Quantitative electron microscopy of carcinogen-induced alterations in hepatocyte rough endoplasmic reticulum. II. Modulation of the effects of 3'MeDAB by adrenalectomy and adrenal corticosteroids.

A quantitative electron microscope study was made of the effects of bilateral adrenalectomy (ADX) and deoxycorticosterone acetate (DOCA) on the state of aggregation of hepatocyte rough ER cisternae in both untreated and 3'MeDAB-fed Leeds strain rats. Disaggregation of hepatocellular rough ER appears to be a common response of the rat liver to hepatocarcinogenic insult, while ADX and DOCA treatment are known to inhibit the chemical induction of neoplasia in this species. In untreated animals both ADX and DOCA significantly increased the mean number of cisternae per array or stack, while an even more pronounced effect was obtained from a combination of the two. The carcinogen 3'MeDAB induced a highly significant loss of aggregation, which was prevented by the combination of ADX and DOCA. In a separate experiment, a single dose of cortisone acetate was also found to partially reverse 3'MeDAB-induced rough ER disaggregation. In the rat hepatocyte, rough ER stacking or aggregation appears to be at least partially under hormonal control.