Fetal and Postnatal Development of the Adrenal Glands in Macaca mulatta1

Abstract

The inner four-fifths of the fetal and newborn adrenal cortex

Morphological adrenarche in rhesus macaques: development of the zona reticularis is concurrent with fetal zone regression in the early neonatal period

“…Based on morphology and a general lack of CYP21A2 expression in the FZ compared with the ZR, the cells of these two adrenal zones exhibit different steroidogenic phenotypes. The expression of CYP21A2 in the DB-ZR and its resemblance to the ZR therefore supports the view expressed by McNulty and colleagues based on morphology alone (McNulty et al 1981) that the ZR develops from their so-called 'dense band'. ZR development and FZ regression are also clearly coincident events in the rhesus (Fig.…”

“…Despite observations suggesting human FZ regression occurred by massive cellular collapse involving necrosis (as reviewed (Lanman 1953)), it is more likely that involution of the FZ is gradual (Scammon 1926, Benner 1940, Sucheston & Cannon 1968. In agreement with the latter reports, McNulty et al (1981) noted a gradual reduction in FZ width without necrosis or signs of involution in the neonatal rhesus adrenal cortex. Using the markers b5 and CYP21A2, in addition to morphology, our data confirm that the rhesus FZ undergoes a progressive, if more rapid, regression post-natally than that seen in humans.…”

“…However, immunohistochemical (IHC) studies confirm that the rhesus ZR has the functional capacity for androgen synthesis (Mapes et al 1999), similar to the human ZR . As in humans, rhesus adrenal development is also associated with regression of an equally distinct fetal zone (FZ) during the neonatal period (McNulty et al 1981). Given the parallels in fetal and adult adrenocortical differentiation in both species, it seems that the rhesus macaque must experience an adrenarche.…”

“…The immediate post partum and early neonatal period is a particularly dynamic one where differentiation of the adrenal cortex of rhesus macaques is concerned (McNulty et al 1981), but it has not been extensively investigated in this species with respect to functional differentiation. Therefore, it was anticipated that better defining the cellular differentiation and zonation of the rhesus adrenal cortex during the early neonatal period would provide insight into ZR development, the event associated with adrenarche, in humans and nonhuman primates.…”

Activin and inhibin in the human adrenal gland. Regulation and differential effects in fetal and adult cells.

“…The adult zonae glomerulosa, fasciculata, and reticularis are formed from the definitive cortex with an undefined contribution from maturational changes in the fetal zone (29). A primate fetal zone transformation to form part of the adult cortex has been proposed previously (30,31 ). The ACTH-induced shift from primarily DHAS production to increased cortisol production in the fetal zone is analogous to the shift in steroidogenesis that occurs postnatally.…”