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1.

Background

Pancreatic neuritis is a histopathological hallmark of pancreatic neuropathy and correlates to abdominal neuropathic pain sensation in pancreatic adenocarcinoma (PCa) and chronic pancreatitis (CP). However, inflammatory cell subtypes that compose pancreatic neuritis and their correlation to the neuropathic pain syndrome in PCa and CP are yet unknown.

Methods

Inflammatory cells within pancreatic neuritis lesions of patients with PCa (n = 20) and CP (n = 20) were immunolabeled and colorimetrically quantified with the pan-leukocyte marker CD45, with CD68 (macrophages), CD8 (cytotoxic T-lymphocytes), CD4 (T-helper cells), CD20 (B-lymphocytes), NCL-PC (plasma cells), neutrophil elastase, PRG2 (eosinophils), anti-mast cell (MC) tryptase and correlated to pain sensation. Perineural mast cell subtypes were analyzed by double immunolabeling with MC chymase. Expression and neural immunoreactivity of protease-activated receptor type 1 (PAR-1) and type 2 (PAR-2) were analyzed in PCa and CP and correlated to pain status of the patients.

Results

In PCa and CP, nerves were predominantly infiltrated by cytotoxic T-lymphocytes (PCa: 35% of all perineural inflammatory cells, CP: 33%), macrophages (PCa: 39%, CP: 33%) and MC (PCa: 21%, CP: 27%). In both entities, neuropathic pain sensation was associated with a specific increase of perineural MC (PCa without pain: 14% vs. PCa with pain: 31%; CP without pain: 19% vs. CP with pain: 34%), not affecting the frequency of other inflammatory cell subtypes. The vast majority of these MC contained MC chymase. PAR-1 and PAR-2 expression did not correlate to the pain sensation of PCa and CP patients.

Conclusion

Pancreatic neuritis in PC and CP is composed of cytotoxic T-lymphocytes, macrophages and MC. The specific enrichment of MC around intrapancreatic nerves in neuropathic pain due to PCa and CP suggests the presence of MC-induced visceral hypersensitivity in the pancreas. Therefore, pancreatic and enteric neuropathies seem to share a similar type of neuro-immune interaction in the generation of visceral pain.  相似文献   

2.
The pigment-protein complexes CP43 and CP47 transfer excitation energy from the peripheral antenna of photosystem II toward the photochemical reaction center. We measured the excitation dynamics of the chlorophylls in isolated CP43 and CP47 complexes at 77 K by time-resolved absorbance-difference and fluorescence spectroscopy. The spectral relaxation appeared to occur with rates of 0.2-0.4 ps and 2-3 ps in both complexes, whereas an additional relaxation of 17 ps was observed only in CP47. Using the 3.8-A crystal structure of the photosystem II core complex from Synechococcus elongatus (A. Zouni, H.-T. Witt, J. Kern, P. Fromme, N. Krauss, W. Saenger, and P. Orth, 2001, Nature, 409:739-743), excitation energy transfer kinetics were calculated and a Monte Carlo simulation of the absorption spectra was performed. In both complexes, the rate of 0.2-0.4 ps can be ascribed to excitation energy transfer within a layer of chlorophylls near the stromal side of the membrane, and the slower 2-3-ps process to excitation energy transfer to the calculated lowest excitonic state. We conclude that excitation energy transfer within CP43 and CP47 is fast and does not contribute significantly to the well-known slow trapping of excitation energy in photosystem II.  相似文献   

3.
The following phenomena were observed when relative contraction and relaxation effects of ATP and creatine phosphate (CP) were studied in rabbit psoas muscle glycerinated fiber bundles containing native creatine phosphokinase (CPK) and ATPase activities: (1) nucleotide was absolutely necessary for contraction; (2) in the presence of a small amount of ADP (250 μM), physiological concentration of CP (10 mM) produced faster and stronger contraction and faster, more complete, relaxation than equimolar or higher concentrations of ATP; (3) if the nucleotide was in the form of ATP, the nucleotide Km for contraction was about 1.5 mM; (4) if the nucleotide was in the form of ADP, the nucleotide Km for contraction at physiological concentration of CP (10 mM) was 0.076 to 1.18 mM depending upon the order of addition of ADP and CP; (5) the apparent Km for CP for contraction was 2.67 mM independent of sequence of addition of ADP and CP.  相似文献   

4.

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is a common male urological disease characterized by chronic pelvic pain. Extracorporeal shock wave therapy (ESWT) has been used to treat patients with CP/CPPS, but the parameters used by ESWT are not uniformly determined. Herein, this study aims to assess the effects of ESWT with different energy flux densities on pelvic pain in CP/CPPS rats and to explore the mechanisms. A rat model of CP/CPPS was induced by intraprostatic injection of 1% carrageenan. ESWT with different energy flux densities (0.09, 0.20, 0.30, 0.40 mJ/mm2) was applied in the pelvic region of CP/CPPS rats once a week for 4 weeks. The results showed that compared with the other energy flux densities (0.09, 0.30, and 0.40 mJ/mm2), ESWT with 0.20 mJ/mm2 exhibited a more powerful effect in alleviating pelvic pain and prostate damage. The therapeutic effect is associated with the reduction of the number of total and degranulated mast cells. Collectively, ESWT with 0.20 mJ/mm2 achieved the optimal therapeutic effect in alleviating pelvic pain in CP/CPPS rats.

  相似文献   

5.
In order to simulate dielectric relaxation spectra (DRS) of budding yeast cells (Saccharomyces cerevisiae) in suspension, the complex polarization factor (Clausius-Mossotti factor) beta for a single cell and the complex permittivity of a cell suspension epsilon(sus)* were calculated with a doublet-shaped model (model RD), in which two spheres were connected with a part of a ring torus, using the boundary element method. The beta values were represented by a diagonal tensor consisting of components beta(z) parallel to the rotation axis (z axis) and beta(h) in a plane (h plane) perpendicular to the axis. The epsilon(sus)* values were calculated from the complex permittivity of the suspending medium epsilon(a)* and the components of beta. The calculation was compared with that of a conventional prolate spheroid model (model CP). It was found that model CP could be used as a first approximation to model RD. However, differences existed in beta(z) between models RD and CP; beta(z) showed three relaxation terms in the case of model RD in contrast with two terms in model CP. Narrowing the junction between the two spheres in model RD markedly decreased the characteristic frequency of one of the relaxation terms in beta(z). This suggests that the structure of the junction can be estimated from DRS. Effects of the shape change from model RD to a two-sphere model (model RD without the junction) were also examined. The behavior of beta(z) in the two-sphere model, the relaxation intensity of which was much lower than model RD, was quite similar to that in a single-sphere model. These simulations were consistent with the experimental observations of the dielectric behavior of the yeast cells during cell cycle progression.  相似文献   

6.
According to fear-avoidance models of pain perception, heightened fear of pain may increase disruptive effects of pain; however, the extent to which this affects self-reported pain severity versus physiological indices of pain is not well delineated. The current study examined self-report measures and physiological indices of pain during a cold pressor (CP) task. Individual differences in fear of pain and pain catastrophizing were also assessed via questionnaire. The primary aim of the current study was to examine the extent to which individual differences associated with fear and catastrophizing in response to pain influences subjective and physiological measures of pain. A secondary aim was to examine gender differences associated with response to pain. Average subjective pain ratings were higher for females than males. In contrast, males exhibited higher systolic and diastolic reactivity in response to the CP task relative to females, as well as failure to fully recover to baseline levels. Follow-up correlational analyses revealed that subjective pain ratings were positively associated with fear of pain in both sexes, but were not associated with cardiovascular indices. These results suggest that fear of pain and pain catastrophizing do not influence cardiovascular responses to induced pain. Further research is necessary in order to determine whether these gender differences in blood pressure and heart rate response profiles are due to biological or psychosocial influences. Results support the notion that fear of pain increases subjective pain ratings, but does not influence cardiovascular responses during CP pain-induction.  相似文献   

7.
Pain is the hallmark of patients with chronic prostatitis (CP) and chronic pelvic pain syndrome (CPPS). Despite numerous hypotheses, the etiology and pathogenesis remain unknown. To better understand CP/CPPS, we used a murine experimental autoimmune prostatitis model to examine the development, localization, and modulation of pelvic pain. Pelvic pain was detected 5 days after antigen instillation and was sustained beyond 30 days, indicating the development of chronic pain. The pain was attenuated by lidocaine treatment into the prostate, but not into the bladder or the colon, suggesting that pain originated from the prostate. Experimental autoimmune prostatitis histopathology was confined to the prostate with focal periglandular inflammatory infiltrates in the ventral, dorsolateral, and anterior lobes of the mouse prostate. Inflammation and pelvic pain were positively correlated and increased with time. Morphologically, the dorsolateral prostate alone showed significantly increased neuronal fiber distribution, as evidenced by increased protein gene product 9.5 expression. Pelvic pain was attenuated by treatment with the neuromodulator gabapentin, suggesting spinal and/or supraspinal contribution to chronic pain. These results provide the basis for identifying mechanisms that regulate pelvic pain and the testing of therapeutic agents that block pain development in CP/CPPS.  相似文献   

8.
Cyanobacterium Anacystis nidulans R2, Synechocystis sp. PCC 6803 (wild-type strain and mutants Delta2 and Delta3 lacking PSII and PSI, respectively), and Synechocystis sp. BO 9201 synthesize the pigment--protein complex CP36 (CPIV-4, CP43') under iron deficiency in the medium. Accumulation of CP36 is accompanied by structural reorganizations in the photosynthetic membranes. Integrating mean times of excitation relaxation (quenching) are 2.2 nsec (CP36), 1 nsec (PSI), and 420 psec (PSII in Fm state). The energy migration between CP36 and the photosystems can be described by a model of a one-layer ring of CP36 around core-complexes. The excitation from CP36 to PSI is transferred within <10 psec. The energy transfer from CP36 to PSII occurs during 170 psec. Cells with low content of CP36 probably contain only a latent fraction of unbound to phycobilisomes PSII which is the analog of PSIIbeta of higher plants. In PSI there are four binding sites for CP36 monomers per RC. PSII can bind up to 32 molecules of CP36 per RC. Cells with a large amount of CP36 contain monomer form of PSII core-complex which can bind eight tetramers of CP36 (8 binding sites). In conditions of iron deficiency only one monomer of a dimer PSII core-complex is destroyed and released chlorophyll is accumulated in CP36. Accumulation of CP36 in A. nidulans cells can be accompanied by membrane stacking which is similar to the stacking in chlorophyll b-containing organisms. The stacking can occur in the region of localization of PSII latent fraction bound to CP36. The membrane stacking shields PSII stromal surfaces from the aqueous phase for activation of electron transfer on the acceptor side of PSII.  相似文献   

9.
The study investigated the differences in pain perception in highly (Highs) and low (Lows) hypnotizable patients with chronic benign pain undergoing hypnotic suggestions of analgesia. Self reports of pain intensity were collected in different groups of fibromyalgic patients: (1) Highs and Lows during pre-hypnosis, neutral hypnosis, suggestions for analgesia, posthypnotic conditions; (2) Lows during suggestions for analgesia administered after a mental stress instead of neutral hypnosis; (3) healthy Lows receiving nociceptive stimulation during hypnotic relaxation and suggestions of analgesia. The results showed that Highs and Lows differed in their response to suggestions, but significant analgesia was reported also by Lows. These individuals did not report any difference in pain perception between the sessions including mental stress and hypnotic relaxation. No change in pain perception was observed in healthy Lows during nociceptive stimulation associated with relaxation and suggestions for analgesia. In conclusion, the presence of chronic pain seems to be responsible for the paradoxical response of non hypnotizable patients to hypnotic suggestions.  相似文献   

10.
Chronic pancreatitis (CP) is a relatively common disorder, characterized by glandular insufficiency and chronic, often intractable, pain. The mechanism of pain in CP is poorly understood. We have previously developed a model of trinitrobenzene sulphonic acid (TNBS)-induced CP that results in nociceptive sensitization in rats. This study was designed to examine changes in the excitability and alteration of voltage-gated K(+) currents of dorsal root ganglia (DRG) neurons innervating the pancreas. CP was induced in adult rats by an intraductal injection of TNBS. DRG neurons innervating the pancreas were identified by 1,1'-dioleyl-3,3,3',3-tetramethylindocarbocyanine methanesulfonate fluorescence labeling. Perforated patch-clamp recordings were made from acutely dissociated DRG neurons from control and TNBS-treated rats. Pancreas-specific DRG neurons displayed more depolarized resting potentials in TNBS-treated rats than those in controls (P < 0.02). Some neurons from the TNBS-treated group exhibited spontaneous firings. TNBS-induced CP also resulted in a dramatic reduction in rheobase (P < 0.05) and a significant increase in the number of action potentials evoked at twice rheobase (P < 0.05). Under voltage-clamp conditions, neurons from both groups exhibited transient A-type (I(A)) and sustained outward rectifier K(+) currents (I(K)). Compared with controls, the average I(A) but not the average I(K) density was significantly reduced in the TNBS-treated group (P < 0.05). The steady-state inactivation curve for I(A) was displaced by approximately 20 mV to more hyperpolarized levels after the TNBS treatment. These data suggest that TNBS treatment increases the excitability of pancreas-specific DRG neurons by suppressing I(A) density, thus identifying for the first time a specific molecular mechanism underlying chronic visceral pain and sensitization in CP.  相似文献   

11.
In 1995, the NIH (National Institutes of Health, USA) proposed a new classification of chronic prostatitis (CP), no longer considered in the strict framework of the prostate, but based on the concept of pelvic pain. This classification introduced the term chronic pelvic pain syndrome (CPPS). The definition of this syndrome indicates that pain is sometimes associated with sexual disorders. Many surveys have demonstrated the considerable prevalence of CP/CPPS and have confirmed the impact of these diseases on quality of life, but only limited epidemiological data concerning the links between CP/CPPS and sexuality are available at the present time. The pathophysiology of sexual dysfunction associated with CP/CPPS (alteration of desire, erectile dysfunction and premature ejaculation) also remains poorly elucidated. A psychological factor is very probably involved, but many uncertainties persist concerning the other mechanisms possibly involved.  相似文献   

12.
Capping protein (CP) is a ubiquitously expressed, heterodimeric 62-kDa protein that binds the barbed end of the actin filament with high affinity to block further filament elongation. Myotrophin (V-1) is a 13-kDa ankyrin repeat-containing protein that binds CP tightly, sequestering it in a totally inactive complex in vitro. Here, we elucidate the molecular interaction between CP and V-1 by NMR. Specifically, chemical shift mapping and intermolecular paramagnetic relaxation enhancement experiments reveal that the ankyrin loops of V-1, which are essential for V-1/CP interaction, bind the basic patch near the joint of the α tentacle of CP shown previously to drive most of the association of CP with and affinity for the barbed end. Consistently, site-directed mutagenesis of CP shows that V-1 and the strong electrostatic binding site for CP on the barbed end compete for this basic patch on CP. These results can explain how V-1 inactivates barbed end capping by CP and why V-1 is incapable of uncapping CP-capped actin filaments, the two signature biochemical activities of V-1.  相似文献   

13.

Background

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) has been treated with several different interventions with limited success. This meta-analysis aims to review all trials reporting on therapeutic intervention for CP/CPPS using the National Institutes of Health-Chronic Prostatitis Symptom Index (NIH-CPSI).

Methods

We searched Medline, PubMed, the Cochrane Pain, Palliative & Supportive Care Trials, the Cochrane Register of Controlled Trials, CINAHL, ClinicalTrials.gov, and the NIDDK website between 1947 and December 31, 2011 without language or study type restrictions. All RCTs for CP/CPPS lasting at least 6 weeks, with a minimum of 10 participants per arm, and using the NIH-CPSI score, the criterion standard for CP/CPPS, as an outcome measure were included. Data was extracted from each study by two independent reviewers. Gillbraith and I-squared plots were used for heterogeneity testing and Eggers and Peters methods for publication bias. Quality was assessed using a component approach and meta-regression was used to analyze sources of heterogeneity.

Results

Mepartricin, percutaneous tibial nerve stimulation (PTNS), and triple therapy comprised of doxazosin + ibuprofen + thiocolchicoside (DIT) resulted in clinically and statistically significant reduction in NIH-CPSI total score. The same agents and aerobic exercise resulted in clinically and statistically significant NIH-CPSI pain domain score reduction. Acupuncture, DIT, and PTNS were found to produce statistically and clinically significant reductions in the NIH-CPSI voiding domain. A statistically significant placebo effect was found for all outcomes and time analysis showed that efficacy of all treatments increased over time. Alpha-blockers, antibiotics, and combinations of the two failed to show statistically or clinically significant NIH-CPSI reductions.

Conclusion

Results from this meta-analysis reflect our current inability to effectively manage CP/CPPS. Clinicians and researchers must consider placebo effect and treatment efficacy over time and design studies creatively so we can more fully elucidate the etiology and role of therapeutic intervention in CP/CPPS.  相似文献   

14.
Glycerinated rabbit psoas muscle fibers containing native CPK, ATPase, and myokinase activities were used and isometric contraction and relaxation responses to either ADP or ATP + CP or to ATP alone in the presence and absence of P1, P5-di(adenosine-5'-pentaphosphate), a myokinase inhibitor, were compared. In previous (14) work it was shown that CP generated more efficient and faster contraction and relaxation of glycerinated muscle fibers than ATP. The present work deals with the role of myokinase in the differential response of fibers to CP and ATP. Inhibition of the myokinase activity of these fibers caused slight diminution of the rate of contraction at physiological concentrations of ATP. Uninhibited fibers were not able to reach maximum contraction, because the tension began to drop gradually even in the presence of Ca2+. Addition of Ap5A permitted maximum contraction and the ability to stay at the contracted state. In the case of CP + adenosine nucleotides (ATP or ADP), myokinase activity decreased the rate of tension development which was statistically significant after 5-7 sec of contraction. Thus, a higher tension was obtainable when myokinase was inhibited. At high concentration of adenine nucleotides (greater than 2 mM) and in the absence of Ap5A, not only the maximum tension never was reached, but a spontaneous drop in tension was observed before addition of EGTA, as was seen with ATP alone. Relaxation was faster and more complete in the presence of uninhibited myokinase activity except that the ADP was low (125 mM). These observations provide further evidence for a close functional interaction of these three enzymes in the mechanism of contraction and relaxation, giving further support to the notion of the creatine-phosphocreatine energy shuttle.  相似文献   

15.

Background

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is one of the risk factors of impaired male fertility potential. Studies have investigated the effect of CP/CPPS on several semen parameters but have shown inconsistent results. Hence, we performed a systematic literature review and meta-analysis to assess the association between CP/CPPS and basic semen parameters in adult men.

Methods

Systematic literature searches were conducted with PubMed, EMBASE and the Cochrane Library up to August 2013 for case-control studies that involved the impact of CP/CPSS on semen parameters. Meta-analysis was performed with Review Manager and Stata software. Standard mean differences (SMD) of semen parameters were identified with 95% confidence intervals (95% CI) in a random effects model.

Results

Twelve studies were identified, including 999 cases of CP/CPPS and 455 controls. Our results illustrated that the sperm concentration and the percentage of progressively motile sperm and morphologically normal sperm from patients with CP/CPPS were significantly lower than controls (SMD (95% CI) −14.12 (−21.69, −6.63), −5.94 (−8.63, −3.25) and −8.26 (−11.83, −4.66), respectively). However, semen volume in the CP/CPPS group was higher than in the control group (SMD (95% CI) 0.50 (0.11, 0.89)). There was no significant effect of CP/CPPS on the total sperm count, sperm total motility, and sperm vitality.

Conclusions

The present study illustrates that there was a significant negative effect of CP/CPPS on sperm concentration, sperm progressive motility, and normal sperm morphology. Further studies with larger sample sizes are needed to better illuminate the negative impact of CP/CPPS on semen parameters.  相似文献   

16.
The blocking of the creatinphosphokinase by 1-fluoro-2,4-dinitrobenzene (FDNB) allows to investigate the relationship between ATP-supply, contractility and relaxability of the frog's myocardium. In isotonically working isolated ventricles of frogs the time of work, systolic and diastolic volume, velocity of contraction and relaxation as well as the levels of CP, ATP, ADP and AMP were measured at different intervals until termination of each experiment. CP shows a small variation, ATP decreases to 60% and ADP + AMP increase for the same amount under FDNB during the development of a slight inhibition of contractility and a continuously growing inhibition and retardation of relaxation until systolic arrest. ATP content and volume of relaxation correlated strictly. The contracture and the diminished contractility are caused by the decrease of ATP, producing a lack of substrate for Ca transport and actin-myosin-ATPase. This models the course of events during an insufficiency like in angina pectoris and in myocardial infarction.  相似文献   

17.
《Free radical research》2013,47(11):941-949
Abstract

Chronic pancreatitis (CP) is characterized by pain, and exocrine and endocrine insufficiency of pancreas. Several hypotheses have been put forward to explain the hitherto partially understood pathophysiology of CP. In the past decade, animal and clinical studies have suggested that an increased chronic oxidative stress (OS) plays a key role in pathophysiology of CP and perpetuates its clinical and histological symptoms (pain and fibrosis–necrosis, respectively). Mounting OS in pancreatic acinar cells is a result of overproduction of free radicals (FR) during xenobiotic metabolism. It has been shown that Phase I cytochrome P450 enzymes of xenobiotic pathway are induced when exposed to a xenobiotic overload including alcohol, tobacco, smoke and other dietary toxins, which exceeds the capacity of Phase II conjugation due to limited glutathione availability. Consequently, there is an overload of toxic metabolites as well as FR. Additionally, bioactivation of subsequently entering compounds may occur increasing their toxicity. Such an imbalance overwhelms the antioxidant capacity of the body resulting in undefended chronic OS that derails the normal physiology of pancreatic acinar cells since FR act as second messengers controlling the cellular signaling. OS hypothesis is further supported by the studies that demonstrated that antioxidant supplementation ameliorated pain. Moreover, animal studies have demonstrated a cessation of fibrotic cascade with antioxidant supplementation. In a recent large randomized controlled trial, it was demonstrated that antioxidant supplementation led to a significant reduction in pain, and also lowered the OS in patients with alcoholic or idiopathic CP.  相似文献   

18.
Chronic neck pain is a major public health problem with very few evidence-based complementary treatment options. This study aimed to test the efficacy of 12 weeks of a partner-delivered home-based cupping massage, compared to the same period of progressive muscle relaxation in patients with chronic non-specific neck pain. Patients were randomly assigned to self-directed cupping massage or progressive muscle relaxation. They were trained and asked to undertake the assigned treatment twice weekly for 12 weeks. Primary outcome measure was the current neck pain intensity (0–100 mm visual analog scale; VAS) after 12 weeks. Secondary outcome measures included pain on motion, affective pain perception, functional disability, psychological distress, wellbeing, health-related quality of life, pressure pain thresholds and adverse events. Sixty one patients (54.1±12.7 years; 73.8%female) were randomized to cupping massage (n = 30) or progressive muscle relaxation (n = 31). After treatment, both groups showed significantly less pain compared to baseline however without significant group differences. Significant effects in favor of cupping massage were only found for wellbeing and pressure pain thresholds. In conclusion, cupping massage is no more effective than progressive muscle relaxation in reducing chronic non-specific neck pain. Both therapies can be easily used at home and can reduce pain to a minimal clinically relevant extent. Cupping massage may however be better than PMR in improving well-being and decreasing pressure pain sensitivity but more studies with larger samples and longer follow-up periods are needed to confirm these results.

Trial Registration

ClinicalTrials.gov NCT01500330  相似文献   

19.
The effect of [MgADP] on relaxation from isometric tension, initiated by reducing free [Ca2+] through photolysis of the caged photolabile Ca2+ chelator diazo-2, was determined at 20 degrees C in alpha-toxin permeabilized tonic (rabbit femoral artery, Rf) and phasic (rabbit bladder, Rb) smooth muscle. In Rf, the shape of the relaxation curve was clearly biphasic, consisting of a slow "plateau" phase followed by a monotonic exponential decline with rate constant k. The duration of the plateau (d = 44 +/- 4 s, mean +/- SEM, n = 28) was well correlated (R = 0.92) with the total t1/2 of relaxation that was 66 +/- 3 s (n = 28) in the presence of 20 mM creatine phosphate (CP), and was prolonged in the absence of CP (t1/2 = 83 +/- 3 s, n = 7); addition of 100 microM MgADP further slowed relaxation (t1/2 = 132 +/- 7 s, n = 14). In Rb, a plateau was not detectable and t1/2 (= 15 +/- 2 s, n = 6) was not affected by 100 microM MgADP. In Rf the Q10 between 20 degrees C and 30 degrees C was 4.3 +/- 0.4 for d-1 and 2.8 +/- 0.3 for k (n = 8; p = 0.006). The regulatory myosin light chain (MLC20) in Rf was dephosphorylated at 0.07 +/- 0.02 s-1, from 42 +/- 3% before to 20 +/- 2% after photolysis of diazo-2, reaching basal values at a time when force had fallen by only 40%. We conclude that, in the presence of ATP, as during rigor, the affinity of dephosphorylated cross-bridges for MgADP is significantly higher in tonic than in phasic smooth muscle and contributes to the maintenance of force at low levels of phosphorylation. The MgADP dependence of the post-dephosphorylation phase of relaxation is consistent with its being rate-limited by the slow off-rate of ADP from cross-bridges that were dephosphorylated while in force-generating ADP-bound (AM*D) cross-bridge states. The fourfold faster off-rate of ADP from AM*D in the phasic, Rb, compared to tonic, Rf, smooth muscle is a major determinant of the different kinetics of relaxation in the two types of smooth muscle.  相似文献   

20.
The etiology of chronic prostatitis/chronic pelvic pain syndrome in men is unknown but may involve microbes and autoimmune mechanisms. We developed an infection model of chronic pelvic pain in NOD/ShiLtJ (NOD) mice with a clinical Escherichia coli isolate (CP-1) from a patient with chronic pelvic pain. We investigated pain mechanisms in NOD mice and compared it to C57BL/6 (B6) mice, a strain resistant to CP-1-induced pain. Adoptive transfer of CD4+ T cells, but not serum, from CP-1-infected NOD mice was sufficient to induce chronic pelvic pain. CD4+ T cells in CP-1-infected NOD mice expressed IFN-γ and IL-17A but not IL-4, consistent with a Th1/Th17 immune signature. Adoptive transfer of ex-vivo expanded IFN-γ or IL-17A-expressing cells was sufficient to induce pelvic pain in naïve NOD recipients. Pelvic pain was not abolished in NOD-IFN-γ-KO mice but was associated with an enhanced IL-17A immune response to CP1 infection. These findings demonstrate a novel role for Th1 and Th17-mediated adaptive immune mechanisms in chronic pelvic pain.  相似文献   

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