Substance P enhances electrical field stimulation-induced mast cell degranulation in rat trachea

1996 ◽  
Vol 270 (6) ◽  
pp. L985-L991 ◽  
Author(s):  
X. Y. Hua ◽  
S. M. Back ◽  
E. K. Tam

We previously demonstrated in an ex vivo rat tracheal model that chymotryptic activity is an index of mast cell degranulation and that substance P (SP) and electrical field stimulation (EFS) synergistically degranulate mucosal and connective tissue mast cells. In the current study, we found that the facilitatory effect of SP was apparent at concentrations as low as 10(-9) M. This effect was mimicked by 10(-7) M neurokinin A or by 10(-6) M capsaicin and was blocked by the NK1 receptor antagonist CP-96,345. SP + EFS-induced mast cell secretion was significantly attenuated by 10(-6) M tetrodotoxin. The response was also attenuated in tracheas from rats in which sensory nerves had been depleted by systemic pretreatment with capsaicin or in which sympathetic nerves had been depleted by systemic pretreatment with 6-hydroxy-dopamine. Atropine (10(-6) M) or indomethacin (10(-5) M) also attenuated SP + EFS-induced mast cell secretion. Our findings suggest the importance of a sensitizing rather than a direct stimulating effect of SP on mast cell degranulation. SP may increase the sensitivity of mast cells to EFS-discharged mediators or facilitate the release of mast cell-stimulating mediators from autonomic nerves.

2004 ◽  
Vol 287 (1) ◽  
pp. L168-L175 ◽  
Author(s):  
Z.-X. Wu ◽  
Q. H. Yang ◽  
T. Ruan ◽  
L.-Y. Lee

We investigated whether the airway constrictive response to stimulation of bronchopulmonary C-fiber afferents is altered during the maturation process. Isometric tension was measured in airway rings isolated from three tracheobronchial locations (intrathoracic trachea and main and hilar bronchi) and compared in mature [M, 407 ± 10 (SE) g body wt, n = 36] and immature (IM, 161 ± 5 g body wt, n = 35) guinea pigs. Our results showed no difference in the ACh (10−5 M)- or KCl (40 mM)-induced contraction between M and IM groups, regardless of the airway location. In sharp contrast, the concentration-response curves of 10−8–10−6 M capsaicin were distinctly lower in IM hilar bronchi; for example, response to the same concentration of capsaicin (10−6 M) was 89.2 ± 15.3% of the response to 10−5 M ACh in IM and 284.7 ± 43.2% in M animals. Similar, but smaller, differences in the bronchoconstrictive response to capsaicin between IM and M groups were also observed in the trachea and main bronchus. Electrical field stimulation induced airway constriction in all three locations in M and IM groups. However, after administration of 10−6 M atropine and 10−6 M propranolol, electrical field stimulation-induced contraction was significantly smaller in the hilar bronchus of IM than M animals, and this difference was not prevented by pretreatment with 5 × 10−5 M indomethacin. Although radioimmunoassay showed no difference in the tissue content of substance P between M and IM airways, the constrictive responses to exogenous substance P and neurokinin A were markedly greater in M airways at all three locations. In conclusion, the constriction of isolated airways evoked by C-fiber stimulation was significantly weaker in the IM guinea pigs, probably because of a less potent effect of tachykinins on the airway smooth muscle.


2018 ◽  
Vol 115 (40) ◽  
pp. E9381-E9390 ◽  
Author(s):  
Alexandra Taracanova ◽  
Irene Tsilioni ◽  
Pio Conti ◽  
Errol R. Norwitz ◽  
Susan E. Leeman ◽  
...  

Mast cells are critical for allergic and inflammatory responses in which the peptide substance P (SP) and the cytokine IL-33 are involved. SP (0.01–1 μM) administered together with IL-33 (30 ng/mL) to human cultured LAD2 mast cells stimulates a marked increase (P< 0.0001) in secretion of the proinflammatory cytokine IL-1β. Preincubation of LAD2 (30 min) with the SP receptor (NK-1) antagonists L-733,060 (10 μM) or CP-96345 (10 µM) inhibits (P< 0.001) secretion of IL-1β stimulated by either SP (1 μM) or SP together with IL-33 (30 ng/mL). Surprisingly, secretion of IL-1β stimulated by IL-33 is inhibited (P< 0.001) by each NK-1 antagonist. Preincubation with an antibody against the IL-33 receptor ST2 inhibits (P< 0.0001) secretion of IL-1β stimulated either by IL-33 or together with SP. The combination of SP (1 μM) with IL-33 (30 ng/mL) increases IL-1β gene expression by 90-fold in LAD2 cells and by 200-fold in primary cultured mast cells from human umbilical cord blood. The combination of SP and IL-33 increases intracellular levels of IL-1β in LAD2 by 100-fold and gene expression of IL-1β and procaspase-1 by fivefold and pro-IL-1β by twofold. Active caspase-1 is present even in unstimulated cells and is detected extracellularly. Preincubation of LAD2 cells with the natural flavonoid methoxyluteolin (1–100 mM) inhibits (P< 0.0001) secretion and gene expression of IL-1β, procaspase-1, and pro-IL-1β. Mast cell secretion of IL-1β in response to SP and IL-33 reveals targets for the development of antiinflammatory therapies.


1997 ◽  
Vol 273 (2) ◽  
pp. G456-G463 ◽  
Author(s):  
M. C. Baccari ◽  
C. Iacoviello ◽  
F. Calamai

The effects of the nitric oxide (NO) synthesis inhibitors, NG-nitro-L-arginine (L-NNA) and NG-nitro-L-arginine methyl ester (L-NAME), on the electrical field stimulation (EFS)-induced inhibitory responses were investigated. EFS caused, in strips contracted by means of substance P (SP), prostaglandin F2 alpha (PGF2 alpha), or carbachol (CCh), a fast relaxant response that, depending on stimulation frequency and strip tension, could be followed by a slower, sustained relaxation. The NO synthesis inhibitors blocked the EFS-induced fast relaxations and often reversed them into contractions; these effects were greatly counteracted in SP- or PGF2 alpha-treated strips by scopolamine or atropine. In CCh-precontracted strips, either L-NNA or L-NAME became progressively unable to block the EFS-induced fast relaxations as the CCh concentration was increased. The NO synthesis inhibitors greatly reduced the sustained relaxant responses elicited either by EFS or exogenous vasoactive intestinal polypeptide (VIP). The results indicate that the NO synthesis inhibitors abolish the neurally induced fast relaxation by interfering with the cholinergic excitatory pathway. The involvement of both VIP and NO in sustained relaxations is also suggested.


1998 ◽  
Vol 112 (5) ◽  
pp. 577-591 ◽  
Author(s):  
Dorothea Lorenz ◽  
Burkhard Wiesner ◽  
Josef Zipper ◽  
Anett Winkler ◽  
Eberhard Krause ◽  
...  

Substance P and other polycationic peptides are thought to stimulate mast cell degranulation via direct activation of G proteins. We investigated the ability of extracellularly applied substance P to translocate into mast cells and the ability of intracellularly applied substance P to stimulate degranulation. In addition, we studied by reverse transcription–-PCR whether substance P-specific receptors are present in the mast cell membrane. To study translocation, a biologically active and enzymatically stable fluorescent analogue of substance P was synthesized. A rapid, substance P receptor- and energy-independent uptake of this peptide into pertussis toxin-treated and -untreated mast cells was demonstrated using confocal laser scanning microscopy. The peptide was shown to localize preferentially on or inside the mast cell granules using electron microscopic autoradiography with 125I-labeled all-D substance P and 3H-labeled substance P. Cell membrane capacitance measurements using the patch-clamp technique demonstrated that intracellularly applied substance P induced calcium transients and activated mast cell exocytosis with a time delay that depended on peptide concentration (delay of 100–500 s at concentrations of substance P from 50 to 5 μM). Degranulation in response to intracellularly applied substance P was inhibited by GDPβS and pertussis toxin, suggesting that substance P acts via G protein activation. These results support the recently proposed model of a receptor-independent mechanism of peptide-induced mast cell degranulation, which assumes a direct interaction of peptides with G protein α subunits subsequent to their translocation across the plasma membrane.


1997 ◽  
Vol 273 (1) ◽  
pp. L40-L45 ◽  
Author(s):  
F. H. Agani ◽  
N. T. Kuo ◽  
C. H. Chang ◽  
I. A. Dreshaj ◽  
C. F. Farver ◽  
...  

This study was undertaken to characterize changes in the tachykinin system induced by hyperoxic exposure and the potential effects on airway contractile responses. We exposed 7-day-old rat pups to either room air or hyperoxia (> 95% O2) for 7 days to assess pulmonary beta-preprotachykinin (beta-PPT) gene expression, substance P (SP) levels, and airway contractile responses to cholinergic stimulation before and after neurokinin-1 (NK1) receptor blockade. Lung beta-PPT mRNA expression, lung and tracheal SP levels, and contractile responses to exogenous acetylcholine and electrical field stimulation were measured in vitro in normoxia- and hyperoxia-exposed tracheal cylinders. Hyperoxia caused a 1.1- to 2.6-fold increase in steady-state lung beta-PPT mRNA and a 50 and 32% increase in SP levels of lung and trachea, respectively. In response to cholinergic stimulation, maximal contractile force (Emax) of hyperoxia exposed tracheal muscle was significantly higher than for normoxic controls. Addition of the SP (NK1) receptor blocker CP-99994 (10 microM) decreased sensitivity to electrical field stimulation in both hyperoxic and normoxic trachea without a significant decline in Emax. These data provide evidence for both increased SP production and enhanced maximal contractile responses of hyperoxia-exposed neonatal trachea to cholinergic stimulation. The tachykinin peptide SP does not, however, appear to play a major role in the enhanced airway reactivity associated with hyperoxic lung injury during early postnatal life.


1981 ◽  
Vol 153 (3) ◽  
pp. 520-533 ◽  
Author(s):  
W R Henderson ◽  
E Y Chi ◽  
E C Jong ◽  
S J Klebanoff

Mast cells, when supplemented with H2O2 and iodide, are cytotoxic to mammalian tumor cells as determined by 51Cr release, and transmission and scanning electron microscopy. H2O2 at the concentration employed (10(-4) M) initiates mast cell degranulation, and mast cell granules (MCG), which contain a small amount of endogenous peroxidase activity, are toxic to tumor cells when combined with H2O2 and iodide. This toxicity is greatly increased by binding eosinophil peroxidase (EPO) to the MCG surface. Each component of the mast cell, MCG, or MCG-EPO system was required and toxicity was inhibited by the addition of the hemeprotein inhibitors azide or aminotriazole, which is compatible with a requirement for peroxidase in the cytotoxic reaction. A sequence of reactions is proposed in which mast cells, stimulated to release their granules by H2O2 generated by adjacent phagocytes, react with H2O2 and a halide to damage tumor cells. EPO release from eosinophils may contribute to this sequence of reactions, both by stimulation of H2O2-induced mast cell secretion and by combination with MCG to form a complex with augmented tumoricidal activity. These rections may play a role in the host defense against neoplasms.


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