[Effect of intrahippocampal microinjection of enkephalin on cellular immune function and brain IL-1 alpha gene expression in rat].
The effect of intrahippocampal microinjection of enkephalin on cellular immune function and hippocampal IL-1 alpha gene expression was studied in rats. The results showed that: (1) The proliferation activity of splenic lymphocytes stimulated by Con A was significantly increased with microinjection of Leu-enkephalin 1 microliter (18 mmol/L) or Met-enkephalin 1 microliter (18 mmol/L) into bilateral hippocampus, but was inhibited by Lipopolysaccharide 1 microliter (50 ng/microliter). The proliferative response of splenic lymphocytes to Leu-enkephalin still persisted after bilateral adrenalectomy. Low doses of Leu- or Met-enkephalin (10(-10), 10(-11) mol/L) were also capable of causing proliferative activity of the Con A- stimulated cultured splenic lymphocytes in vitro. (2) Using RT-PCR technique, IL-1 alpha gene expression was detected in hippocampus 90 min after bilateral intrahippocampal injection of LPS. The LPS-induced IL-1 alpha gene expression in hippocampus could no longer be detected 30 min after microinjection of Met- or Leu-enkephalin into hippocampus. The above results suggested that intrahippocampal enkephalin might play an important role in neuro-immunomodulation by enhancing the inhibition of IL-1 alpha gene expression in hippocampal formation.
Wang
A J
AJ
Research Center of Experimental Medicine, Tongji Medical University, Wuhan.
Yang
Y Z
YZ
Wu
Y M
YM
Xie
H
H
Hu
M X
MX
Gao
N
N
Hong
J
J
Sun
C L
CL
D000315:Adrenalectomy; D000818:Animals; D002455:Cell Division; D004743:Enkephalin, Leucine / Q000494:pharmacology*; D004744:Enkephalin, Methionine / Q000494:pharmacology*; D005260:Female; D015870:Gene Expression; D006624:Hippocampus / Q000502:physiology*; D007375:Interleukin-1 / Q000096:biosynthesis*; D008297:Male; D008845:Microinjections; D051381:Rats; D017208:Rats, Wistar; D013601:T-Lymphocytes / Q000276:immunology*
D007375:Interleukin-1; D004744:Enkephalin, Methionine; D004743:Enkephalin, Leucine