The effect of indomethacin on food and water intake, motor activity and survival in tumour-bearing rats.

This investigation has addressed the question whether food and water intake, motor activity and tumour growth are influenced by indomethacin in experimental cancer. Growing rats implanted with a methylcholanthrene-induced sarcoma were studied in metabolic cages connected to a computer. Food intake, water consumption and motor activity were continuously recorded over 30 days following tumour implantation. Treated tumour-bearing animals received indomethacin 1.0 mg/kg per day in drinking water. Food intake declined early in untreated tumour-bearing animals, but water intake was not affected. Motor activity decreased in untreated tumour-bearing animals from days 16-17 onward. Indomethacin treatment prolonged survival and 40% of these tumour-bearers were 'complete responders'. In some animals tumour growth was only marginally affected, but survival was still significantly improved ('partial responders'). Food intake was significantly improved in complete responders. Thus this positive effect seen in complete responders was secondary to less active tumour growth. Motor activity was also significantly higher in responders compared with non-responders.