[The inhibitory effect of the synthetic leu-enkephalin analog dalargin on carcinogenesis].

Dalargin, an opioid peptide (Tyr-D-Ala-Gly-Phe-Leu-Arg), was shown to significantly inhibit the carcinogenic effect of 50 mg/kg body weight nitrosomethylurea given as single i. v. infection. The treatment was followed by an increase in the tumor latency period. Moreover, the overall incidence of tumors decreased by 20% whereas that of malignant neoplasms and breast adenocarcinoma--by 33 and 27%, respectively. Pronounced inhibitory effect of dalargin on hematopoietic tumor induction was identified, too.