Biomedical subjects

N E Falke

Publications and source records attributed to N E Falke.

5 recordsLinked to original sources

PubMed1987

Interaction of met-enkephalin with human granulocytes.

Met-enkephalin has been found to have an effect on cell shape and motility of human polymorphonuclear leukocytes (PMNs). Specific binding of tritium-labeled Met-enkephalin to the cells could not be demonstrated. There was a rapid proteolytic degradation of the peptide in the medium, followed by uptake of the labeled tyrosine. The peptidase recognizes the N-terminal sequence of various endogenous opioid peptides. The protease inhibitors bestatin and bacitracin had but little effect on the degradation of Met-Enk.

Cell Movement↗

PubMed1986

Opiate receptor mediated internalization of 125I-beta-endorphin in human polymorphonuclear leucocytes.

The early events in the interaction of (125I)-Tyr27-beta-endorphin with human polymorphonuclear leucocytes were investigated. Using ultrastructural autoradiography we found that the labeled peptide specifically bound to the plasma membrane and was internalized within two minutes of incubation at 37 degrees C. Both processes could be inhibited by unlabeled beta-endorphin or by the opiate antagonist diprenorphine. This finding was confirmed by radioreceptorassays. With longer incubation times the specific association of the labeled beta-endorphin with the cells decreased. About 10% of the tracer was degraded within 10 min of incubation as shown by gel chromatography. The morphological changes induced by 125I-beta-endorphin in the granulocytes were investigated under the microscope. The labeled peptide had the same biological effect as unlabeled beta-endorphin.

Autoradiography↗

PubMed1985

Stereospecific opiate binding in living human polymorphonuclear leucocytes.

Living human polymorphonuclear leucocytes were incubated with various opiate agonists and antagonists in radioreceptor assays. Binding of the opiate antagonists 3H-naloxone and 3H-diprenorphine and of the benzomorphan 3H-ethylketocyclazocine was found at 4 degrees C and at 37 degrees C, 3H-naloxone binding was stereospecific. Binding of the opiate agonist 3H-dihydromorphine was present at 37 degrees C but not at 4 degrees C and had a different time course as compared to the antagonists. At both temperatures no specific binding of the proteolytic stable analogue 3H-D-Ala-D-Leu-enkephalin was found. Autoradiography showed an unspecific accumulation of 3H-naloxone inside the cells and a specific localization of grains at the cell membrane.

Analgesics, Opioid↗

PubMed1985

Cell shape of polymorphonuclear leukocytes is influenced by opioids.

The effects of beta-endorphin(beta-End), an endogenous opioid, were tested in vitro on shape changes in polymorphonuclear leukocytes (PMNs). Cell shape changes indicate alterations of the functional status of the cells. Within 2 min, beta-End but not the opioid alkaloid levorphanol or the antagonist, diprenorphine, induced a cell spreading. Subsequently, beta-End and levorphanol (10(-8) M), but not the dextrorotatory isomer, stimulated an elongation of the cells. Both effects of beta-End could be antagonized by diprenorphine in an equimolar concentration. Thus, the effects were stereo-specific and antagonizable. In this test system, the morphological changes evoked by beta-End were equal to the effects of FMLP, a chemotactic substance, used as a reference. Our findings indicate that endogenous opioids might play a role in modulating the initial phase of the PMNs' offensive behaviour, presumably cell adherence and motility.

Cell Adhesion↗

PubMed1984

Beta-endorphin modulates immune functions. A review.

The investigation of psychoneuroimmunological pathways represents a growing field of research. This paper reviews the current state of knowledge about a direct correlation of endogenous opioids and immunologically competent cells.

Basophils↗