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  • 1985-1989  (2)
  • 1965-1969
  • Chemotaxis  (1)
  • Serum-free medium  (1)
  • 1
    ISSN: 1432-1912
    Keywords: Tachykinins ; Calcitonin gene related peptide ; Neutrophils ; Monocytes ; Chemotaxis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Polymorphonuclear leukocytes (PMNL) are a component of the inflammatory response to neurogenic mediators. Using the micropore filter approach, the authors studied the chemoattracting properties of tachykinins, including substance P (SP), neurokinin A (NKA) and neurokinin B (NKB), and that of calcitonin gene-related peptide (CGRP) for human PMNL in vitro and now show that SP in near nanomolar concentrations stimulates locomotion of human PMNL. Locomotion of PMNL is induced by SP, aminoterminal SP (1–9) and the SP receptor antagonist [d-pro2, d-trp7,9]-SP (DPDT) but not by carboxyterminal SP (3–11), NKA, NKB, or CGRP suggesting that the aminoterminal amino acids arginine and proline, are essential residues of SP in activation of PMNL locomotion. In contrast, the migratory effect of SP on monocytes resides in the carboxyterminal SP amino acid sequence, which is in agreement with carboxyterminal, SP receptor-mediated chemotaxis of human monocytes previously shown by others. From the known structure-activity relationships for SP receptors it is concluded that induction of PMNL migration by SP does not involve neurokinin-1 (NK-1), NK-2 or NK-3 receptors. “Checkerboard” analysis reveals that PMNL locomotion by SP is not dependent on concentration gradients and thus represents chemokinesis, which is enhancement of speed and/or frequency of locomotion. One cannot exclude that this action of SP on PMNL is mediated by the aminoterminal sequence via yet unknown SP “receptors”. Since structure-activity relationships appear to be similar to the mast cell degranulating actions of tachykinins, which also critically depend on the aminoterminal sequence, it may correspondingly be regarded as non-receptorial mechanism, due to membrane interaction of the basic groups in the N-terminal region of the peptide.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-0584
    Keywords: Human bone marrow cells ; Erythropoiesis ; Serum-free medium ; CFU-e ; BFU-e
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The purpose of the present study was to investigate the influence of human lipoproteins on CFU-e and BFU-e proliferation from human bone marrow in a serum-free system. In our previously described miniaturized agar system the main lipoprotein-density-classes from human plasma, namely very low density lipoproteins (VLDL), intermediate density lipoproteins (IDL), low density lipoproteins (LDL), high density lipoproteins2 (HDL2) and HDL3 and a mixture of all the five lipoproteins were added in rising concentrations (from 1/10 to normal human plasma concentration) to serum-free medium containing delipidated and deionized bovine serum albumin (BSA), iron saturated transferrin and erythropoietin. The results demonstrate that all lipoproteins markedly increased the CFU-e and BFU-e proliferation after 7 and 14 days of incubation, respectively. Moreover, the lipoproteins induced a shift towards a lower threshold concentration of erythropoietin. Serumlike conditions were obtained if LDL and the mixture of lipoproteins were added to serum-free medium. Furthermore, in the serum-free cultures a maturation to the mature erythrocyte could be found.
    Type of Medium: Electronic Resource
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