Quantitative histological changes in the rat hypothalamus following bilateral adrenalectomy.

Abstract

At 24 h after bilateral adrenalectomy, an increase in nuclear volume can be observed in the anterior centromedial cell group of the ventromedial nucleus; this increase is still present on the 7th day after surgery. At 48 h after operation, a gradually progressing increase in nuclear volume can be seen in the anterior medial cell group in the ventromedial nucleus and in the most orally situated cell group in the arcuate nucleus. During the first week following adrenalectomy, no nuclear volume change occurs in any of the other cell groups in the arcuate nucleus or the ventromedial nucleus, nor in any of the other hypothalamic nuclei. These findings can be interpreted as suggesting that by far the most corticosteroid-sensitive neurones are not dispersed throughout the medial basal hypothalamus, but are located in its two well-defined cell groups. Nuclear volume shrinkage can be observed in anterior ventromedial and ventral premamillary nuclei 24 h after adrenalectomy and in the supraoptic nucleus on the 7th post-operative day.