engleski

Heat Potentiated the Efect of Antitumour Drugs

Antitumour effect of some cytostatlc drugs can be increased when combined with heat treatment. Heat chemosensitivity of tumour cells is strongly dependent on the time interval between drug injection and heat appllcation. The aim of this study was to use a mouse tumour model to determine the optimum application of these treatments. A C3H mouse mammary carcinoma anaplastic mammary carcinoma of CBA mice were used. Tumour cells were implanted into the right rear foot of male/female mice. Ali treatments were applied when tumour reached the size of approximately 200 mm3. The applied drugs (cispiatin, ifosphamide, cyciophosphamide, etoposide) were prepared fresh for each treatment and were given intraperitoneally into mice at a constant injection volume of a 0.02 ml/g body weight For the hyperthermia treatment non-anaesthetized mice were restrained in lucite jigs and their tumour-bearing legs were then locally heated by immersing the tumour-bearing foot in a water bath set at 0.2 C above the required tumours temperature. Tumour response was assessed as the tumour growth time (TGT; the time taken for tumours to reach 5 times their treatment volume). The obtained results have shown that heat enhances cis-platinum (CisDDP) effect when cisDDP was applied before heat. The highest effect was achieved when cisDDP was given 15 min before heat application. If ifosphamide was combined with heat additive antitumour effect was achieved when ifosphamide was given both before and after heat. But synergistic antitumour effect was obtained when ifosphamide was given 15 min before heat. Similar results were obtained when cyclophosphamide was comnbined with heat, but again the best antitumour effect was if drug was given immediately before heat. The combined treatment of etoposide (VP16) and hyperthermia increases antitumour effect of vP16 only when it was given 48 or 72 hours before heat. Hyperthermia enhances antitumour effect of cisplatin, ifosphamide and cyclophosphamide. This effect is time-dependent and dose-dependent.

heat; cis-platin; ifosphamide; cyclophosphamide

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