Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P20366 (substance P)
 21,176 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To find new tachykinin NK1 receptor antagonists from natural sources, we examined the tachykinin antagonist activity in the extracts of approximately 200 species of plants by the use of isolated guinea pig ileum. As a result, we discovered a novel and potent NK1 receptor antagonist in the extract of dried flowers of Matricaria chamomilla L. (chamomile). The structure of the antagonist was established as N1,N5,N10,N14-tetrakis[3-(4-hydroxyphenyl)-2-propenoyl]-1,5,10,14-tetraazatetradecane (tetracoumaroyl spermine, 1a). The Ki values of 1a, estimated from the inhibitory action on the substance P (SP)-induced contraction of the guinea pig ileum and the inhibition of the binding of [3H][Sar9, Met(O2)11]SP to human NK1 receptors, were 21.9 nM and 3.3 nM, respectively. 1a is the first potent NK1 receptor antagonist from natural sources and it has a unique structure of a polyacylated spermine. 1a was concentrated in pollen of Matricaria chamomilla L. and was also found in the extracts of flowers of other four species of Compositae. In addition, we found N1,N5,N10-tris[3-(4-hydroxyphenyl)-2-propenoyl]-1,5,10,14-tetraazatetradecane (2) as a new compound in the extract of flowers of Matricaria chamomilla L., which did not exhibit any tachykinin antagonist activity. A number of related compounds were synthesized, and the structure-activity relationship was studied.
 ...
PMID:A new nonpeptide tachykinin NK1 receptor antagonist isolated from the plants of Compositae. 1182 84

This study characterizes the molecular neurotoxicity of diesel exhaust (DE) on the tachykinin substance P (SP) signaling system in the lungs. A total of 96 female Fischer 344/NH rats (approximately 175 g, approximately 4 weeks old) were randomly assigned to eight groups in a 2 x4 factorial design: capsaicin versus non-capsaicin (vehicle) pretreatment, and filtered room air versus two exposure levels of DE with diesel engine room control. The rats were exposed nose-only to room air or low (35.3 micro g/m(3)) and high concentrations (669.3 micro g/m(3)) particulates directly from a Cummins N14 research engine at 75% throttle for 4 h/day, 5 days/week, for 3 weeks. The findings showed that exposure to DE dose-dependently induced bronchopulmonary neurogenic inflammation, both in capsaicin- and vehicle-pretreated rats, as measured by plasma extravasation, edema, and inflammatory cells. DE inhalation affected the SP signaling processes, including stored SP depletion and the gene/protein overexpression for neurokinin-1 receptor. DE also significantly reduced the activity of neutral endopeptidase, a main degradation enzyme for SP. Consequently, these changes may be regarded as critical factors that switched neurogenic pulmonary responses from their protective functions to a detrimental role that perpetuates lung inflammation. These changes may possibly be associated with the mass concentration of DE particles due to their physico-chemical characteristics. Moreover, capsaicin-pretreated rats had more sensitivity to these levels of DE exposure due to stimulation of bronchopulmonary C-fibers. However, the effects of capsaicin treatment were not consistent and apparent in this study. Taken together, our findings suggest that neurokininergic mechanisms may possibly be involved in DE-induced lung inflammation, but that bronchopulmonary C-fibers did not dominate DE-induced inflammatory abnormalities.
 ...
PMID:Tachykinin substance P signaling involved in diesel exhaust-induced bronchopulmonary neurogenic inflammation in rats. 1368 92

Using an in-line, real-time, in vivo exposure system, we investigated whether acute adverse effects of diesel exhaust (DE*) exposure involve neurogenic inflammation in the lungs via sensory nerve C fibers. A total of 168 female F344 rats (175 g, 8 weeks old) were randomly assigned to pretreatment with capsaicin or saline to deplete C-fiber neurotransmitters. In a 2 x 3 factorial design, groups of animals were then exposed nose-only to a low level of DE (LDE, 35.3 microg/m3), a high level of DE (HDE, 632.9 microg/m3), or side-stream cigarette smoke (CS, 0.4 mg/m3). Two control groups were exposed whole body to filtered air in the animal room (fRA) or unfiltered air in the diesel engine room (eRA), respectively. DE was taken directly from a heavy-duty Cummins N14 research engine operated at 75% throttle (California Air Resources Board [CARB] 8, mode 6). Exposure to DE or air was 4 hours/day, 5 days/week, for 3 weeks. Exposure to CS was for 4 hours/day for 7 days. Involvement of neurogenic inflammation in the response to DE or CS was assessed via comparison of plasma extravasation, a sensitive endpoint of neurogenic inflammation, between rats with and without capsaicin pretreatment. Lung injury was assessed via analysis of proinflammatory cytokines, respiratory permeability, and histopathology. Moreover, whether DE exposure affected the molecular mechanisms of neurogenic inflammation was analyzed through quantification of substance P (SP) and its primary neurokinin-1 (NK1) receptor at the gene and protein levels and through neutral endopeptidase (NEP) activity. DE and CS exposure induced dose-dependent plasma extravasation, which may play an important role in initiating the associated lung inflammation and injury. Exposure of rats to DE affected the SP signaling pathway as indicated by overexpression of the NK1 receptor or reduction of SP in the lung tissue. DE exposure consistently inactivated tissue NEP, a key factor that switches neurogenic inflammation from its physiological and protective functions to a role that increases and perpetuates lung injury. The roles of these overlapping neurokininergic mechanisms in the initiation of DE-associated lung injury are plausible, and these changes may contribute to DE-associated respiratory disorders. Capsaicin rats followed the same trends as those of saline animals when exposed to DE or CS: capsaicin rats did not have significantly different plasma extravasation in the airways or lung parenchyma compared to their corresponding controls. Histopathology evaluation likewise demonstrated the same degree of tissue changes, such as edema and alveolar macrophage collection, in capsaicin and saline rats after the same level of DE exposure. In summary, our data suggest that neurokininergic mechanisms may have been involved in DE-induced inflammatory conditions in rat lung but that C fibers did not appear to be involved under these exposure conditions. We believe that time-course or protein knockdown/knockout animal studies are required to characterize further the role of neurokininergic mechanisms in DE-induced lung injury.
 ...
PMID:Neurogenic responses in rat lungs after nose-only exposure to diesel exhaust. 1591 11