The effect of bilateral adrenalectomy on the nucleus arcuatus-hypophysis and the circumventricular organs of Balb mice.

Three days following bilateral adrenalectomy the following findings were revealed in the hypothalamus-hypophysis and circum-ventricular organs of Balb mice: considerable enlargement of neuronal perikarya and nuclei in the nucleus arcuatus of the hypothalamus. Amitotic divisions were frequent in neurons and glial cells. Mitoses were also sporadically encountered. The pars distalis of the hypophysis showed typical post-adrenalectomy changes. In addition, enlargement of the so-called pars rostralis was observed. This part and the pars intermedia showed signs of enhanced secretion. The subfornical organ of the adrenalectomized animals was much smaller than in the controls. The subcommissural organ and pineal gland, on the contrary, were large and apparently actively secreting.