Acute injections of opiate peptides into the rat cerebral ventricle: A macrophage-like cellular response

Saland, L.C.; Epps, Dennis E. Van; Ortiz, Evelina; Samora, A.

doi:10.1016/0361-9230(83)90150-8

Cited by 27 publications

(12 citation statements)

References 27 publications

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“…This may indicate that met-enkephalin produced at sites of inflammation promotes the influx of immune cells. In agreement with this concept are the recent findings by Saland and co-workers (27), that endogenous opoids such as a-and fl-endorphin and met-enkephalin, administered to the lateral ventricle of rats, caused an influx of leukocytes.…”

Section: Detection Of Met-enkephalin Immunoreactive Cells In Vivosupporting

confidence: 77%

Differential processing of proenkephalin-A by human peripheral blood monocytes and T lymphocytes.

Kuis

Villiger²,

Leser³

et al. 1991

J. Clin. Invest.

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Human peripheral blood mononuclear cells are analyzed for preproenkephalin gene expression and peptide processing.Met-enkephalin immunoreactivity as detected with a specific antiserum is found in the cytoplasm of monocytes but not in T lymphocytes. Secretion of met-enkephalin was analyzed with an RIA that is specific for the met-enkephalin pentapeptide. Unfractionated PBMC spontaneously released 40 pg/ml met-enkephalin and this increased two-to fourfold after stimulation with PHA. Lower levels (< 100 pg/ml) of met-enkephalin were detected in supernatants from purified T cells that were activated with PHA and IL-2. In contrast, stimulation of purified monocytes with LPS or PMA resulted in the release of up to 600 pg/ml of the processed peptide. To examine whether T cells can produce met-enkephalin precursor peptides, T cell conditioned media were treated with trypsin and carboxypeptidase-B, which is known to release met-enkephalin from the propeptide. This increased levels of met-enkephalin to 400 pg/ ml, indicating that lymphocytes secrete the propeptide but do not process it to met-enkephalin. The 1.4-kb preproenkephalin mRNA is detected in activated blood mononuclear cells and in purified monocytes and T cells.To determine whether monocytes or lymphocytes express met-enkephalin in vivo, lymphoid tissues were analyzed by immunohistochemistry. In human spleen tissue, positive cells were found in the red pulp but not in the follicles, which is also consistent with met-enkephalin expression in monocytes.In summary, these results show that human peripheral blood mononuclear cells express preproenkephalin mRNA and that monocytes, but not T cells, process the propeptide to metenkephalin. (J. Clin. Invest. 1991. 88:817-824.)

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Section: Detection Of Met-enkephalin Immunoreactive Cells In Vivosupporting

confidence: 77%

Differential processing of proenkephalin-A by human peripheral blood monocytes and T lymphocytes.

Kuis

Villiger²,

Leser³

et al. 1991

J. Clin. Invest.

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“…Saland et al [75,76] reported a macro phage-like cellular response after injection of p-End in pharmacological concentrations (leading to altered behavior) into the cerebral ventricle of the rat. In vitro this group used a test system that indicated chemotaxis of hu man PMNs and monocytes to P-End and Met-Enk [95, 95a], Contrary to this conclu sion, using a more precise test system (Zigmond chamber), we confirmed that this does not occur with physiological concentrations.…”

Section: Leukocytes/monocytesmentioning

confidence: 99%

Β-Endorphin Modulates Immune Functions

Fischer¹,

Falke²

1984

Psychother Psychosom

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“…In sheep the infusion of MET-ENK into the afferent lymphatics of popliteal nodes caused lymphocyte migrations from the node into the efferent lymph (16). When MET-ENK was injected into the cerebral ventricles of rodents both lymphocytes and macrophages were recruited to the injection site (14). Other studies carried out in vitro have confirmed that MET-ENK is chemotactic for isolated human peripheral blood T cells (11), monocytes (13,14), and polymorphonuclear leukocytes (17).…”

Section: Introductionmentioning

confidence: 87%

“…Studies in rodent and large animal models have shown that the opioid pentapeptide methionine-enkephalin (MET-ENK)' enhances lymphocyte trafficking (7,(11)(12)(13), stimulates transendothelial migrations, and causes the redistribution of circulating leukocytes ( 14,15 ). In sheep the infusion of MET-ENK into the afferent lymphatics of popliteal nodes caused lymphocyte migrations from the node into the efferent lymph (16).…”

Section: Introductionmentioning

confidence: 99%

“…When MET-ENK was injected into the cerebral ventricles of rodents both lymphocytes and macrophages were recruited to the injection site (14). Other studies carried out in vitro have confirmed that MET-ENK is chemotactic for isolated human peripheral blood T cells (11), monocytes (13,14), and polymorphonuclear leukocytes (17). Opioid peptides, like other leukocyte chemoattractants, have been shown to trigger a number of biochemical and cellular events including transmembrane signaling (18), cell flattening, membrane spreading, and pseudopod extension (19).…”

Section: Introductionmentioning

confidence: 99%

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Enkephalins stimulate leukemia cell migration and surface expression of CD9.

Heagy

Duca²,

Finberg³

1995

J. Clin. Invest.

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Opioid peptides have been implicated in the regulation of tumor growth and biology; however, little attention has been given to the mechanisms that are involved. In this study we show that physiological concentrations of the endogenous opioid neuropeptide methionine-enkephalin (MET-ENK) and the synthetic enkephalins D-Ala2,Me-Phe4,Gly(ol)' and D-Ala2,D-Leu5 are stimulants for the in vitro migration of pre-B acute lymphoblastoid leukemia (ALL) cells. Activation of the human pre-B ALL cell lines NALM 6 and LAZ 221 with MET-ENK resulted in both an increase in their migration and an augmentation in the surface expression of the leukemia cell marker CD9. The opiate receptor antagonist naloxone reversed these enkephalin-induced effects on the leukemia cells. When the pre-B ALL cells were preincubated with an anti-CD9 mAb before challenge with MET-ENK their migration to the enkephalin was markedly reduced. These studies show that endogenous and synthetic opioid peptides are stimulants for pre-B ALL cell migration and suggest that CD9 is important in the regulation of leukemia cell motility. (J. Clin. Invest. 1995. 96:1366-1374

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Acute injections of opiate peptides into the rat cerebral ventricle: A macrophage-like cellular response

Cited by 27 publications

References 27 publications

Differential processing of proenkephalin-A by human peripheral blood monocytes and T lymphocytes.

Differential processing of proenkephalin-A by human peripheral blood monocytes and T lymphocytes.

Β-Endorphin Modulates Immune Functions

Enkephalins stimulate leukemia cell migration and surface expression of CD9.

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