AGING ALTERS ZONATION IN THE ADRENAL-CORTEX OF MEN

Whereas aging has been shown to be associated with striking reductions in circulating levels of adrenal androgens in humans, the alteration in adrenal function that occurs in aging has not been identified We so ught to determine if there are changes in the zonation of the adrenal in aging men by performing histomorphologic analyses of adrenal specim ens that had been obtained at autopsy following sudden death due to tr auma. We evaluated adrenals from 21 young men (20-29 yrs) and 12 older men (54-90 yrs); inclusion criteria required the presence of medullar y tissue in the specimen and fixation within the first 24 hrs postmort em. Sections stained with WE were examined microscopically and areas o f the cortex that included adjacent medullary tissue were chosen for q uantitative evaluation by use of a computerized image analysis system. The average width (arbitrary units, pixels) of the zona reticularis a nd that of the combined zonae fasciculata/glomerulosa were determined from sections stained for reticulum fibers. The zona reticularis repre sented 37.1 +/- 1.9% of the total cortical width in the young men, whi ch was significantly greater than that of the older men (27.1 +/- 3.3% , P = 0.0082). The zona fasciculata/glomerulosa to zona reticularis ra tio in the young men (1.84 +/- 0.15) was significantly less that that of the older men (3.29 +/- 0.47, P = 0.0011). There was no significant difference in the total width of the cortex in young compared to olde r men. These data suggest that aging results in alterations within the cortex of the adrenals in men such that there is a reduction in the s ize of the zona reticularis and a relative increase in the outer corti cal zones. A reduced mass of the zona reticularis could be responsible for the diminished production of dehydroepiandrosterone and dehydroep iandrosterone sulfate that occurs during aging.