Effect of hypophysectomy on the volume and ultrastructure of zona glomerulosa in rat adrenal.

The zona glomerulosa of the rat has been examined at various times after hypophysectomy. There is no detectable change in the zona glomerulosa at 2 days after hypophysectomy. However by 7 days, the width of the glomerulosa became significantly larger in spite of an absolute decrease in the volume of the zone. No alternations in ultrastructure were discernible at this time in the glomerulosa, although giant mitochondria were seen in adjacent zona fasciculata cells. By 30 days there was a much wider zona glomerulosa and a restoration of the volume of the zone to that found in controls. Many zona glomerulosa cells were hypertrophic. The Golgi apparatus was enlarged and many vesicles were associated with peripheral cisternae. A few intramitochondrial tubules were observed in some mitochondria of the zona glomerulosa at 30 days.