Enhancement of host resistance to viral and tumor challenge by treatment with methionine-enkephalin.
Host resistance to disease is dependent upon a number of factors. Recent evidence indicates that natural killer (NK) cells play an important role in resistance to both neoplastic and virally induced disease. Treatment of C57Bl/6 mice with methionine-enkephalin (1, 3, 10, or 30 mg/kg body weight) results in significant increases in NK activity of splenic lymphocytes 20 hours after injection of the enkephalin. Enkephalin treatment also enhances host resistance. The short-term survival of A/J female mice after HSV-2 infection was significantly increased by daily subcutaneous injections (3 mg/kg body weight) of methionine-enkephalin. Similarly, daily doses of 50 micrograms of methionine-enkephalin for 7 to 14 days inhibit the local subcutaneous tumor growth of B15 melanoma in C57Bl/6 mice.
D000276:Adjuvants, Immunologic; D000818:Animals; D004744:Enkephalin, Methionine / Q000276:immunology / Q000494:pharmacology*; D005260:Female; D006561:Herpes Simplex / Q000276:immunology* / Q000401:mortality; D007113:Immunity, Innate / Q000187:drug effects*; D007694:Killer Cells, Natural / Q000187:drug effects / Q000276:immunology*; D008546:Melanoma, Experimental / Q000276:immunology* / Q000473:pathology; D051379:Mice; D008805:Mice, Inbred A; D008810:Mice, Inbred C57BL; D009270:Naloxone / Q000494:pharmacology
D000276:Adjuvants, Immunologic; D009270:Naloxone; D004744:Enkephalin, Methionine