Cancer Research Institute, Slovak Academy of Sciences, Špitálská 21, 812 32 Bratislava, Czechoslovakia
Cyclocytidine (cC) as an analog of clinically used antileukemic drug arabinosylcytosine is resistant towards the cytidindeaminase activity. This prompted us to evaluate its activity in preclinical testing in non — leukemic cells. The effect of cC on Zajdela hepatoma cells in vivo was tested in our experiments. It was shown that cC increased the medium survival time (MST) of Zajdela hepatoma bearing rats in a dose-dependent manner. This increase was not significant-at dose of 250 mg per kg of body weight but was highly significant (0.005) at dose of 500 mg per kg of body weight. The MST increase was 48 % and 39 %, respectively. cC did not show and adverse effect on hetapal functions of healthy rats, rats weight gain and on liver regeneration activity after partial hepatectomy. A marginal increase effect of liver weight was seen at healthy rats after cC administration. cC administration did not resulted in an increase of cytochrom oxidase activity in hepatal mitochondria of rats without or after partial hepatectomy, or in cytochrom a,aa and b concentration but it resulted in a significant increase of cytochrom c,C concentration.These result lead us to to hypothesize that cC may highly influence some bioenergetic functions of hepatocytes during therapy.
Cyclocytidine and its effect on Zajdela hepatoma cells
