Stimulation of phagocytic function in mouse macrophages by neurotensin and neuromedin N.
The neuropeptides neurotensin and neuromedin N (from 10(-12) M to 10(-9) M) have been shown in this study to stimulate significantly in vitro several steps of the phagocytic process: adherence to substrate, chemotaxis, ingestion of inert particles (latex beads) and production of superoxide anion measured by nitroblue tetrazolium reduction in resting peritoneal macrophages from BALB/c mice. A dose-response relationship was observed, with a maximal stimulation of the phagocytic process at 10(-11) M. The two neuropeptides induced no change of intracellular cyclic AMP in murine macrophages. Moreover, adherence and chemotaxis decreased significantly in the presence of EGTA (1 mM), a chelator of extracellular Ca2+, or ryanodine (0.5 mM), a blocker of a Ca(2+)-gated channel from the endoplasmic reticulum, in both controls and samples with the addition of neurotensin or neuromedin N. These results suggest that there is no relation between the cAMP messenger system and the phagocytic process stimulation in murine peritoneal macrophages by neurotensin or neuromedin N. In addition, the results observed with EGTA and ryanodine could indicate that these two neuropeptides produce their effects through an increase of intracellular Ca2+ concentration.
Departamento de Fisiología Animal, Facultad de C. Biológicas, Universidad Complutense, Madrid, Spain.
M
M
De la Fuente
J J
JJ
Garrido
R M
RM
Arahuetes
A
A
Hernanz
D000818:Animals; D002448:Cell Adhesion / Q000187:drug effects; D002633:Chemotaxis / Q000187:drug effects; D000242:Cyclic AMP / Q000032:analysis; D004533:Egtazic Acid / Q000494:pharmacology; D008264:Macrophages / Q000737:chemistry / Q000276:immunology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009496:Neurotensin / Q000494:pharmacology*; D009580:Nitroblue Tetrazolium; D010446:Peptide Fragments / Q000494:pharmacology*; D010529:Peritoneal Cavity / Q000166:cytology; D010587:Phagocytosis / Q000187:drug effects / Q000502:physiology*; D012433:Ryanodine / Q000494:pharmacology
D010446:Peptide Fragments; C042090:neuromedin N; D012433:Ryanodine; D009580:Nitroblue Tetrazolium; D009496:Neurotensin; D004533:Egtazic Acid; D000242:Cyclic AMP