Visceral afferent nerve fibers containing substance P or calcitonin gene-related peptide (CGRP) are distributed in the bladder wall, and are known to be stimulated by and then desensitized by capsaicin. Recently, there have been some reports on the effectiveness of intravesical capsaicin administration for the treatment of hypersensitive lower urinary tract disorder or neurogenic bladder. In this study, the effects of intravesical capsaicin on the substance P or CGRP immunoreactivities in the spinal dorsal horn were investigated and the mechanism of capsaicin treatment for bladder disorders was revealed. After intravesical administration of capsaicin, the substance P and CGRP immunoreactive areas were measured at the dorsal horn of L4 and S1 spinal cord. Before capsaicin treatment, the substance P immuno- reactive area was 2.61+/-0.78 x 105 mm2 in L4 and 1.66+/-0.49 x 105 mm2 in S1. The substance P immunoreactivity was markedly reduced 1~2 weeks after capsaicin treatment in both L4 and S1 spinal cord. The CGRP immunoreactive area was 1.74+/-0.52 x 105 mm2 in L4 and 1.14+/-0.69 x 105 mm2 in S1, but was not reduced after capsaicin treatment. Therefore, capsaicin administered intravesically desensitizes nerve fibers containing substance P and consequently suppresses pain and voiding reflex.
Administration, Intravesical ; Animals ; Calcitonin Gene-Related Peptide ; Capsaicin* ; Horns* ; Nerve Fibers ; Rats* ; Reflex ; Spinal Cord ; Substance P ; Urinary Bladder ; Urinary Bladder, Neurogenic ; Urinary Tract ; Visceral Afferents

Spontaneous pain, allodynia and hyperalgesia are well known phenomena following peripheral nerve or tissue injury, and it is speculated that secondary hyperalgesia and allodynia, are generally thought to depend on a hyperexcitability (sensitization) of neurons in the dorsal horn. It is supposed that the sensitization may be due to various actions of neurotransmitters (SP, CGRP, excitatory amino acids) released from the primary afferent fibers. In this study, we examined effects of the iontophoretically applied SP and CGRP on the response to EAA receptor agonists (NMDA and non-NMDA) in the WDR dorsal horn neurones and see if the effects of SP or CGRP mimic the characteristic response pattern known in various pain models. The main results are summarized as follows: 1) SP specifically potentiated NMDA response. 2) CGRP non-specifically potentiated both NMDA and AMPA responses. Potentiation of NMDA response, however, was significantly greater than that of AMPA response. 3) 50% of SP applied cells and 15.8% of CGRP applied cells showed reciprocal changes(potentiation of NMDA response and suppression of AMPA response). These results are generally consistent with the sensitization characteristics in diverse pain models and suggests that the modulatory effects of SP and CGRP on NMDA and non-NMDA (AMPA) response are, at least in part, contribute to the development of sensitization in various pain models.
Animal ; Calcitonin Gene-Related Peptide/pharmacology* ; Calcitonin Gene-Related Peptide/administration & dosage ; Excitatory Amino Acid Agonists/pharmacology* ; Iontophoresis ; Male ; N-Methylaspartate/pharmacology ; Rats ; Rats, Sprague-Dawley ; Spinal Cord/physiology ; Spinal Cord/drug effects* ; Substance P/pharmacology* ; Substance P/administration & dosage ; alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid/pharmacology

<p>BACKGROUNDProstatodynia remains a difficult clinical problem. Resiniferatoxin (RTX), an ultrapotent vanilloid, can produce a selective and long-lasting desensitization of nociception via C-fiber sensory neurons. Substance P (SP) and calcitonin gene-related peptide (CGRP) released from C-fibers are key neurotransmitters in visceral pain. In this study, we evaluated the analgesic effect of intrathecal RTX on rat prostatodynia.p><p>METHODSMale Sprague-Dawley rats were divided into 3 groups for different treatment. In group A, sham operation was preformed. In group B, 100 microl complete Freund's adjuvant (CFA) was injected into the rat's bilateral ventral prostate to induce chronic inflammation. In group C, after prostatitis formed, 50 microl 10 nmol/L RTX was injected into the rat's lumbosacral (L5-S2) vertebral canal. SP and CGRP contents in the spinal cord were investigated by immunohistochemistry and radioimmunoassay (RIA). Their transcriptional levels in dorsal root ganglion (DRG) were determined by reverse transcriptase polymerase chain reaction (RT-PCR). In addition, pelvic nerve afferent discharge was recorded to explore the neuro-electrophysiological mechanisms underlying RTX-induced effect.p><p>RESULTSSP and CGRP released in the spinal cord and their synthesis in DRG were increased significantly in response to CFA-induced chronic prostatitis, whereas this increase was effectively inhibited by intrathecal RTX. Meanwhile, pelvic nerve afferent electrical activity was enhanced significantly in rats with chronic prostatitis, but it was attenuated markedly in RTX-treated rats paralleled by the change of neuropeptides.p><p>CONCLUSIONSIntrathecal RTX administration could produce an analgesic effect on rat prostatodynia. Suppression of pelvic nerve afferent electrical activity may be a crucial mechanism underlying RTX-induced analgesia. RTX intrathecal application may present a novel analgesic strategy of prostatodynia.p>
Analgesics ; administration & dosage ; Animals ; Calcitonin Gene-Related Peptide ; analysis ; genetics ; Diterpenes ; administration & dosage ; Injections, Spinal ; Male ; Prostatitis ; drug therapy ; RNA, Messenger ; analysis ; Rats ; Rats, Sprague-Dawley ; Substance P ; analysis ; genetics

This study aimed to investigate the analgesic effect of substance P (SP) in an animal model of neuropathic pain. An experimental model of neuropathic pain, the chronic constriction injury (CCI) model, was established using ICR mice. An intravenous (i.v.) injection of SP (1 nmole/kg) was administered to the mice to examine the analgesic effects of systemic SP on neuropathic pain. Behavioral testing and immunostaining was performed following treatment of the CCI model with SP. SP attenuated mechanical allodynia in a time-dependent manner, beginning at 1 h following administration, peaking at 1 day post-injection, and decaying by 3 days post-injection. The second injection of SP also increased the threshold of mechanical allodynia, with the effects peaking on day 1 and decaying by day 3. A reduction in phospho-ERK and glial fibrillary acidic protein (GFAP) accompanied the attenuation of mechanical allodynia. We have shown for the first time that i.v. administration of substance P attenuated mechanical allodynia in the maintenance phase of neuropathic pain using von Frey’s test, and simultaneously reduced levels of phospho-ERK and GFAP, which are representative biochemical markers of neuropathic pain. Importantly, glial cells in the dorsal horn of the spinal cord (L4–L5) of SP-treated CCI mice, expressed the anti-inflammatory cytokine, IL-10, which was not seen in vehicle saline-treated mice. Thus, i.v. administration of substance P may be beneficial for improving the treatment of patients with neuropathic pain, since it decreases the activity of nociceptive factors and increases the expression of anti-nociceptive factors.
Administration, Intravenous* ; Animals ; Behavior Rating Scale ; Biomarkers ; Constriction ; Glial Fibrillary Acidic Protein ; Humans ; Hyperalgesia* ; Interleukin-10 ; Mice ; Mice, Inbred ICR ; Models, Animal ; Models, Theoretical ; Neuralgia ; Neuroglia ; Spinal Cord ; Spinal Cord Dorsal Horn ; Substance P*

The inhibitory effects of Asparagus cochinchinensis against inflammatory response induced by lipopolysaccharide (LPS), substance P and phthalic anhydride (PA) treatment were recently reported for some cell lines and animal models. To evaluate the hepatotoxicity and nephrotoxicity of A. cochinchinensis toward the livers and kidneys of ICR mice, alterations in related markers including body weight, organ weight, urine composition, liver pathology and kidney pathology were analyzed in male and female ICR mice after oral administration of 150, 300 and 600 mg/kg body weight/day saponin-enriched extract of A. cochinchinensis (SEAC) for 14 days. The saponin, total flavonoid and total phenol levels were found to be 57.2, 88.5 and 102.1 mg/g in SEAC, respectively, and the scavenging activity of SEAC gradually increased in a dose-dependent manner. Moreover, body and organ weight, clinical phenotypes, urine parameters and mice mortality did not differ between the vehicle and SEAC treated group. Furthermore, no significant alterations were measured in alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), blood urea nitrogen (BUN) and the serum creatinine (Cr) in the SEAC treated group relative to the vehicle treated group. Moreover, the specific pathological features induced by most toxic compounds were not observed upon liver and kidney histological analysis. Overall, the results of the present study suggest that SEAC does not induce any specific toxicity in the livers and kidneys of male and female ICR mice at doses of 600 mg/kg body weight/day.
Administration, Oral ; Alanine Transaminase ; Alkaline Phosphatase ; Animals ; Aspartate Aminotransferases ; Blood Urea Nitrogen ; Body Weight ; Cell Line ; Creatinine ; Female ; Humans ; Kidney ; L-Lactate Dehydrogenase ; Liver ; Male ; Mice ; Mice, Inbred ICR* ; Models, Animal ; Mortality ; Organ Size ; Pathology ; Phenol ; Phenotype ; Saponins ; Substance P

<p>OBJECTIVETo investigate the influence of Weichang Anwan on the treatment of IBS-D in model rats.p><p>METHODAnimal model of compound diarrhea was induced by a lactose enriched diet in the Wistar rat, combining with restraint stress. At first, the best cycle of taking medicine was tested. In order to decide the best cycle of taking medicine, 24 female Wistar rats were randomly divided into normal control group, model group and 60 mg x kg(1) x d(-1) weichangan group. The rate of weight increase, the rate of diarrhea, the incubation period of diarrhea and the diarrhea index were observed. And then 45 female Wistar rats randomly divided into five groups: normal control group, model group and Weichang Anwan groups of high, medium and low doses( 80, 60, 40 mg x kg(-1) x d(-1)). The mast cells in mucous membrane were observed by light microscope. The level of NO in blood serum was checked by the method of nitrate reductase. 5-HT in blood serum was detected by fluorimetry. The level of SP in colon was measured by radioimmunoassay.p><p>RESULTAfter taking Weichang Anwan for 4 days, the rate of weight increase in Weichangan group was higher than the model group's. And the rate of diarrhea was lower significantly. So the best cycle of taking medicine was 4 days. The levels of NO and 5-HT in blood serum decreased remarkably in the model group than those of the normal control group. At the same time, the amount of the mast cells and the level of SP in colon significantly increased. Compared with the model group, the levels of NO and 5-HT in blood serum increased remarkably in the groups of high doses and medium doses. Meanwhile, the amount of the mast cells and the level of SP in colon decreased significantly.p><p>CONCLUSIONWeichang Anwan has the effect of antidiarrhea. It can adjust the levels of NO and 5-HT in blood serum and can inhibit the expression of SP in colon which can active the mast cell. Weichangan can also decrease the amount of the mast cells directly.p>
Animals ; Colon ; drug effects ; immunology ; metabolism ; Disease Models, Animal ; Drugs, Chinese Herbal ; administration & dosage ; Female ; Humans ; Irritable Bowel Syndrome ; drug therapy ; immunology ; metabolism ; Mast Cells ; immunology ; Nitric Oxide ; blood ; Random Allocation ; Rats ; Rats, Wistar ; Serotonin ; blood ; Substance P ; metabolism