Structural Changes in the Suprarenal Gland of the Mouse During Pregnancy

Abstract

ABSTRACT In the mouse there is no correlation between body weight, body length, and the size of the suprarenal gland. The size of this gland is not always indicative of its functional activity. Unilateral ovariotomy has no effect on the functional activity of the suprarenal gland. During pregnancy the gland becomes reduced in area. The hypertrophy of the zona glomerulosa occurs during pregnancy and at the 17 mm. stage it reaches the maximal secretory activity. Observations on the hypertrophy of the zona fasciculata are in agreement with those of other workers. This hypertrophy may be caused by either an enlargement of cells or an increase of their number. In the latter case it is due to the appearance of a new zone, zona gestationis. This zone reaches its maximal activity at about 17 mm., and at this stage so-called siderophile bodies (secretory granules) are visible in great numbers. Zona reticularis degenerates rapidly at an early period (before formation of placenta) of pregnancy, and at the middle of pregnancy the site of this zone is occupied by vacuoles. The hypertrophy of the medulla occurs at the closing period of pregnancy. Mitotic figures were observed in every zone except zona reticularis at an early period of pregnancy. The secretory activity of this gland increases slowly and reaches its maximum at about the third quarter of pregnancy, followed by a partial decrease during the last quarter.