Morphometric study of the human suprarenal gland in the first postnatal year

The aim of present, study was to describe adrenal volume, volumes of adrenocortical zones, and stroma volume in 40 adrenals obtained from children between 1st and 370th day during autopsy. The postnatal decrease in adrenal volume was caused mainly by rapid fall of fetal zone (FZ) volume (from 70 to 3% of total adrenal volume) that can be divided into two phases: rapid phase (from birth to the end of the second week) and a slow phase from the 3rd week on. Involution was accompanied by increase of zona glomerulosa (ZG) (from l0 to 25% of total adrenal volume), zona fasciculata ZF (from 10 to 38%) and zona reticularis (ZR), volume from 1 to 23%). During the whole investigated period the volume of medulla remained constant. The volume fraction of stroma (connective tissue and blood vessels) was highest at the beginning of the first postnatal week and then decreased rapidly at the end of the 2nd week, with the most pronounced changes in the fetal zone and medulla. Performed present stereological study confirms opinion that hemorrhagic mechanisms are involved in the involution process of the human fetal zone

Comparative stereological study on zonation and cellular composition of adrenal glands of normal and anencephalic human fetuses. l. Zonation of the gland

Comparative stereological studies were performed on zonation of adrenal glands in 10 anencephalic and 11 normal fetuses, aged between 24 and 39 postovulatory weeks. The development of adrenal fetal zone (FZ) is the main factor responsible for normal adrenal gland growth during the intra-uterine life. At the end of fetal '3e riod volume of this zone attains over 8200 mm and constitutes 69-70% of the total gland volume, while respective values for zona glomerulosa (ZG), zona fasciculata (ZF) and medulla IM' are 1665 mm3 (14%) 833 mm3 (7%) and 1071 mm (9%). These data were in striking contrast with those found in adrenals of anencephalic fetuses, in which volume of the gland attained only ca 35% of that in normal fetuses. In the oldest anencephalic fetus studied (39 weeks) the volume of the fetal zone was 962 mm3 (ca 8-folds lower than in normal fetus) comprising only 25% of the total gland volume. For the remaining zones the values were: ZG - 1501 mm3 (ca 90% of the normal value and 39% of the total gland volume); ZF - 770 mm3 (ca 92% and 20% respectively), and M - 539 mm3 (ca 50% and 14%, respective1 y). This stereological study provides the first systemic description of the development of adrenal gland of anencephalic fetuses in comparison with the normally developing gland. Moreover, evidence is given that the growth of adrenal medulla is also retarded in anencephaly while the growth of the zona glomerulosa remains rather unaffected

Comparative stereological studies on zonation and cellular composition of adrenal glands of normal and anencephalic human fetuses. II. 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 developing adrenals in the same case. Studies were performed on 11 pairs of adrenal glands from normal fetuses and 10 from anencephalic fetuses. In the studied period of development (24 to 39 weeks of intra-uterine life) the average volume of cells in normal glands increased as follows: zona glomerulosa (ZG) from 355 to 870 pm3; zona fasciculata (ZF) from 779 to 1200 pm3; fetal zone (FZ) from 2004 to 2380 pm3; and medulla (M) from 600 to 970 ym3. In anencephalic fetuses, the appropriate values were: ZG - 380-680 pn3; ZF - 460-680 pm3; FZ - 1820-1680 pm3; and M - 870-1400 pm3. At the end of the studied period the number of ZG cells in normal fetuses was two fold higher than in anencephalics, ZF cells - 6-fold and in FZ - 5-fold higher, while in the M the number of cells was nearly equal in both groups. During the whole investigated period of intra-uterine development the total number of adrenocortical cells in normal glands increased ca 2.5-fold, while in anencephalic glands only ca 0.5-fold, reaching at the 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 ratio, being slightly higher in normal glands. No such relation was demonstrated for cells of the remaining adrenocortical zones

Cytological aspects of the human adrenal cortex development in the course of intra-uterine life

Stereological studies were performed on 20 pairs of adrenal glands of human foetuses. The volume of particular adrenocortical zones, average cell volume and number of parenchymal cells were calculated. In 50 to 320 mm crown-rump length (C.-R.L.) foetuses (9-38 weeks of the intra-uterine life) an exponential increase in adrenal gland weight was found. If compared with the earlier period, the rate of increase was evidently higher beginning from the 20th week and depended mainly upon enlargement of the foetal zone, with less marked changes in the glomerulosa-fasciculata zone. The zona glomerulosa (ZG) and the outer zona fasciculata (ZF) began to delineate by the 20th week of gestation. Zona reticularis was not observed in our material. From the beginning of development, fasciculata cell volume was markedly higher than that of ZG cells and lower than foetal zona (ZX) cells. Until the 20th week of intra-uterine life the volume of glomerulosa-fasciculata zone (G-FZ) increased at a slow rate, while the rate of increase in volume of ZX was higher. After 20 weeks the rate of increase in volume of al1 adrenocortical zones was markedly higher (the same as that of the stroma). The volume of stroma in ZX markedly exceeded that in the remaining parts of the cortex. The average cell volume of ZG and ZF remained constant during the foetal period, while the average cell volume of ZX cells increased gradually from the 9th to the 20th foetal week and afterwards remained unchanged. Of interest is the fact that the percentage of ZX cells in the gland remained rather constant during the whole period of observation (about 3540% for ZX and 60-65% for ZG and ZF)

Morphometric studies on the development of the human thyroid gland. II. The late fetal life

Histological and morphometric studies were performed on 27 thyroid glands obtained from normal fetuses ranging between 23 to 40 weeks of intra-uterine life. In the thyroids the volume of gland, colloid, and stroma were calculated by means of differential pointcounting method and the height of the thyroid follicular cells was measured. Moreover, the epithelium/colloid ratio in the thyroid gland, a very sensitive parameter of stimulation of the glands by TSH, was calculated. Regarding the values of this ratio in human fetal thyroid gland, the intra-uterine development of the gland may be divided into three distinct stages. The first one, between weeks 10- 18 is characterized by massive folliculogenesis and gradual accumulation of the colloid. The second stage, between weeks 19-29 of fetal life is characterized by rather unchanged values of epithelium/colloid ratio and the size of follicles. The third stage, after the 29th week of development is characterized by a gradual increase in the epithelium/colloid ratio and a decrease in the size of follicles

Morphometric studies on the development of human thyroid gland in early fetal life

Histological and morphometric studies were performed on 30 thyroid glands obtained from normal human fetuses. Their crown-rump length (CRL) ranged from 57 to 190 mm, corresponding to the gestational age of 10 - 20 weeks. The weight of the thyroid gland increased proportionally in relation to CRL, foot length and fetus weight. The first follicles containing PAS-positive colloid were observed in the peripheral part of the thyroid gland of 57 mm CRL fetus. The number of follicles per 1 mm2 of thyroid surface section increased up to 85 mm CRL and thereafter gradually declined for the end of studied period of fetal life. The volumes (in mm3) of thyroid epithelium, colloid and stroma, beginning from 85 mm increased proportionally to the CRL while the height of epithelial cells did not change. The epithelium/colloid ratio decreased notably to 165 mm CRL and thereafter remained constant. Results of the present study suggest that the thyroid gland of human fetus approaches structural maturity in 17.5 week of gestation

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 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