EFFECTS OF CYPROTERONE-ACETATE IN C57BL 10J MICE/

Male and female C57BL/10J mice were fed 0 or 800 ppm cyproterone aceta te (CPA) in the diet for 13 weeks. 1 Body weight was reduced (P>0.001 at 13 weeks) by approximately 33%. 2 Seminal vesicle weights were redu ced (P>0.001) and showed histological atrophy, changes consistent with the anti-androgenic activity of the compound. 3 Liver weights were in creased (P>0.001) by +90% of control mean weights; hepatocyte hypertro phy and increased fat and glycogen were seen by light microscopy, and hyperplasia of smooth endoplasmic reticulin by transmission electron m icroscopy. 4 Assessment of liver mixed function oxidase activity demon strated induction of cytochrome P450 enzymes, and increased isozyme 2B 1/2 in males and 3A1 in both sexes was confirmed by immunohistochemica l staining of liver sections. 5 An increase in bromodeoxyuridine (BrdU ) labelling index of the liver was seen in females only. 6 This study is the first in a programme of work with CPA designed to investigate t he effects of the compound in mice. It demonstrates that the hepatic e ffects of the compound which have been described in the rat also occur in mice.