Ca2+ sparks and secretion in dorsal root ganglion neurons

Ca(2+) sparks as the elementary intracellular Ca(2+) release events are instrumental to local control of Ca(2+) signaling in many types of cells. Here, we visualized neural Ca(2+) sparks in dorsal root ganglion (DRG) sensory neurons and investigated possible role of DRG sparks in the regulation of secretion from the somata of the cell. DRG sparks arose mainly from type 3 ryanodine receptor Ca(2+) release channels on subsurface cisternae of the endoplasmic reticulum, rendering a striking subsurface localization. Caffeine- or 3,7-dimethyl-1-(2-propynyl)xanthine-induced store Ca(2+) release, in the form of Ca(2+) sparks, triggered exocytosis, independently of membrane depolarization and external Ca(2+). The spark-secretion coupling probability was estimated to be between 1 vesicle per 6.6 sparks and 1 vesicle per 11.4 sparks. During excitation, subsurface sparks were evoked by physiological Ca(2+) entry via the Ca(2+)-induced Ca(2+) release mechanism, and their synergistic interaction with Ca(2+) influx accounted for approximately 60% of the Ca(2+)-dependent exocytosis. Furthermore, inhibition of Ca(2+)-induced Ca(2+) release abolished endotoxin-induced secretion of pain-related neuropeptides. These findings underscore an important role for Ca(2+) sparks in the amplification of surface Ca(2+) influx and regulation of neural secretion.     

Differential effects of electrical stimulation of sciatic nerve on metabolic activity in spinal cord and dorsal root ganglion in the rat.

Electrical stimulation of the proximal stump of the transected sciatic nerve produces a frequency-dependent activation of glucose utilization, measured with the autoradiographic deoxy [14C]glucose method, in the dorsal horn of the spinal cord but produces no change in glucose utilization in the dorsal root ganglion cells. These results suggest that axon terminals and not the cell bodies are the sites of enhanced metabolic activity during increased functional activity of this pathway.     

Calorie restriction protects against apoptosis,mitochondrial oxidative stress and increased calcium signaling through inhibition of TRPV1 channel in the hippocampus and dorsal root ganglion of rats

Metabolic Brain Disease - The TRPV1 channel is activated in neurons by capsaicin, oxidative stress, acidic pH and heat factors, and these factors are attenuated by the antioxidant role of calorie...     

Transient receptor potential vanilloid subtype 1 channel mediated neuropeptide secretion and depressor effects: role of endoplasmic reticulum associated Ca2+ release receptors in rat dorsal root ganglion neurons

OBJECTIVE: This study tests the hypothesis that the transient receptor potential vanilloid subtype 1 channel induced neuropeptide secretion and depressor response are mediated by, at least in part, activation of endoplasmic reticulum associated Ca release receptors, leading to increased cytosolic Ca in dorsal root ganglion neurons. METHODS/RESULTS: Bolus injection of capsaicin (10 or 50 microg/kg), a selective transient receptor potential vanilloid subtype 1 channel agonist, into anesthetized male Wistar rats caused a dose-dependent decrease in mean arterial pressure (P < 0.05). Capsaicin (50 microg/kg)-induced depressor effects and increase in plasma calcitonin gene related peptide (CGRP) levels (-29 +/- 2 mmHg, 82.2 +/- 5.0 pg/ml) were abolished by a selective transient receptor potential vanilloid subtype 1 channel antagonist, capsazepine (3 mg/kg, -4 +/- 1 mmHg, 41.8 +/- 4.4 pg/ml, P < 0.01), and attenuated by a selective ryanodine receptor antagonist, dantrolene (5 mg/kg, -12 +/- 1 mmHg, 57.2 +/- 2.6 pg/ml, P < 0.01), but unaffected by an inhibitor of endoplasmic reticulum Ca-ATPase, thapsigargin (50 microg/kg, -30 +/- 1 mmHg, 73.8 +/- 2.3 pg/ml, P > 0.05), or an antagonist of the inositol (1,4,5)-trisphosphate receptor, 2-aminoethoxydiphenyl borate (3 mg/kg, -34 +/- 5 mmHg, 69.0 +/- 3.7 pg/ml, P > 0.05). CGRP8-37 (1 mg/kg), a selective CGRP receptor antagonist, also blocked capsaicin-induced depressor effects. In contrast, dantrolene had no effect on CGRP (1 microg/kg)-induced depressor effects. In vitro, capsaicin (0.3 micromol/l) increased intracellular Ca concentrations and CGRP release from freshly isolated sensory neurons in dorsal root ganglion (P < 0.01), which were blocked by capsazepine (10 micromol/l) and attenuated by dantrolene but not thapsigargin or 2-aminoethoxydiphenyl borate. CONCLUSION: Our results indicate that transient receptor potential vanilloid subtype 1 channel activation triggers ryanodine receptor but not inositol (1,4,5)-trisphosphate receptor dependent Ca release from endoplasmic reticulum in dorsal root ganglion neurons, leading to increased CGRP release and consequent depressor effects.     

Opiate receptor agonists regulate phosphorylation of synapsin I in cocultures of rat spinal cord and dorsal root ganglion.

Kappa opiate receptor agonists applied to cocultures of spinal cord and dorsal root ganglion neurons have been previously shown to inhibit voltage-dependent Ca2+ influx and adenylate cyclase activity. Here we describe the effect of kappa opiate receptor agonists on phosphorylation of synapsin I, a synaptic-vesicle-associated protein whose phosphorylation was shown to be regulated by cAMP and Ca2+ concentrations. Depolarization of spinal cord-dorsal root ganglion cocultured cells (by high K+ or veratridine) and the addition of forskolin (which activates adenylate cyclase) led to increased phosphorylation of synapsin I. Addition of kappa opiate agonists attenuated both the depolarization- and the forskolin-induced phosphorylation of synapsin I. This attenuation was blocked by the opiate antagonist naloxone. mu and delta opiate receptor agonists had much weaker effects on the depolarization-induced phosphorylation of synapsin I. Similarly, kappa opiate agonists decreased (by 40-60%) the high-K+- or veratridine-induced phosphorylation of synapsin I in spinal cord synaptosomes. These results show that opiate ligands modulate synapsin I phosphorylation. Moreover, the data could explain the reduction in synaptic efficacy observed after opiate treatment.     

Identification of gene expression profile of dorsal root ganglion in the rat peripheral axotomy model of neuropathic pain

Phenotypic modification of dorsal root ganglion (DRG) neurons represents an important mechanism underlying neuropathic pain. However, the nerve injury-induced molecular changes are not fully identified. To determine the molecular alterations in a broader way, we have carried out cDNA array on the genes mainly made from the cDNA libraries of lumbar DRGs of normal rats and of rats 14 days after peripheral axotomy. Of the 7,523 examined genes and expressed sequence tags (ESTs), the expression of 122 genes and 51 expressed sequence tags is strongly changed. These genes encompass a large number of members of distinct families, including neuropeptides, receptors, ion channels, signal transduction molecules, synaptic vesicle proteins, and others. Of particular interest is the up-regulation of gamma-aminobutyric acid(A) receptor alpha5 subunit, peripheral benzodiazepine receptor, nicotinic acetylcholine receptor alpha7 subunit, P2Y1 purinoceptor, Na(+) channel beta2 subunit, and L-type Ca(2+) channel alpha2delta-1 subunit. Our findings therefore reveal dynamic and complex changes in molecular diversity among DRG neurons after axotomy. Sequences reported in this paper have been deposited in the GenBank database (accession numbers BG 662484-BG 673712)     

急性坏死性胰腺炎大鼠背根神经节中P2X3的表达

目的 观察ANP大鼠痛觉敏感性的变化及脊髓背根神经节(DRG)中P2X3表达的差异.方法 牛磺胆酸钠胰腺被膜下均匀注射法制备SD大鼠ANP模型,被膜下注射等量生理盐水为假手术组,不做手术为对照组.V-fray法观察大鼠术前、术后痛阈改变,采用免疫组织化学方法检测制模后1、3、7、14 d DRG的P2X3表达.结果 ANP大鼠的缩腹频率在制模后7 d达到高峰,为65.67%,明显高于对照组(10.02%)及假手术组(0)(P＜0.01);假手术组与对照组间也有统计学差异(P＜0.05).ANP大鼠制模后1 d,DRG即出现P2X3阳性细胞,细胞数从术前的8.7±2.4增加到32.3±8.2,制模后3 d高达64.1±8.5,较假手术组的最高数21.5±4.0和对照组的高值9.5±1.9均相差显著(P＜0.01);制模后3、7、14 d假手术组P2X3阳性细胞数也显著高于对照组(P＜0.01或＜0.05).结论 ANP大鼠DRG的P2X3高表达与内脏痛觉过敏的发生相关.     

Lambert-Eaton sera reduce low-voltage and high-voltage activated Ca2+ currents in murine dorsal root ganglion neurons.

Voltage-gated Ca2+ channels are categorized as either high-voltage activated (HVA) or low-voltage activated (LVA), and a subtype (or subtypes) of HVA Ca2+ channels link the presynaptic depolarization to rapid neuro-transmitter release. Reductions in transmitter release are characteristic of the autoimmune disorder, Lambert-Eaton syndrome (LES). Because antibodies from LES patients reduce Ca2+ influx in a variety of cell types and disrupt the intramembrane organization of active zones at neuromuscular synapses, specificity of LES antibodies for the Ca2+ channels that control transmitter release has been suggested as the mechanism for disease. We tested sera from four patients with LES. Serum samples from three of the four patients reduced both the maximal LVA and HVA Ca2+ conductances in murine dorsal root ganglion neurons. Thus, even though LES is expressed as a neuromuscular and autonomic disorder, our studies suggest that Ca2+ channels may be broadly affected in LES patients. To account for the specificity of disease expression, we suggest that incapacitation of only a fraction of the Ca2+ channels clustered at active zones would severely depress transmitter release. In particular, if several Ca2+ channels in a cluster are normally required to open simultaneously before transmitter release becomes likely, the loss of a few active zone Ca2+ channels would exponentially reduce the probability of transmitter release. This model may explain why LES is expressed as a neuromuscular disorder and can account for a clinical hallmark of LES, facilitation of neuromuscular transmission produced by vigorous voluntary effort.     

Electrophysiological studies on rat dorsal root ganglion neurons after peripheral axotomy: Changes in responses to neuropeptides

The effect of three peptides, galanin, sulfated cholecystokinin octapeptide, and neurotensin (NT), was studied on acutely extirpated rat dorsal root ganglia (DRGs) in vitro with intracellular recording techniques. Both normal and peripherally axotomized DRGs were analyzed, and recordings were made from C-type (small) and A-type (large) neurons. Galanin and sulfated cholecystokinin octapeptide, with one exception, had no effect on normal C- and A-type neurons but caused an inward current in both types of neurons after sciatic nerve cut. In normal rats, NT caused an outward current in C-type neurons and an inward current in A-type neurons. After sciatic nerve cut, NT only caused an inward current in both C- and A-type neurons. These results suggest that (i) normal DRG neurons express receptors on their soma for some but not all peptides studied, (ii) C- and A-type neurons can have different types of receptors, and (iii) peripheral nerve injury can change the receptor phenotype of both C- and A-type neurons and may have differential effects on these neuron types.     

Evidence that 2-methylacetoacetate induces oxidative stress in rat brain

In the present study we investigated the effects of 2-methylacetoacetate (MAA) and 2-methyl-3-hydroxybutyrate (MHB), the major metabolites accumulating in mitochondrial 2-methylacetoacetyl-CoA thiolase (KT) and 2-methyl-3-hydroxybutyryl-CoA dehydrogenase (MHBD) deficiencies, on important parameters of oxidative stress in cerebral cortex from young rats. We verified that MAA induced lipid peroxidation (increase of thiobarbituric acid-reactive substances (TBA-RS) and chemiluminescence values), whereas MHB did not alter these parameters. MAA-induced increase of TBA-RS levels was fully prevented by free radical scavengers, indicating that free radicals were involved in this effect. Furthermore, MAA, but not MHB, significantly induced sulfhydryl oxidation, implying that this organic acid provokes protein oxidative damage. It was also observed that MAA reduced GSH, a naturally-occurring brain antioxidant, whereas MHB did not change this parameter. Furthermore, the decrease of GSH levels caused by MAA was not due to a direct oxidative action, since this organic acid did not alter the sulfhydryl content of a commercial solution of GSH in a cell free medium. Finally, MAA and MHB did not raise nitric oxide production. The data indicate that MAA induces oxidative stress in vitro in cerebral cortex. It is presumed that this pathomechanism may be involved in the brain damage found in patients affected by KT deficiency.     

Selenium prevents interferon-gamma induced activation of TRPM2 channel and inhibits inflammation,mitochondrial oxidative stress,and apoptosis in microglia

Microglia as the primary immune cells of brain act protective effects against injuries and infections in the central nervous system. Inflammation via excessive Ca²⁺ influx and oxygen radical species (ROS) generation is a known factor in many neurodegenerative disorders. Importantly, the Ca²⁺ permeable TRPM2 channel is activated by oxidative stress. Thus, TRPM2 could provide the excessive Ca²⁺ influx in the microglia. Although TRPM2 expression level is high in inflammatory cells, the interplay between mouse microglia and TRPM2 channel during inflammation is not fully identified. Thus, it is important to understand the mechanisms and factors involved in order to enhance neuronal regeneration and repair. The data presented here indicate that TRPM2 channels were activated in microglia cells by interferon-gamma (IFNγ). The IFNγ treatment further increased apoptosis (early and late) and cytokine productions (TNF-α, IL-1β, and IL-6) which were due to increased lipid peroxidation and ROS generations as well as increased activations of caspase −3 (Casp-3) and − 9 (Casp-9). However, selenium treatment diminished activations of TRPM2, cytokine, Casp-3, and Casp-9, and levels of lipid peroxidation and mitochondrial ROS production in the microglia that were treated with IFNγ. Moreover, addition of either PARP1 inhibitors (PJ34 or DPQ) or TRPM2 blockers (2-APB or ACA) potentiated the modulator effects of selenium. These results clearly suggest that IFNγ leads to TRPM2 activation in microglia cells; whereas, selenium prevents IFNγ-mediated TRPM2 activation and cytokine generation. Together the interplay between IFNγ released from microglia cells is importance in brain inflammation and may affect oxidative cytotoxicity in the microglia.

Summary of pathways involved in IFNγ-induced TRPM2 activation and microglia death through excessive reactive oxygen species (ROS): Modulator role of selenium (Se). The IFNγ causes the microglia activation. Nudix box domain of TRPM2 is sensitive to ROS. The ROS induces DNA damage and ADPR-ribose (ADPR) production in the nucleus via PARP1 enzyme activation. ADPR and ROS-induced TRPM2 activation stimulates excessive Ca²⁺ influx. ROS are produced in the mitochondria through the increase of free cytosolic Ca²⁺ (via TRPM2 activation) by the IFNγ treatment, although they are diminished by the TRPM2 channel blocker (ACA and 2-APB) and PARP1 inhibitor treatments. The main mechanism in the cell death and inflammatory effects of IFNγ is mediated by stimulation of ROS-mediated caspase (caspase −3 and − 9) activations and cytokine production (TNF-α, IL-1β, and IL-6) via TRPM2 activation, respectively. The apoptotic, inflammatory, and oxidant actions of IFNγ are modulated through TRPM2 inhibition by the Se treatment

     

Prolactin prevents acute stress-induced hypocalcemia and ulcerogenesis by acting in the brain of rat

Stress causes hypocalcemia and ulcerogenesis in rats. In rats under stressful conditions, a rapid and transient increase in circulating prolactin (PRL) is observed, and this enhanced PRL induces PRL receptors (PRLR) in the choroid plexus of rat brain. In this study we used restraint stress in water to elucidate the mechanism by which PRLR in the rat brain mediate the protective effect of PRL against stress-induced hypocalcemia and ulcerogenesis. We show that rat PRL acts through the long form of PRLR in the hypothalamus. This is followed by an increase in the long form of PRLR mRNA expression in the choroid plexus of the brain, which provides protection against restraint stress in water-induced hypocalcemia and gastric erosions. We also show that PRL induces the expression of PRLR protein and corticotropin-releasing factor mRNA in the paraventricular nucleus. These results suggest that the PRL levels increase in response to stress, and it moves from the circulation to the cerebrospinal fluid to act on the central nervous system and thereby plays an important role in helping to protect against acute stress-induced hypocalcemia and gastric erosions.     

Changes in sensory neuropeptides in dorsal root ganglion and spinal cord of spontaneously diabetic BB rats

This study examined the experession of the sensory neuropeptides, calcitonin gene-related peptide (CGRP) and substance P (SP), in the lumbar 4 and 5 dorsal root ganglion (DRG) and spinal cord of spontaneously diabetic BB rats and non-diabetic controls using quantitative immunohistochemical analysis. In both animal groups immunoreactivities for CGRP and SP were widely distributed within the neurons of DRG and in nerve fibres of the dorsal spinal cord. Image analysis of each neuropeptide subpopulation in the DRG showed that in diabetic rats the cell diameter of immunostained CGRP neurons was significantly decreased compared with controls, while no difference could be found for SP-immunoreactive (IR) neurons. The decrease in the CGRP-IR cell diameter appeared to occur mainly in medium to large neurons (30–50 m diameter; 2.2% controls, <1% diabetes), this change being parallel to an increased frequency of small-size neurons (<20 m diameter) in diabetic rats (62% controls, 69% diabetes;P<0.05). However, there was no statistical difference in the total number of cells immunostained for either CGRP or SP between control and diabetic rats. The ratio of CGRP or SP neurons compared to total cells in the ganglion was similar in control and diabetic groups. No difference could be observed for peptide immunoreactivity in the dorsal and ventral horns of either control or diabetic animals. The observed changes of perikaryal size in diabetic rats might relate to the reduced axonal calibre and conduction velocity observed in these animals, and indicate that subpopulations of sensory neurons are affected differently by diabetes.     

Effect of gbpapentin on the expression of Nrf2 in dorsal root ganglion neurons of diabetic neuropathic pain rats

<正>Objective To investigate the effect of systemic administration of gabapentin on the expression of Nrf2 in dorsal root ganglion neurons in a rat model of diabetic neuropathic pain (DNP). Methods 60 male SD rats weighing 200-220 g were randomly divided into 4groups (n=15 each):control group (group C),DNP     

Electromagnetic radiation (Wi-Fi) and epilepsy induce calcium entry and apoptosis through activation of TRPV1 channel in hippocampus and dorsal root ganglion of rats

Incidence rates of epilepsy and use of Wi-Fi worldwide have been increasing. TRPV1 is a Ca²⁺ permeable and non-selective channel, gated by noxious heat, oxidative stress and capsaicin (CAP). The hyperthermia and oxidant effects of Wi-Fi may induce apoptosis and Ca²⁺ entry through activation of TRPV1 channel in epilepsy. Therefore, we tested the effects of Wi-Fi (2.45 GHz) exposure on Ca²⁺ influx, oxidative stress and apoptosis through TRPV1 channel in the murine dorsal root ganglion (DRG) and hippocampus of pentylentetrazol (PTZ)-induced epileptic rats. Rats in the present study were divided into two groups as controls and PTZ. The PTZ groups were divided into two subgroups namely PTZ + Wi-Fi and PTZ + Wi-Fi + capsazepine (CPZ). The hippocampal and DRG neurons were freshly isolated from the rats. The DRG and hippocampus in PTZ + Wi-Fi and PTZ + Wi-Fi + CPZ groups were exposed to Wi-Fi for 1 hour before CAP stimulation. The cytosolic free Ca²⁺, reactive oxygen species production, apoptosis, mitochondrial membrane depolarization, caspase-3 and ?9 values in hippocampus were higher in the PTZ group than in the control although cell viability values decreased. The Wi-Fi exposure induced additional effects on the cytosolic Ca²⁺ increase. However, pretreatment of the neurons with CPZ, results in a protection against epilepsy-induced Ca²⁺ influx, apoptosis and oxidative damages. In results of whole cell patch-clamp experiments, treatment of DRG with Ca²⁺ channel antagonists [thapsigargin, verapamil + diltiazem, 2-APB, MK-801] indicated that Wi-Fi exposure induced Ca²⁺ influx via the TRPV1 channels. In conclusion, epilepsy and Wi-Fi in our experimental model is involved in Ca²⁺ influx and oxidative stress-induced hippocampal and DRG death through activation of TRPV1 channels, and negative modulation of this channel activity by CPZ pretreatment may account for the neuroprotective activity against oxidative stress.     

Involvement of oxidative stress-induced abnormalities in ceramide and cholesterol metabolism in brain aging and Alzheimer's disease

Alzheimer's disease (AD) is an age-related disorder characterized by deposition of amyloid beta-peptide (Abeta) and degeneration of neurons in brain regions such as the hippocampus, resulting in progressive cognitive dysfunction. The pathogenesis of AD is tightly linked to Abeta deposition and oxidative stress, but it remains unclear as to how these factors result in neuronal dysfunction and death. We report alterations in sphingolipid and cholesterol metabolism during normal brain aging and in the brains of AD patients that result in accumulation of long-chain ceramides and cholesterol. Membrane-associated oxidative stress occurs in association with the lipid alterations, and exposure of hippocampal neurons to Abeta induces membrane oxidative stress and the accumulation of ceramide species and cholesterol. Treatment of neurons with alpha-tocopherol or an inhibitor of sphingomyelin synthesis prevents accumulation of ceramides and cholesterol and protects them against death induced by Abeta. Our findings suggest a sequence of events in the pathogenesis of AD in which Abeta induces membrane-associated oxidative stress, resulting in perturbed ceramide and cholesterol metabolism which, in turn, triggers a neurodegenerative cascade that leads to clinical disease.     

Modulation of oxidative stress-induced changes in hypertension and atherosclerosis by antioxidants

An imbalance between reactive oxygen species and antioxidant reserve, referred to as oxidative stress, results in the altered structure and function of proteins, lipids and DNA. Oxidative stress is associated with hypertension and atherosclerosis, but it is unknown whether it is a causative or resultant factor. The authors suggest that insulin resistance is the key element in the pathogenesis of these diseases, and leads to abnormal glucose and lipid metabolism with an increase in reactive aldehydes. These aldehydes react with the sulfhydryl and amino groups of proteins to form advanced glycation end products, adversely affecting body proteins, including antioxidant enzymes. This leads to oxidative stress. Advanced glycation end products and reactive oxygen species perpetuate a pro-oxidant state, producing the changes that are characteristic of hypertension and atherosclerosis. Antioxidants have been shown to modulate these changes. An ideal therapy for these diseases includes antioxidants, which attenuate insulin resistance, the source of oxidative stress.     

Mitochondrial oxidative stress-induced brain and hippocampus apoptosis decrease through modulation of caspase activity,Ca2+ influx and inflammatory cytokine molecular pathways in the docetaxel-treated mice by melatonin and selenium treatments

Docetaxel (DOCE) is widely used to treat several types of glioblastoma. Adverse effects DOCE seriously limit its clinical use in several tissues. Its side effects on brain cortex and hippocampus have not been clarified yet. Limited data indicated a protective effect of melatonin (MLT) and selenium (SELEN) on DOCE-induced apoptosis, Ca²⁺ influx and mitochondrial reactive oxygen species (ROS) in several tissues except brain and hippocampus. The purpose of this study is to discover the protective effect of MLT and SELEN on DOCE-induced brain and hippocampus oxidative toxicity in mice. MLT and SELEN pretreatments significantly ameliorated acute DOCE-induced mitochondrial ROS production in the hippocampus and brain tissues by reducing levels of lipid peroxidation, intracellular ROS production and mitochondrial membrane depolarization, while increasing levels of total antioxidant status, glutathione, glutathione peroxidase, MLT, α-tocopherol, γ-tocopherol, vitamin A, vitamin C and β-carotene in the tissues. Furthermore, MLT and SELEN pretreatments increased cell viability and TRPM2 channel activation in the hippocampus and brain followed by decreased activations of TNF-α, IL-1β, IL-6, and caspase ?3 and???9, suggesting a suppression of calcium ion influx, apoptosis and inflammation responses. However, modulator role of SELEN on the values in the tissues is more significant than in the MLT treatment. MLT and SELEN prevent DOCE-induced hippocampus and brain injury by inhibiting mitochondrial ROS and cellular apoptosis through regulating caspase ?3 and???9 activation signaling pathways. MLT and SELEN may serve as potential therapeutic targets against DOCE-induced toxicity in the hippocampus and brain.

     

集落刺激因子-1自背根节向脊髓转运在长春新碱诱导神经病理性疼痛中的作用

目的探讨集落刺激因子-1(CSF-1)自背根节向脊髓转运在长春新碱诱导神经病理性疼痛中的作用及其机制。方法健康雄性SD大鼠30只,采用随机数表法分为3组:正常对照组、化疗所致神经病理性疼痛(CINP)组(隔日腹腔注射长春新碱建立CINP模型)和背根切断(DRR)组(切断腰4～6背根后,建立CINP模型),每组10只。采用机械缩足反射阈值(MWT)和热缩足反射潜伏期(TWL)评价大鼠机械痛敏和热痛敏。Western blotting检测背根节和脊髓CSF-1、以及离子钙结合适配器分子1(Iba1)表达;免疫荧光化学法检测脊髓Iba1表达;逆转录-聚合酶链反应法检测背根节和脊髓CSF-1 mRNA表达。采用SPSS 19.0软件进行数据处理。组间比较采用单因素方差分析。结果与对照组比较,腹腔注射长春新碱3、5、7 d后,CINP组和DRR组大鼠的MWT和TWL均显著降低(P0.01);与CINP组比较,DRR组大鼠在给药3、5、7 d后的MWT和TWL均显著升高(P0.01)。与对照组相比,CINP组大鼠背根节[(0.21±0.04)和(1.08±0.15)]和脊髓CSF-1蛋白表达[(0.22±0.05)和(1.17±0.14)]、脊髓Iba1蛋白表达[(100±0)%和(250±19)%]、背根节CSF-1 mRNA表达[(0.20±0.05)和(1.02±0.10)]均显著升高(P0.05);与CINP组相比,DRR组大鼠脊髓CSF-1蛋白表达[(1.17±0.14)和(0.45±0.06)]、脊髓Iba1蛋白表达[(250±19)%和(130±16)%]均显著降低(P0.05)。结论长春新碱诱导CINP的机制可能与CSF-1自背根节向脊髓转运激活小胶质细胞有关。