COMPARATIVE STEREOLOGICAL STUDIES ON ZONATION AND CELLULAR COMPOSITION OF ADRENAL-GLANDS OF NORMAL AND ANENCEPHALIC HUMAN FETUSES .2. CELLULAR COMPOSITION OF THE GLAND

In our previous paper (Bocian-Sobkowska et al., 1997) we demonstrated a striking difference in development of zonation in adrenals of normal and anencephalic human fetuses. The purpose of the present study was to characterize, by means of stereology, the cellular composition of d eveloping adrenals in the same case. Studies were performed on 11 pair s of adrenal glands from normal fetuses and 10 from anencephalic fetus es. In the studied period of development (24 to 39 weeks of intra-uter ine life) the average volume of cells in normal glands increased as fo llows: zona glomerulosa (ZG) from 355 to 870 mu m(3); zona fasciculata (ZF) from 779 to 1200 mu m(3) fetal zone (FZ) from 2004 to 2380 mu m( 3); and medulla (M) from 600 to 970 mu m(3). In anencephalic fetuses, the appropriate values were: ZG - 380-680 mu m(3); ZF - 460-680 mu m(3 ) FZ - 1820-1680 mu m(3); and M - 870-1400 mu m(3). At the end of the studied period the number of ZG cells in normal fetuses was two fold h igher than in anencephalics, ZF cells - 6-fold and in FZ - 5-fold high er, while in the M the number of cells was nearly equal in both groups . During the whole investigated period of intra-uterine development th e total number of adrenocortical cells in normal glands increased ca 2 .5-fold, while in anencephalic glands only ca 0.5-fold, reaching at th e end ca 40% of normal value. In both normal and anencephalic adrenals the number of ZG and M cells was highly correlated with ZG/M cell rat io, being slightly higher in normal glands. No such relation was demon strated for cells of the remaining adrenocortical zones.