Generalized Adrenocortical Atrophy in Hypophysectomized Dogs and Correlated Functional Studies

Abstract

Structural changes of the adrenal glands and the state of both organic and inorganic metabolism were studied in hypophysectomized dogs. Use of a serial section technic revealed the total absence of pituitary tissue in 14 animals and the presence of a microscopic remnant of either the pars distalis or pars tuberalis in 7 dogs. Functionally, and with regard to the structure of the adrenal glands, the 2 groups were indistinguishable. The adrenal glands constantly exhibited wt. reduction and generalized cortical atrophy. Although the zona reticularis and inner zona fasciculata were affected earliest, most severely, and eventually appeared to undergo total atrophy, nevertheless, the zona glomerulosa also became atrophic, as evidenced by reduction in cell size, narrowing of cell columns, reduction of cytoplasmic vacuolization, diminished sudanophilia, and an increase in connective tissue, especially prominent in the most advanced states. In no instance did the outer zona fasciculata show a total atrophy. Even in the most advanced stages of atrophy, the surviving cortical tissue consisted of remnants of both the zona glomerulosa and the outer zona fasciculata; these showed comparable sudanophilia. These animals manifested disturbed carbohydrate and protein metabolism, reduced renal functions, but their ability to conserve Na during severe prolonged salt restriction was unimpaired and the renal mechanism for excretion of intravenously administered K salts was essentially normal. However, the ability to excrete an orally administered water load was severely impaired. Conclusions the structural integrity of all adrenal cortical cells depends upon the trophic influence of the anterior pituitary. However, certain cells of the zona glomerulosa and outer fasciculata, although becoming atrophic, can survive without this trophic influence. No functional ability or disability of the hypophysectomized dog can be assigned to any specific cortical layer.