Tumor Cell Cytolysis Mediated by Valorphin, an Opioid-Like Fragment of Hemoglobin β-Chain

Blishchenko, E. Yu., O. A. Mernenko, I. I. Mirkina, D. K. Satpaev, V. S. Ivanov, L. D. Tchikin, A. G. Ostrovsky, A. A. Karelin and V. T. Ivanov. Tumor cell cytolysis mediated by valorphin, an opioid-like fragment of hemoglobin β-chain. Peptides 18(1) 79–85, 1997.—Valorphin, an endogenous opioid-like hemoglobin fragment, is cytotoxic for L929 and K562 tumor cells in 10 −7–10 −13 M concentration range. Because cytolytic effects induced by valorphin in K562 cells are inhibited by naloxone, opioid receptors should be involved in induction of valorphin-mediated tumor cell death. Three distinct cytolytic processes, differing in the onset time and the development time, take place with K562 cells within 10–18 h of incubation with valorphin. All three processes are not associated with apoptotic mechanism of cell death.