SP-positive Nerve Fibers Research Articles

Distribution of Nerve Fibers in Abdominal Wall Endometriosis and Their Clinical Significance.

This study aimed to explore the distribution of nerve fibers in abdominal wall endometriosis (AWE) and discern their association with pain. A retrospective case-control study was conducted. The cases comprised 30 patients diagnosed with AWE, while the control group consisted of 17 patients who had undergone laparotomy without any history of endometriosis. We analyzed clinical characteristics and examined the innervation patterns in samples using stains for S-100, neuron-specific enolase (NSE), protein gene product 9.5 (PGP9.5), neurofilament (NF), and substance P (SP) antibodies. There was a notable increase in the density of S-100, NSE and PGP9.5 immunoreactive nerve fibers and a higher proportion of SP positivity in AWE lesions compared to standard abdominal wall scars (p < 0.05). However, there were no significant differences in the density or proportion of NF-immunoreactive nerve fibers between the cases and the controls. Moreover, no statistically significant correlation was observed between the density of S-100, NSE, PGP9.5, NF, or SP-positive nerve fibers and pain scores. This study demonstrated an increased immunoreactive nerve fiber density located in AWE lesions compared to normal abdominal wall scars. Further high-quality studies are needed to investigate the mechanisms responsible for pain in women with endometriosis.

OR20-4 Expression of the Neuropeptide Substance P and the NK1 Receptor in Aldosterone-Producing Adenomas

Abstract Background Aldosterone-producing adenoma (APA) is a major cause of primary aldosteronism (PA) which is the most frequent form of secondary hypertension (1-2). The pathophysiology of PA is quite complex and still incompletely understood. Substance P (SP) encoded by the TAC1 gene belongs to a family of bioactive peptides named tachykinins. A recently published study indicated that SP, released by subcapsular nerve fibres, stimulates aldosterone production through activation of the neurokinin type 1 receptor (NK1R) in the human adrenal gland (3). The aim of our work was to investigate the presence of SP fibres and the NK1 receptor in a large series of APA in order to assess the potential role of this peptide in the pathophysiology of PA. Methods APA tissues were studied by molecular and histological approaches. Expression of SP and NK1 receptor was searched for in a series of 51 APA by RT-Q-PCR and immunohistochemistry. Results Quantitative RT-PCR data indicated that adenomas strongly express TAC1 mRNA. Immunohistochemistry showed the presence of SP-positive nerve fibres in APAs tissues. SP was also detected in a subpopulation of adenomatous cells. Adenomas strongly express mRNA encoding the NK1 receptor. The distribution of the NK1 receptor within APAs is similar to that of aldosterone synthase (CYP11B2), suggesting that SP may regulate aldosterone secretion by APAs. Conclusion These results suggest that SP and its NK1 receptor may be involved in the pathophysiology of aldosterone hypersecretion by APAs.

Chronic Exposure to Cigarette Smoke Affects the Ileum and Colon of Guinea Pigs Differently. Relaxin (RLX-2, Serelaxin) Prevents Most Local Damage

Cigarette smoking (CS) is the cause of several organ and apparatus diseases. The effects of smoke in the gut are partially known. Accumulating evidence has shown a relationship between smoking and inflammatory bowel disease, prompting us to investigate the mechanisms of action of smoking in animal models. Despite the role played by neuropeptides in gut inflammation, there are no reports on their role in animal models of smoking exposure. The hormone relaxin has shown anti-inflammatory properties in the intestine, and it might represent a putative therapy to prevent gut damage caused by smoking. Presently, we investigate the effects of chronic smoke exposure on inflammation, mucosal secretion, and vasoactive intestinal peptide (VIP) and substance P (SP) expressions in the ileum and colon of guinea pigs. We also verify the ability of relaxin to counter the smoke-induced effects. Smoke impacted plasma carbon monoxide (CO). In the ileum, it induced inflammatory infiltrates, fibrosis, and acidic mucin production; reduced the blood vessel area; decreased c-kit-positive mast cells and VIP-positive neurons; and increased the SP-positive nerve fibers. In the colon, it reduced the blood vessel area and the goblet cell area and decreased c-kit-positive mast cells, VIP-positive neurons, and SP-positive nerve fibers. Relaxin prevented most of the smoking-induced changes in the ileum, while it was less effective in the colon. This study shows the diverse sensitivity to CS between the ileum and the colon and demonstrates that both VIP and SP are affected by smoking. The efficacy of relaxin proposes this hormone as a potential anti-inflammatory therapeutic to counteract gut damage in humans affected by inflammatory bowel diseases.

Активность нейрокининовой системы в слизистой оболочке полости носа при полипозном риносинусите

A study of changes in the activity of elements of the neurokinin system in the tissues of the mucous membrane of the nose in patients with rhinosinusitis with nasal polyps was carried out. The object of the study was human material, polyps of the nasal cavity, and areas of the mucous membrane of the inferior turbinates. The material was obtained from female and male patients aged 30 to 75 years, a total of 70 people (50 patients in the study group and 20 patients in the control group). To solve this problem, we used immunohistochemistry to study the localization and distribution of SP (Substance undecaPeptide) and NK1 (neurokinin1)-positive elements in polyps and mucous membranes of the nose. It was found that the formation of polyposis changes in the nasal cavity is accompanied by morpho-chemical changes in the areas of the mucosa of the inferior turbinates. Analyzing the activity of SP in the nasal mucosa in control patients and patients with polyps of different types, an increase in the number of SP-positive nerve fibers and positive cellular elements of inflammatory infiltrates in the tissues of mucous membrane with an allergic type of polyp is noted. The features of the specific signaling microenvironment in the nasal cavity, providing special conditions for the formation of various types of polyposis changes, have been revealed. The specificity of the activity and distribution of markers of the inflammatory process in the tissues of polyps of different morphological types may serve as a prerequisite for the development of methods for treating this pathology.

Anti-inflammatory role of methotrexate in adjuvant arthritis: effect on substance p and calcitonin gene-related Peptide in thymus and spleen.

To investigate the anti-inflammatory effect of methotrexate (MTX) in rats with adjuvant arthritis through its influence on the expression of proinflammatory neuropeptides, substance P (SP) and calcitonin gene-related peptide (CGRP) in immune organs, thymus and spleen. Phase-I pre-clinical trial. The Aga Khan University, Karachi, from July to December 2003. Adjuvant arthritis was induced in rats by inoculation with heat-killed mycobacteria. One group of arthritic rats (n=6) was treated with MTX (0.2 mg/kg body weight, subcutaneously) on every 4th day for a period of 18 weeks, while another group of arthritic rats (n=6) was treated with physiological saline served as control. At the end of experiment, animals were sacrificed and thymus and spleen were dissected and prepared for immunohistochemical analysis. The neuronal density of SP and CGRP immunoreactivity in thymus and spleen was assessed by semi-quantitative analysis. There was a marked reduction in hind paw swelling and inflammation in the MTX-treated rats after 18 weeks of treatment. Restoration of joint spaces (tibiotalar and subtalar) was seen after 9 weeks of MTX treatment. CGRP-positive nerve fibres were significantly reduced (p=0.0001) in thymus of rats treated with MTX compared to control rats. SP-positive nerve fibers were also found to be decreased in thymus of rats treated with MTX compared to controls, however, the decrease was not statistically significant. The neuronal density of SP and CGRP-immunoreactivity in spleen was not significantly different in MTX-treated and placebo-treated rats. In arthritic rats, MTX significantly reduced CGRP expression in thymus. Suppression of pro-inflammatory neuropeptides, such as CGRP and probably SP could be another mechanism by which MTX produces its anti-inflammatory effect in adjuvant arthritis.

Changes in peptidergic fiber density in the synovium of mice with collagenase-induced acute arthritis.

The effect of acute osteoarthritis (OA) on peripheral nerve fibers (NFs) in synovial tissue, and their association with histological changes were investigated in collagenase-induced OA mice. Collagenase (10 U in 5 μL saline) was injected into the right knee, and the same volume of saline was injected into the left knee as the control. Mice were sacrificed 1, 2, 3, and 4 weeks after the collagenase injection. Histopathological changes in the knee joints were evaluated. The numbers of protein gene product (PGP) 9.5-, calcitonin-gene-related peptide (CGRP)-, and substance P (SP)-positive NFs in the synovial tissue were determined, and their densities in the tissue were calculated. The densities of PGP 9.5- and CGRP-positive NFs in the synovium were drastically decreased 1 week after the collagenase injection. However, by week 4, the density of PGP 9.5- and CGRP-positive NFs had recovered to 84% and 79% of their normal levels, respectively. Despite the poor correlation between the synovitis score and the density of CGRP- or SP-positive NFs in the synovium, the ossification rate of chondrophytes in chondro/osteophyte lesions correlated strongly with the density of CGRP-positive NFs (R = 0.855). These results suggest that the ossification of chondrophytes occurred in parallel with the increase in CGRP-positive fiber density in the synovium during the acute phase of collagenase-induced OA.

PROTEASE-ACTIVATED RECEPTORS ARE EXPRESSED IN HUMAN TENDON TISSUE AND MAY EXPLAIN EXCESSIVE PAIN-SIGNALLING IN TENDINOPATHY

IntroductionSeveral painful conditions throughout the human body—such as interstitial cystitis, Dupuytren's contracture, and complex regional pain syndrome—have been shown to exhibit tissues with an increase in mast cell population. One...

Anatomical study of the human discomallear ligament using cone beam computed tomography imaging and morphological observations

In the present study, the human discomallear ligament (DML) was observed in structures at both macroscopic and cone beam computed tomography levels. Assessments were made regarding the distribution of calcitonin-gene-related peptide (CGRP), protein gene-product (PGP) 9.5, and substance P (SP) of the DML based on immunohistochemical analyses of the anatomical properties of jaw movements using 27 Japanese human cadavers (mean, 79.3 +/- 8.6 years; male, 74.9 +/- 8.0; female, 82.8 +/- 7.5). The DML of the anterior region was connected to the TMJ disc. The DML of the posterior region was attached to both the head and the anterior process of the malleus through the petrotympanic fissure, which formed a narrow channel. The structure of the petrotympanic fissure through the DML was attached to the malleus, and this structure was associated with the mobility of the malleus. In the anterior and posterior parts of the disc-associated connective tissue of the DML, CGRP-, PGP9.5- and SP-positive nerve fibers were located around numerous blood vessels, a condition which may be correlated with chronic pain syndrines disorders and the auditory system.

Somatostatin, substance P and calcitonin gene-related peptide-positive intramural nerve structures of the human large intestine affected by carcinoma.

The aim of this study was to investigate the arrangement and chemical coding of enteric nerve structures in the human large intestine affected by cancer. Tissue samples comprising all layers of the intestinal wall were collected during surgery form both morphologically unchanged and pathologically altered segments of the intestine (n=15), and fixed by immersion in buffered paraformaldehyde solution. The cryostat sections were processed for double-labelling immunofluorescence to study the distribution of the intramural nerve structures (visualized with antibodies against protein gene-product 9.5) and their chemical coding using antibodies against somatostatin (SOM), substance P (SP) and calcitonin gene-related peptide (CGRP). The microscopic observations revealed distinct morphological differences in the enteric nerve system structure between the region adjacent to the cancer invaded area and the intact part of the intestine. In general, infiltration of the cancer tissue resulted in the gradual (depending on the grade of invasion) first decomposition and reduction to final partial or complete destruction and absence of the neuronal elements. A comparative analysis of immunohistochemically labeled sections (from the unchanged and pathologically altered areas) revealed a statistically significant decrease in the number of CGRP-positive neurons and nerve fibres in both submucous and myenteric plexuses in the transitional zone between morphologically unchanged and cancer-invaded areas. In this zone, a decrease was also observed in the density of SP-positive nerve fibres in all intramural plexuses. Conversely, the investigations demonstrated statistically insignificant differences in number of SP- and SOM-positive neurons and a similar density of SOM-positive nerve fibres in the plexuses of the intact and pathologically changed areas. The differentiation between the potential adaptive changes in ENS or destruction of its elements by cancer invasion should be a subject of further investigations.

Effect of epinastine hydrochloride on murine self-scratching behavior after skin-scratching stimulation

The itch-scratch cycle aggravates chronic inflammatory skin diseases. We have previously reported that mice begin to scratch themselves within several minutes after skin-scratching stimulation. This is associated with an increase in release of substance P (SP) from sensory nerve fibers in the skin, and the self-scratching behavior is suppressed by neurokinin-1 receptor (NK-1R) antagonist. Thus, SP may play a pivotal role in self-scratching behavior. The purpose of this study was to investigate the effect of second-generation histamine H(1)-receptor antagonists on self-scratching behavior in mice. After oral administration of epinastine hydrochloride (epinastine) (total dose 50 +/- 5 mg/kg for 7 days) or the vehicle only to ICR mice for 7 days, skin-scratching stimulation was administered to the dorsal skin for 10 min. Self-scratching behavior was recorded by video camera for 10 min. Twenty-four hours later, skin tissue was harvested and stained with toluidine blue. Immunohistochemical staining for SP was performed, and SP and nerve growth factor (NGF) concentrations were measured by enzyme-linked immunosorbent assay. Self-scratching behavior, mast cell degranulation, and NGF concentration decreased, and the length of SP-positive nerve fibers and SP concentrations increased significantly in the epinastine-treated group, when compared with the vehicle control group. We conclude that epinastine inhibits mast cell degranulation by attenuating SP release from sensory nerve fibers, which results in inhibition of self-scratching behavior. These results suggest that second-generation histamine H(1)-receptor antagonists might efficaciously control itch-scratch cycle-related skin diseases.

Multiple sclerosis produces significant changes in urinary bladder innervation which are partially reflected in the lower urinary tract functional status-sensory nerve fibers role in detrusor overactivity

Background Detrusor overactivity is often observed in patients with multiple sclerosis (MS), and neurotoxins are emerging as second-line therapies albeit with different degrees of success per patient basis. Objective To investigate lower urinary tract (LUT) functional status and bladder innervation (calcitonin gene related peptide [CGRP] and substance P [SP] positive nerve fibers) in patients with MS. Method Eighteen MS patients with LUT symptoms underwent urodynamic investigations, and six non-MS patients undergoing cystoscopy due to microscopic hematuria served as controls. Cold cut bladder biopsies were taken from the bladder trigone region. Neurotransmitter expression was determined by individual immunohistochemical staining. Results Two distinct groups could be distinguished: group 1 with pronounced neurogenic detrusor overactivity and mild outflow obstruction; group 2 with some degree of neurogenic detrusor overactivity, detrusor hypocontractility during voiding, and high degree of an outflow obstruction. The presence of SP and CGRP immunoreactive + fiber density was observed in greater numbers in group 1. Conclusion Density of CGRP and SP positive nerve fibers within the urinary bladder of patients with MS may be suggestive of functional status of the lower urinary tract, namely denser innervation is observed in patients with mild outflow obstruction and strong detrusor overactivity. This observation could be useful when planning second-line treatment (neurotoxins) in these patients. Patients with denser innervation probably will respond better to such a therapy.

Neurochemical characteristics of paracervical ganglion in the pig

A study on the presence of the selected biologically active substances in nerve structures of the paracervical ganglion in the pig was performed with the use of immunofluorescence and RT-PCR. Immunohistochemical methods revealed that 23% of paracervical ganglion (PCG) neurons contain both tyrosine hydroxylase (TH) and dopamine &amp;beta;-hydroxylase (D&amp;beta;H) and that the remaining 77% contain choline acetyltransferase (ChAT) and vesicular acetylcholine transporter (VAChT). 73% of TH/D&amp;beta;H neurons contained neuropeptide Y (NPY) and 8% contained somatostatin (Som). All ChAT/VAChT positive neurons contained vasoactive intestinal polypeptide (VIP), 87% of them contained Som, 76% contained NPY and 32% contained neuronal nitric oxide synthase (nNOS). Galanin (Gal) was found only in small cells, which were thought to be SIF cells. No pituitary adenylate cyclase-activating polypeptide (PACAP)- or substance P (SP)-positive neurons were found in PCG. Some areas of PCG contained dense plexuses of ChAT- and VAChT-positive nerve fibres. In the ganglion small number of TH-, nNOS-, NPY-, VIP-, Gal-, PACAP-, Som- and SP-positive nerve fibres was also visible. RT-PCR detected the presence of mRNA for TH, ChAT, nNOS, NPY, VIP, Gal and Som, which were visualised as clearly discernible bands on a gel. In cases of PACAP and SP only weak bands were observed.

Dynamic changes in nerve growth factor and substance P in the murine hair cycle induced by depilation

Increasing evidence suggests that various neurotrophins and neuropeptides play an important role in the progression of hair follicle cycling. Among them, nerve growth factor (NGF) and substance P (SP) have attracted special interest recently. However, the interaction between these factors during hair cycling has not yet been systematically studied. We therefore investigated the mutual relationships between NGF and SP and the mechanism by which the anagen stage of the hair cycle is initiated. Fluctuations in numbers of SP-positive nerve fibers and variations in amounts of SP, NGF, and another neurotrophic factor, glial cell-derived neurotrophic factor, in skin in the C57BL/6 mouse depilation-induced hair cycle model, together with the spatiotemporal expression patterns of each of these factors, were followed simultaneously by enzyme-linked immunosorbent assay and immunohistochemistry. The main finding was that a surge in NGF expression and a rapid increase in NGF content in skin is an initial event within 1 day after depilation, followed by elevation of SP content and numbers of SP-containing fibers 2 days after the increase in NGF. Our findings suggest that a rapid and abundant increase in NGF plays a key role in the induction and progression of anagen hair cycling through keratinocyte growth promotion. NGF may also induce plastic changes such as sprouting and hyperplasia in dermal nerve fibers and enhance their SP production. Elevated levels of SP in skin may additionally contribute to the progression of consecutive anagen hair cycles.

Cotransplant of neural stem cells and NT-3 gene modified Schwann cells promote the recovery of transected spinal cord injury

An animal model of transected spinal cord injury (SCI) was used to test the hypothesis that cografted neural stem cells (NSCs) and NT-3-SCs promote morphologic and functional recoveries of injured spinal cord. To explore whether cotransplant of NSCs and NT-3-SCs could promote the injured spinal cord repair. Zhongshan Medical College, Sun Yat-sen University, PR China. Female Sprague-Dawley (SD) rats weighing on 200-220 g were used to prepare SCI models. The spinal cord was transected between T(9) and T(10), then NSCs, SCs+NSCs, LacZ-SCs+NSCs, or NT-3-SCs+NSCs were grafted into the transected site. (1) Part of NSCs could differentiate to neuron-like cells in the transected site and the percentage of differentiation was NT-3-SCs+NSCs group>SCs+NSCs group>NSCs group. (2) In the grafted groups, there were 5-HT, CGRP, and SP positive nerve fibres within the transected site. Some fluorogold (FG)-labeled cells were found in the spinal cord rostral to the transected site, the red nuclei and the inner pyramidal layer of sensorimotor cortex. (3) The cells grafted could enhance the injured neurons survival in inner pyramidal layer of sensorimotor cortex, red nuclei of midbrain, and Clark's nuclei of spinal cord's L1 segment, could decrease the latency and increase the amplitude of cortical somatosensory evoked potential (CSEP) and cortical motor evoked potential (CMEP), and could promote partly structural and functional recovery of the SCI rats. These results demonstrate that cografted NT-3-SCs and NSCs is a potential therapy for SCI. This research was supported by Chinese National Key Project for Basic Research (G1999054009), Chinese National Natural Science Foundation (30270700) and Social Developmental Foundation of Guangdong Province (2003C33808) to YS Zeng; Natural Science Foundation of Guangdong Province (04300468) and Medical Science Research Grant of Guangdong Province (A2004081) to JS Guo.

Role of substance P in stress-derived degranulation of dermal mast cells in mice

The interaction between nerves and mast cells can effect regulation of the immune system and inflammatory responses. Recent studies have shown that various stressors can induce degranulation of dermal mast cells in animals. This study was conducted to confirm that substance P (SP) was involved in the degranulation of dermal mast cells in stress conditions. Using a communication box system, foot shock stress (FS) and psychological stress (PS) were administered to mice and the degranulation rate of dermal mast cells, the number of SP-positive nerve fibers and changes in SP content were determined. The inhibitory effect of a non-peptide NK1-receptor antagonist on these changes was investigated. Both FS and PS significantly enhanced the degranulation of dermal mast cells and increased the number of SP-positive nerve fibers. FS significantly decreased dermal SP content whereas SP was increased by PS. These changes were inhibited by intraperitoneal injection of NK(1) receptor antagonist. It was considered that SP released from the nerve ending, had an important role in the degranulation of dermal mast cells. Results of this study suggest that the tachykinin receptor antagonist exhibited an inhibitory effect on aggravated stress-induced dermatitis.

Distribution of substance-P nerve fibers in intact and ruptured human anterior cruciate ligament: a semi-quantitative immunohistochemical assessment.

Numerous studies have reported qualitative and quantitative analysis of nerve supply in the anterior cruciate ligament; however, as yet relatively little is known about the distribution of substance-P nerve endings in the human anterior cruciate ligament. The objective of this work was to evaluate the distribution of substance-P nerve fibers in intact human anterior cruciate ligament, and determine if rupture of the ligament has any influence on occurrence of these receptors. The intact anterior cruciate ligament group (group 1) of osteoarthritis knee, undergoing total knee arthroplasty, consisted of nine patients (eight females) with a mean age of 65.3 years at surgery. The anterior cruciate ligament rupture group (group 2) consisted of 20 patients (18 males and 2 females) with a mean age of 27.8 years at reconstruction. Healing time of the torn ligament in vivo, determined by the time period between the rupture and reconstruction, lasted from 1 to 40 months and the patients were divided into 3 groups (I, II and III) embracing diverse time periods. All harvested anterior cruciate ligaments were sectioned in thirds so that there was a proximal, middle and distal third for each ligament. The distribution of nociceptive receptors was studied by immunohistochemistry with monoclonal antibody to substance-P, including the semi-quantitative assessment. No significant difference was found between the number of substance-P nerve fibers in the proximal, middle and distal third of the intact anterior cruciate ligament (p>0.05). During the first 4 months after injury (group I) the mean number of neuropeptide-containing fibers was greater in the proximal than in the distal third (p=0.048996). The number of SP-positive nerve fibers in the proximal third decreased between 5 and 12 months after rupture, in a statistically significant manner (p=0.045864). This study showed that distribution of the nociceptive nerve supply, positively stained for substance-P, is equal among the intact anterior cruciate ligament. The substance-P nerve ending density was significantly affected by the injury as well as by the time since rupture. The results of this study provide immunohistochemical evidence suggesting that between 1 to 4 months after rupture the site of the injury undergoes neurogenic inflammation, which could have an influence on the healing course of the torn ligament.

Expression and dynamics of peptidergic nerve fibers in granulation tissue after distance osteosynthesis

The transmitters and/or modulators calcitonin gene-related peptide (CGRP), substance P (SP), neuropeptide Y (NPY) and vasointestinal polypeptide (VIP) are supposed to be involved in bone growth, fracture healing and internal remodeling. Immunohistochemical proof of neuropeptide positive fibers in normal bone let us assume that these substances effect the early phase of fracture healing. Exact time of appearance of neuropeptide positive fibers, localisation in the bone, chemospecifity and mode of genesis are unknown so fare. Research was done on a model of distance osteosynthesis of the rabbit tibia. Primary and secondary antibodies were used for indirect immunohistochemical technique. We put more strength on the concrete stereological calculation of length of the nerve fibers than on a conventional statistical evaluation. After histological preparation of tissue specimens from the interfragmental gap and the bone marrow beside the gap the neuropeptides CGRP, SP and NPY were immunohistochemically expressed. Sprouting of CGRP- and SP-positive nerve fibers has its origin in the bone marrow. A vascularisation in the early state of osteoneogenesis after fracture seems impossible without the nerval peptidergic influence and transmission.

Role of intrinsic airway neurons in ozone-induced airway hyperresponsiveness in ferret trachea.

Exposure to ozone (O(3)) enhances airway responsiveness, which is mediated partly by the release of substance P (SP) from airway neurons. In this study, the role of intrinsic airway neurons in O(3)-induced airway responses was examined. Ferrets were exposed to 2 ppm O(3) or air for 1 h. Reactivity of isolated tracheal smooth muscle to cholinergic agonists was significantly increased after O(3) exposure, as were contractions to electrical field stimulation at 10 Hz. Pretreatment with CP-99994, a neurokinin type 1 receptor antagonist, partially abolished the O(3)-induced reactivity to cholinergic agonists and electrical field stimulation. The O(3)-enhanced airway responses were present in tracheal segments cultured for 24 h, a procedure shown to deplete sensory nerves while maintaining viability of intrinsic airway neurons, and all the enhanced smooth muscle responses were also diminished by CP-99994. Immunocytochemistry showed that the percentage of SP-containing neurons in longitudinal trunk and the percentage of neurons innervated by SP-positive nerve fibers in superficial muscular plexus were significantly increased at 1 h after exposure to O(3). These results suggest that enhanced SP levels in airway ganglia contribute to O(3)-induced airway hyperresponsiveness.

Vasoactive-intestinal-peptide- and substance-P-immunoreactive nerve fibres in the myenteric plexus of mouse colon during the chronic phase of Trypanosoma cruzi infection.

The distribution of a tachykinin (substance P) and vasoactive intestinal peptide (VIP) and the number and morphology of the large granular vesicles (LGV) in the myenteric plexus of the colons of mice were investigated. Six of the 12 young, male, Swiss mice studied had been inoculated with the Y strain of Trypanosoma cruzi 2 months previously whereas the others were uninfected controls. Substance P (SP) and VIP were localized by light microscopy, using an immunohistochemical method, and LGV were counted in sections studied by electron microscopy. There were far fewer LGV and less intensely staining varicose VIP- and SP-positive nerve fibres in the infected mice than in the controls. Denervation of the myenteric plexus may decrease the content of tachykinins (TK) and VIP in animals infected with T. cruzi. Such reduction in TK and VIP activity could be related to the disturbances in intestinal motility observed in the chronic phase of Chagas disease.

Vasoactive-intestinal-peptide- and substance-P-immunoreactive nerve fibres in the myenteric plexus of mouse colon during the chronic phase ofTrypanosoma cruziinfection

The distribution of a tachykinin (substance P) and vasoactive intestinal peptide (VIP) and the number and morphology of the large granular vesicles (LGV) in the myenteric plexus of the colons of mice were investigated. Six of the 12 young, male, Swiss mice studied had been inoculated with the Y strain of Trypanosoma cruzi 2 months previously whereas the others were uninfected controls. Substance P (SP) and VIP were localized by light microscopy, using an immunohistochemical method, and LGV were counted in sections studied by electron microscopy. There were far fewer LGV and less intensely staining varicose VIP- and SP-positive nerve fibres in the infected mice than in the controls. Denervation of the myenteric plexus may decrease the content of tachykinins (TK) and VIP in animals infected with T. cruzi. Such reduction in TK and VIP activity could be related to the disturbances in intestinal motility observed in the chronic phase of Chagas disease.