Enhancement of thermal damage to the microcirculation of ‘sandwich’ tumours by additional treatment

• Published in: European journal of cancer & clinical oncology Vol. 17; no. 7; pp. 781 - 795
• Main Authors: Reinhold, H.S., Van Den Berg-Blok, A.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.07.1981
• Subjects: Animals; Glucose - analogs & derivatives; Glucose - pharmacology; Hot Temperature; Microcirculation - drug effects; Misonidazole - pharmacology; Radiation-Sensitizing Agents - pharmacology; Rats; Rats, Inbred Strains; Rhabdomyosarcoma - blood supply; Sarcoma, Experimental - blood supply; Time Factors
• ISSN: 0277-5379
• DOI: 10.1016/0014-2964(81)90234-6

The effects of hyperthermia on tumour microcirculation were investigated. For this purpose, transparent tumours were grown in the ‘sandwich’ system in the dorsal skin flap of the rat (Rhabdomyosarcoma BA1112 in WAG/Rij rats). Heating was performed with air; the temperature of the cover slip overlying the tumour was kept at either 42.5° or 42°C by means of an electronic controller. Evaluation of the effect was based on microscopic observation and photographic recordings and was expressed as the proportion of tumours with intact microcirculation, i.e., the proportion of tumours not showing heat damage. The results indicate that, at 42.5°C after a latent period of about 1 hr, the microcirculation of the tumours begins to slow down. At the end of a treatment time of 180 min, about 70% of the tumours show microcirculatory damage. It appears that some time is required before the majority of the tumours show heat damage. The effect is still essentially the same at 42°C, but the damage is to a much lesser extent. When the animals received additional treatment, i.e. misonidazole, glucose or 5-thio- d -glucose, the damaging effect of the hyperthermic treatment at 42°C appeared to be increased. The effects of all combined treatments approximated the degree of inactivation obtained with 42.5°C treatment.