The reversal of surgically induced reticuloendothelial depression.

The function of the reticuloendothelial (RE) system may be depressed by surgical operation. As this system is an important defence mechanism against tumour growth and metastasis, it would be an advantage if this depression could be prevented by the administration of a suitable agent. The agents studied in this case were levamisole, Corynebacterium parvum (C. parvum) and glucan. As a measure of RE function a carbon clearance test was performed in rats, 1 hr after partial colectomy, animals having received pre-operative treatment with one of these substances. The results show that operation produced a significant fall in clearance (P less than 0.001). Both C. parvum and glucan were very effective in preventing any fall of clearance following operation (P less than 0.01). Both of these produced marked RE stimulation and values in animals given these agents remained above control values even after surgery. Levamisole had some effect in preventing the RE depression (P less than 0.02), but was not as effective as either C. parvum or glucan.