Tumour pH under induced hyperglycemia and efficacy of chemotherapy

Blood glucose and insulin content, as well as tumour pH, were evaluated under induced hyperglycemia in Wistar or strain IOP rats bearing Guerin carcinoma. The average tumour pH decreased to 5.2-5.4, and could be maintained at this level for at least 24 hr. It was demonstrated that the antitumour effect of thiophosphamide was greatly enhanced under conditions of low tumour pH. The length of survival of rats bearing a Guerin carcinoma increased 6-fold when thiophosphamide was injected during the induced hyperglycemia.