The effect of phytohemagglutinin on the induction of pulmonary carcinoma in rats by methylcholanthrene
Liu, J.L.
Zhonghua Zhong Liu Za Zhi 5(2): 94-97
1983
ISSN/ISBN: 0253-3766 PMID: 6872842 Document Number: 197117
Phytohemagglutinin (PHA) has been considered as a nonspecific stimulator for proliferation of thymus-dependent lymphocytes. It can increase cellular immunity, which is generally regarded to be important in anti-tumor immune reaction. In foreign literature, reports about the effect of PHA on transplantable tumors in animals are controversial. This article reports the effect of PHA on the chemical carcinogenesis of lung cancer in rats. Well-differentiated squamous cell carcinoma of lung was induced by repeated intratracheal instillation of 3-methylcholanthrene (MCA). PHA (2 mg/0.4 ml per rat) was given in 6 doses. Each dose was given 24 h prior to the instillation of MCA. By the end of the 10th mo., the incidence of pulmonary carcinoma in rats given with MCA + PHA was 68.1% vs. 45.2% in the control rats with MCA alone (P < 0.05). The latent period of the MCA + PHA group was also markedly shortened. PHA had a marked enhancing effect on the development of pulmonary carcinoma in rats opposite to the expected inhibiting effect.