In vivo enhancement of NK cell activity with met-enkephalin and glycyl-glutamine: their possible role in the conditioned response.
These studies investigated the effect of met-enkephalin, glycyl-glutamine, and naltrexone on NK cell activity in vivo and in vitro. It was found that both met-enkephalin (which shares the amino-terminal end of beta-endorphin) and glycyl-glutamine (which reflects the carboxyl-terminal end of beta-endorphin) can enhance the NK cell activity of mice prestimulated with a low dose (1 microgram/mouse) of poly I:C. Naltrexone had no effect. In vivo prestimulation of the mice with 1 microgram poly I:C was necessary as mice which were not pretreated with poly I:C did not show enhanced NK cell activity when treated with either met-enkephalin or glycyl-glutamine. In vitro studies however indicate that the drugs when cultured together with the NK cells from mice preactivated with poly I:C did not have a direct stimulatory effect on the NK cells. These studies imply that while beta-endorphin released from the pituitary could be involved in enhancement of activated NK cells in vivo other indirect peripheral pathways might be involved. The results suggest beta-endorphin probably reacts with other accessory type cells which in turn release the mediators which are required for the stimulation of NK cells in vivo.
Ghanta
V K
VK
Department of Biology, University of Alabama, Birmingham 35294.
Rogers
C F
CF
Hsueh
C M
CM
Hiramoto
N S
NS
Soong
S J
SJ
Hiramoto
R N
RN
D000818:Animals; D003213:Conditioning, Psychological / Q000187:drug effects*; D004151:Dipeptides / Q000494:pharmacology*; D004744:Enkephalin, Methionine / Q000494:pharmacology*; D066298:In Vitro Techniques; D007694:Killer Cells, Natural / Q000187:drug effects*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009271:Naltrexone / Q000494:pharmacology; D011070:Poly I-C / Q000494:pharmacology; D013154:Spleen / Q000166:cytology / Q000187:drug effects; D013268:Stimulation, Chemical
D004151:Dipeptides; C039788:glycylglutamine; D004744:Enkephalin, Methionine; D009271:Naltrexone; D011070:Poly I-C