to the 31st week of the fetal period. A gradual, linear increase in the numb er of chromaffin cells of developing adrenal medulla was observed duri ng the studied period. On the contrary, the average volume of the adre nal medullary cells remained quite constant until the 17th week of the development. Afterwards, a gradual, linear increase in the cell volum e was observed until the 31st week, reaching a plateau by the end of i ntra-uterine development.