THE EFFECT OF ZYMOSAN-INDUCED GENERALIZED INFLAMMATION ON TUMOR-GROWTH IN A RAT RENAL-CELL CARCINOMA MODEL

We investigated the inhibition of tumour growth by induction of a gene ralized inflammatory response. 45 Lewis rats were randomly divided in three groups. A rat renal cell carcinoma was transplanted subcutaneous ly on day one in group I and group II. When the tumour became measurab le on day 16, a generalized inflammation was induced by intraperitonea l injection with a suspension of zymosan and paraffin in group I and i n group III, consisting of non-tumour bearing animals. Group II was in oculated with paraffin only. Seven and 14 days following intraperitone al injection two rats out both group I and group II were sacrificed in order to obtain tumour biopsies at different stages of a generalized inflammatory response. Spontaneous mortality occurred twice in group I II, consisting of non-tumour bearing animals. On day 37 all surviving rats were killed. Microscopical examination was carried out on all tum ours and on lungs, liver, spleen and kidneys. A generalized inflammati on response was confirmed in group I and III through biologic and micr oscopic parameters. After a zymosan induced generalized inflammation r esponse in the rat, tumour growth rate was significantly lower compare d with paraffin treated animals.