CISPLATIN-INDUCED PICA BEHAVIOR IN RATS IS PREVENTED BY ANTIOXIDANTS WITH ANTIEMETIC ACTIVITY

Pica, eating of non-nutritive substances such as kaolin in rats has be en suggested as an illness response behaviour, analogous to vomiting i n species that have developed emetic reflex. We have recently demonstr ated that antioxidants-glutathione, N-(2-mercaptopropionyl)glycine (ti opronin), vitamin C and vitamin E-exert antiemetic effect against cisp latin-induced emesis in dogs. In the present study, the effect of thes e antioxidants was investigated against pica model in rats. Pretreatme nt with these agents significantly inhibited the cisplatin induced enh anced kaolin intake. However, these agents failed to exert any signifi cant improvement in the decreased food intake by cisplatin. The findin gs confirm the potential of these antioxidants as antiemetics against cancer chemotherapy induced vomiting, though they may not improve the anorexia. The experiments further support that pica in rats can be use d as a good alternative rodent model to dogs and cats particularly for preliminary and rapid screening of antiemetic agents. (C) 1997 Elsevi er Science B.V.