Electroacupuncture intervention of visceral hypersensitivity is involved in PAR-2-activation and CGRP-release in the spinal cord.

Electroacupuncture (EA) relieves visceral hypersensitivity (VH) with underlying inflammatory bowel diseases. However, the mechanism by which EA treats ileitis-induced VH is not clearly known. To assess the effects of EA on ileitis-induced VH and confirm whether EA attenuates VH through spinal PAR-2 activation and CGRP release, goats received an injection of 2,4,6-trinitro-benzenesulfonic-acid (TNBS) solution into the ileal wall. TNBS-injected goats were allocated into VH, Sham acupuncture (Sham-A) and EA groups, while goats treated with saline instead of TNBS solution were used as the control. Goats in EA group received EA at bilateral Hou-San-Li acupoints for 0.5 h at 7 days and thereafter repeated every 3 days for 6 times. Goats in the Sham-A group were inserted with needles for 0.5 h at the aforementioned acupoints without any hand manipulation and electric stimulation. Visceromotor responses to colorectal distension, an indicator of VH, were recorded by electromyography. The terminal ileum and thoracic spinal cord (T11) were sampled for evaluating ileitis at days 7 and 22, and distribution and expression-levels of PAR-2, CGRP and c-Fos on day 22. TNBS-treated-goats exhibited apparent transmural-ileitis on day 7, microscopically low-grade ileitis on day 22 and VH at days 7-22. Goats of Sham-A, VH or EA group showed higher (P < 0.01) VH at days 7-22 than the Control-goats. EA-treated goats exhibited lower (P < 0.01) VH as compared with Sham-A or VH group. Immunoreactive-cells and expression-levels of spinal PAR-2, CGRP and c-Fos in the EA group were greater (P < 0.01) than those in the Control group, but less (P < 0.01) than those in Sham-A and VH groups on day 22. Downregulation of spinal PAR-2 and CGRP levels by EA attenuates the ileitis and resultant VH.

Repairing and Analgesic Effects of Umbilical Cord Mesenchymal Stem Cell Transplantation in Mice with Spinal Cord Injury.

Transplantation of human umbilical cord mesenchymal stem cells (hUC-MSCs) into spinal cord injury (SCI) may alleviate neuropathic pain and promote functional recovery. The underlying mechanism likely involves activation of glial cells and regulation of inflammatory factors but requires further validation. SCI was induced in 16 ICR mice using an SCI compression model, followed by injection of lentiviral vector-mediated green fluorescent protein- (GFP-) labeled hUC-MSCs 1 week later. Behavioral tests, histological evaluation, and inflammatory factor detection were performed in the treatment (SCI+hUC-MSCs) and model (SCI) groups. Histological evaluation revealed GFP expression in the spinal cord tissue of the treatment group, implying that the injected MSCs successfully migrated to the SCI. The Basso, Beattie, and Bresnahan (BBB) scores showed that motor function gradually recovered over time in both groups, but recovery speed was significantly higher in the treatment group than in the model group. The pain threshold in mice decreased after SCI but gradually increased over time owing to the self-repair function of the body. The corresponding pain threshold of the treatment group was significantly higher than that of the model group, indicating the therapeutic and analgesic effects of hUC-MSCs. Expression of IL-6 and TNF-α in the spinal cord tissue of the treated group decreased, whereas glial cell line-derived neurotrophic factor (GDNF) expression along with ED1 expression increased compared with those in the model group, suggesting that SCI activated ED1 inflammatory macrophages/microglia, which were subsequently reduced by hUC-MSC transplantation. hUC-MSCs are speculated to enhance the repair of the injured spinal cord tissue and exert an analgesic effect by reducing the secretion of inflammatory factors IL-6 and TNF-α and upregulating the expression of GDNF.

Effects of chronic unpredictable mild stress on ovarian reserve in female rats: Feasibility analysis of a rat model of premature ovarian failure.

Premature ovarian failure (POF) results from a number of disorders. The POF model is primarily based on chemotherapeutic injury, and hence is not suitable for assessing the effects of chronic stress on ovarian function. Therefore, improved animal models are required to analyze the effects of chronic stress on ovarian reserve. The feasibility of the chronic unpredictable mild stress (CUMS) method for establishing a model of POF was examined. The depressive behavior exhibited by rats was evaluated with the open field and sucrose preference tests. Vaginal smears were obtained for assessment of the estrous cycle. The ovarian reserve of the animals was evaluated using the estrous cycle, ovarian histology and serum levels of gonadotropin releasing hormone (GnRH), follicle­stimulating hormone (FSH), estradiol (E2), and anti­Müllerian hormone (AMH). Compared with the control group, body weight, time spent in the center, horizontal movement, vertical frequency, consumption of sucrose, sucrose preference, number of small follicles from the rats, and serum E2, AMH and GnRH levels were significantly decreased in the CUMS group (all P<0.05). However, the estrous cycle was prolonged significantly (P<0.05) and serum FSH levels were increased significantly (P<0.01). These results suggested that the CUMS model rats exhibited depression­like behaviors. CUMS may induce psychological stress and decrease ovarian reserve in female rats. Thus, the CUMS model may be used to assess the effects of chronic stress on female reproductive function.

Analgesic and physiological effect of electroacupuncture combined with epidural lidocaine in goats.

OBJECTIVE: To investigate physiological and antinociceptive effects of electroacupuncture (EA) with lidocaine epidural nerve block in goats. STUDY DESIGN: Prospective experimental trial. ANIMALS: Forty-eight hybrid male goats weighing 27 ± 2 kg. METHODS: The goats were randomly assigned to six groups: L2.2, epidural lidocaine (2.2 mg kg-1); L4.4, epidural lidocaine (4.4 mg kg-1); EA; EA-L1.1, EA with epidural lidocaine (1.1 mg kg-1); EA-L2.2, EA with epidural lidocaine (2.2 mg kg-1); and EA-L4.4, EA with epidural lidocaine (4.4 mg kg-1). EA was administered for 120 minutes. Epidural lidocaine was administered 25 minutes after EA started. Nociceptive thresholds of flank and thigh regions, abdominal muscle tone, mean arterial pressure (MAP), heart rate (HR), respiratory frequency (fR) and rectal temperature were recorded at 30, 60, 90, 120, 150 and 180 minutes. RESULTS: Lidocaine dose-dependently increased nociceptive thresholds. There were no differences in nociceptive thresholds between L4.4 and EA from 30 to 120 minutes. The threshold in EA-L2.2 was lower than in EA-L4.4 from 30 to 120 minutes, but higher than in EA-L1.1 from 30 to 150 minutes or in L4.4 from 30 to 180 minutes. The abdominal muscle tone in EA-L2.2 was higher at 30 minutes, but lower at 90 and 120 minutes than at 0 minutes. There were no differences in muscle tone between L4.4 and L2.2 or EA-L4.4, and between any two of the three EA-lidocaine groups from 0 to 180 minutes. The fR and HR decreased in L4.4 at 60 and 90 minutes compared with 0 minutes. No differences in fR, HR, MAP and temperature among the groups occurred from 30 to 180 minutes. CONCLUSIONS AND CLINICAL RELEVANCE: EA combined with 2.2 mg kg-1 epidural lidocaine provides better antinociceptive effect than 4.4 mg kg-1 epidural lidocaine alone in goats. EA provided antinociception and allowed a decrease in epidural lidocaine dose.

Monitoring menstrual cycle, gestation and lactation by measuring urinary oestradiol and progesterone in the captive golden snub-nosed monkey (Rhinopithecus roxellanae).

The golden snub-nosed monkey is an endangered species and study of its reproductive physiology is crucial for the species' breeding programs. Urine samples (770) from 5 mature female golden snub-nosed monkeys were collected in the Shengnongjia Nature Reserve between October 2013 and December 2014 to monitor their menstrual cycle, gestation, and lactation. The concentrations of oestradiol (E2) and progesterone (P4) in the samples were measured by Chemiluminescent Microparticle Immunoassay (CMIA), and the hormone concentrations were indexed to creatinine levels to compensate for differences in water content. The results showed that the E2 and P4 levels during the breeding season were significantly higher than those during the non-breeding season (P<0.01). The length of the menstrual cycle during the breeding season was 24.29±0.71days (mean±SEM) with a follicular cycle of 8.33±0.62days and luteal cycle of 15.27±0.83days. In addition, the levels of E2 and P4 began to rise on day 14 and day 10 after conception and remained at a high level until parturition. However, the E2 and P4 levels during lactation were lower than those during gestation (P<0.01). In summary, this study extends our knowledge regarding the basic reproductive physiology of golden snub-nosed monkeys, which could play an important role in the expansion of this species' population.

Exploring the Mechanisms of Electroacupuncture-Induced Analgesia through RNA Sequencing of the Periaqueductal Gray.

Electroacupuncture (EA) can relieve various pains. However, its mechanism in terms of the transcriptome is still not well-known. To explore the full profile of EA-induced molecular modification in the central nerve system, three twins of goats were selected for a match-paired experiment: EA stimulation (60 Hz, 30 min) and none-EA (control). Goats in the EA group showed an increased (p < 0.05) nociceptive threshold compared with the control goats. Experimental goats were sacrificed at 4 h of the experiment, and the periaqueductal grays were harvested for RNA sequencing. As a result, 2651 differentially expressed genes (1803 up-regulated and 848 down-regulated genes) were found and enriched in 30 Kyoto Encyclopedia of Genes and Genomes pathways and 149 gene ontology terms. EA-regulated five neuropeptide genes (proenkephalin, proopiomelanocortin, preprodynorphin, diazepam-binding inhibitor and proprotein convertase 1 inhibitor) were validated with quantitative PCR. Furthermore, up-regulated glutamate receptors, glutamate transporters, γ-aminobutyric acid (GABA) receptors, GABA transporters, synaptotagmins or mitogen-activated protein kinase (MAPK) genes might contribute to EA-induced analgesia through regulating the glutamatergic synapse, GABAergic synapse, MAPKs, ribosome or ubiquitin-proteasome pathways. Our findings reveal a full profile of molecular modification in response to EA and provide a solid experimental framework for exploring the mechanisms underlying EA-induced analgesia.

Electroacupuncture Inhibits the Activation of p38MAPK in the Central Descending Facilitatory Pathway in Rats with Inflammatory Pain.

The mitogen-activated protein kinases (MAPKs), especially p38MAPK, play a pivotal role in chronic pain. Electroacupuncture (EA) relieves inflammatory pain underlying the descending pathway, that is, the periaqueductal gray (PAG), the rostral ventromedial medulla (RVM), and the spinal cord dorsal horn (SCDH). However, whether EA antagonizes inflammatory pain through regulation of p38MAPK in this descending facilitatory pathway is unclear. Complete Freund's adjuvant (CFA) was injected into the hind paw of rats to establish inflammatory pain model. EA was administrated for 30 min at Zusanli and Kunlun acupoints at 0.5, 24.5, 48.5, and 72.5 h, respectively. The paw withdrawal threshold (PWT), paw edema, and Phosphor-p38MAPK-Immunoreactivity (p-p38MAPK-IR) cells were measured before (0 h) and at 1, 3, 5, 7, 25, and 73 h after CFA or saline injection. EA increased PWT at 1, 3, 25, and 73 h and inhibited paw edema at 25 and 73 h after CFA injection. Moreover, the increasing number of p-p38MAPK-IR cells which was induced by CFA was suppressed by EA stimulation in PAG and RVM at 3 and 5 h and in SCDH at 5, 7, 25, and 73 h. These results suggest that EA suppresses inflammation-induced hyperalgesia probably through inhibiting p38MAPK activation in the descending facilitatory pathway.

Visceral pain triggered by traction on the ileocecal ligament with ileitis.

BACKGROUND: Visceral pain is a common symptom of several gastrointestinal disorders. Despite tremendous progress in understanding its basic mechanisms, it remains a significant health challenge for clinicians. The present study quantified the intensity of visceral pain using ileocecal ligament traction on an inflamed ileum in goats. MATERIALS AND METHODS: A total of 36 male goats weighing 20.05±2.1 kg were randomly allocated equally into a 2,4,6-trinitrobenzenesulfonic acid (TNBS) group (n=18) and a saline group (n=18). Ileitis was induced via the injection of 30 mg TNBS dissolved in 30% ethanol into the ileal wall through a laparotomy. An equal volume of normal saline was injected into the ileal wall of the saline goats. Behavioral responses to traction (2, 4, and 6 N) on the ileocecal ligament were observed on days 3, 7, and 14. Six goats from each group received a laparotomy and partial intestinal resection for ileal sample collection immediately after behavioral testing on days 3, 7, and 14. Ileal histopathological changes were assessed and concentrations of myeloperoxidase, IL-1ß, IL-6, and TNFα investigated using enzyme-linked immunosorbent assay. RESULTS: The TNBS-treated goats exhibited remarkably increased macroscopic scores, mast-cell counts, myeloperoxidase, and TNFα concentrations on days 3 and 7 compared to the saline group, and increased microscopic scores and IL-1ß and IL-6 concentrations on days 3-14. The TNBS-treated goats exhibited behavioral changes in response to traction in the same pattern as their microscopic changes and cytokine levels. The traction force correlated positively with pain-behavior responses. CONCLUSION: Traction on the ileocecal ligament of goats with ileitis provoked an apparent, stable, and reproducible ileum-derived pain. The current model may be helpful in evaluating the efficacy of new drugs for the management of visceral pain and in investigating its underlying mechanisms.

A novel model for studying ileitis-induced visceral hypersensitivity in goats.

BACKGROUND: Visceral hypersensitivity (VH) is a common condition in many gastrointestinal disorders such as inflammatory bowel diseases (IBDs) in human and animals. Most studies often induce Crohn's disease/colitis to investigate VH in small experimental animals. Although farm animals commonly suffer from IBDs, their VH has not been investigated so far. Because goats can suffer from Johne's disease, a naturally occurring Crohn's-like disease, they may be suitable to be used for studying the mechanism underlying VH in common intestinal disorders of large animals. In the present study, 60 healthy goats of either sex were equally divided into a 2, 4, 6-trinitrobenzenesulfonic acid (TNBS) group and saline group. A volume of 1.2 ml of TNBS-ethanol solution (30 mg TNBS in 40 % ethanol) or an equal volume of isotonic saline was injected into the wall of the terminal ileum through laparotomy. The severity of the developing ileitis was determined according to macro- and microscopic pathologic scores and the levels of myeloperoxidase, interleukin-1ß, interleukin-6 and tumor necrosis factor-α, and VH was evaluated with visceromotor responses (VMR) to colorectal distension on days 3, 7, 14, 21 and 28. VMRs were assessed with a continuous ramp distention mode with 6 s for each pressure (20, 40, 60, 80 and 100 mmHg). RESULTS: Compared to the saline group, the TNBS-treated goats showed apparent transmural pathological changes and a significant increase (P < 0.05) in macroscopic and microscopic change scores, and levels of myeloperoxidase, interleukin-1ß, interleukin-6 and tumor necrosis factor-α in the ileum, and VMR to colorectal distension. The goats exhibited apparent ileitis at days 3 to 21, and VH at days 7 to 28 following TNBS treatment. CONCLUSION: This experiment successfully established a reproducible ileitis and VH with administration of TNBS-ethanol solution in the ileal wall of goats. This model is useful for studying the pathogenesis of the IBD and the mechanism underlying VH, and for evaluating the efficacy of new therapeutic regimens.

Visceral Hypersensitivity Is Provoked by 2,4,6-Trinitrobenzene Sulfonic Acid-Induced Ileitis in Rats.

BACKGROUND AND AIMS: Crohn's Disease (CD), a chronic Inflammatory Bowel Disease, can occur in any part of the gastrointestinal tract, but most frequently in the ileum. Visceral hypersensitivity contributes for development of chronic abdominal pain in this disease. Currently, the understanding of the mechanism underlying hypersensitivity of Crohn's ileitis has been hindered by a lack of specific animal model. The present study is undertaken to investigate the visceral hypersensitivity provoked by 2,4,6-trinitrobenzene sulfonic (TNBS)-induced ileitis rats. METHODS: Male Sprague-Dawley rats were anaesthetized and laparotomized for intraileal injection of TNBS (0.6 ml, 80 mg/kg body weight in 30% ethanol, n = 48), an equal volume of 30% Ethanol (n = 24), and Saline (n = 24), respectively. Visceral hypersensitivity was assessed by visceromotor responses (VMR) to 20, 40, 60, 80, and 100 mmHg colorectal distension pressure (CRD) at day 1, 3, 7, 14, 21, and 28. Immediately after CRD test, the rats were euthanized for collecting the terminal ileal segment for histopathological examinations and ELISA of myleoperoxidase and cytokines (TNF-α, IL-1ß, IL-6), and dorsal root ganglia (T11) for determination of calcitonin gene-related peptide by immunohistochemistry, respectively. RESULTS: Among all groups, TNBS-treatment showed transmural inflammation initially at 3 days, reached maximum at 7 days and persisted up to 21 days. The rats with ileitis exhibited (P < 0.05) VMR to CRD at day 7 to day 21. The calcitonin gene-related peptide-immunoreactive positive cells increased (P < 0.05) in dorsal root ganglia at day 7 to 21, which was persistently consistent with visceral hypersensitivity in TNBS-treated rats. CONCLUSION: TNBS injection into the ileum induced transmural ileitis including granuloma and visceral hypersensitivity. As this model mimics clinical manifestations of CD, it may provide a road map to probe the pathogenesis of gut inflammation and visceral hypersensitivity, as well as for establishing the therapeutic protocol for Crohn's ileitis.

Analgesic Neural Circuits Are Activated by Electroacupuncture at Two Sets of Acupoints.

To investigate analgesic neural circuits activated by electroacupuncture (EA) at different sets of acupoints in the brain, goats were stimulated by EA at set of Baihui-Santai acupoints or set of Housanli acupoints for 30 min. The pain threshold was measured using the potassium iontophoresis method. The levels of c-Fos were determined with Streptavidin-Biotin Complex immunohistochemistry. The results showed pain threshold induced by EA at set of Baihui-Santai acupoints was 44.74% ± 4.56% higher than that by EA at set of Housanli acupoints (32.64% ± 5.04%). Compared with blank control, EA at two sets of acupoints increased c-Fos expression in the medial septal nucleus (MSN), the arcuate nucleus (ARC), the nucleus amygdala basalis (AB), the lateral habenula nucleus (HL), the ventrolateral periaqueductal grey (vlPAG), the locus coeruleus (LC), the nucleus raphe magnus (NRM), the pituitary gland, and spinal cord dorsal horn (SDH). Compared with EA at set of Housanli points, EA at set of Baihui-Santai points induced increased c-Fos expression in AB but decrease in MSN, the paraventricular nucleus of the hypothalamus, HL, and SDH. It suggests that ARC-PAG-NRM/LC-SDH and the hypothalamus-pituitary may be the common activated neural pathways taking part in EA-induced analgesia at the two sets of acupoints.

Electroacupuncture relieves neuropathic pain via upregulation of glutamate transporters in the spinal cord of rats.

Glutamate transports (GTs), the only vehicle for removal of glutamate from the extracellular fluid, is reported to be related to chronic pain. To investigate whether the glutamate/aspartate transporter (GLAST) and glutamate transporter-1 (GLT-1) participate in electroacupuncture (EA) analgesia, the EA effect was observed with paw withdraw threshold in a rat model of spared nerve injury. The expression levels of GLAST and GLT-1 were determined with Western Blot and RT-PCR. The results showed significantly upregulated GLAST and GLT-1, along with the relieved pain behaviors after EA treatment. In addition, intrathecal injection of GTs inhibitor, l-trans-pyrrolidine-2-4-dicarboxylate, attenuated the EA-induced analgesic effect. The experiment demonstrates that EA can increase the GTs of neuropathic pain rats, which might be one of the mechanisms underlying its effectiveness in the neuropathic pain.

[Progress of Researches on Central Mechanism of Electroacupuncture Tolerance].

Electroacupuncture (EA) has been demonstrated effective for pain relief. However, repeated application may decline analgesic effect of EA, which is termed EA tolerance, that reduces the clinical efficacy of EA. Therefore, it has attracted attention from researchers in recent years and the progresses include:(1) acute and chronic EA tolerance animal models have been established; (2) cross-tolerance between EA and morphine; (3) Anti-opioid substances, including cholecystokinin, orphanin FQ and angiotensin Ⅱ, have been reported to contribute to EA tolerance; (4) glutamate receptors and transporters, 5-hydroxytryptamine and norepinephrine have been revealed involvement in EA tolerance; (5) cyclic adenosine monophosphate, cyclic guanosine monophosphate and Ca2+ have been reported to be the second messengers cellularly in EA tolerance. The current EA tolerance effect lacks in-depth researches. Therefore, studies on its molecular mechanisms and signaling pathway are necessarily required.

Overexpression of brain-derived neurotrophic factor in the hippocampus protects against post-stroke depression.

Post-stroke depression is associated with reduced expression of brain-derived neurotrophic factor (BDNF). In this study, we evaluated whether BDNF overexpression affects depression-like behavior in a rat model of post-stroke depression. The middle cerebral artery was occluded to produce a model of focal cerebral ischemia. These rats were then subjected to isolation-housing combined with chronic unpredictable mild stress to generate a model of post-stroke depression. A BDNF gene lentiviral vector was injected into the hippocampus. At 7 days after injection, western blot assay and real-time quantitative PCR revealed that BDNF expression in the hippocampus was increased in depressive rats injected with BDNF lentivirus compared with depressive rats injected with control vector. Furthermore, sucrose solution consumption was higher, and horizontal and vertical movement scores were increased in the open field test in these rats as well. These findings suggest that BDNF overexpression in the hippocampus of post-stroke depressive rats alleviates depression-like behaviors.

The Expression Patterns of c-Fos and c-Jun Induced by Different Frequencies of Electroacupuncture in the Brain.

To investigate patterns of c-Fos and c-Jun expression induced by different frequencies of electroacupuncture (EA) in the brain, goats were stimulated by EA of 0, 2, 60, or 100 Hz at a set of "Baihui, Santai, Ergen, and Sanyangluo" points for 30 min. The pain threshold was measured using the potassium iontophoresis method. The levels of c-Fos and c-Jun were determined with Streptavidin-Biotin Complex immunohistochemistry. The results showed that the pain threshold induced by 60 Hz was 82.2% higher (P < 0.01) than that by 0, 2, or 100 Hz (6.5%, 35.2%, or 40.9%). EA induced increased c-Fos and c-Jun expression in most analgesia-related nuclei and areas in the brain. Sixty Hz EA increased more c-Fos or c-Jun expression than 2 Hz or 100 Hz EA in all the measured nuclei and areas except for the nucleus accumbens, the area septalis lateralis, the caudate nucleus, the nucleus amygdala basalis, and the locus coeruleus, in which c-Fos or c-Jun expressions induced by 60 Hz EA did not differ from those by 2 Hz or 100 Hz EA. It was suggested that 60 Hz EA activated more extensive neural circuits in goats, which may contribute to optimal analgesic effects.

TNF/TNFR1 pathway and endoplasmic reticulum stress are involved in ofloxacin-induced apoptosis of juvenile canine chondrocytes.

BACKGROUND AND PURPOSE: Quinolones cause obvious cartilaginous lesions in juvenile animals by chondrocyte apoptosis, which results in the restriction of their use in pediatric and adolescent patients. Studies showed that chondrocytes can be induced to produce TNFα, and the cisternae of the endoplasmic reticulum in quinolone-treated chondrocytes become dilated. We investigated whether TNF/TNFR1 pathway and endoplasmic reticulum stress (ERs) are involved in ofloxacin (a typical quinolone)-induced apoptosis of juvenile canine chondrocytes. EXPERIMENTAL APPROACH: Canine juvenile chondrocytes were treated with ofloxacin. Cell survival and apoptosis rates were determined with MTT method and flow cytometry, respectively. The gene expression levels of the related signaling molecules (TNFα, TNFR1, TRADD, FADD and caspase-8) in death receptor pathways and main apoptosis-related molecules (calpain, caspase-12, GADD153 and GRP78) in ERs were measured by qRT-PCR. The gene expression of TNFR1 was suppressed with its siRNA. The protein levels of TNFα, TNFR1 and caspase-12 were assayed using Western blotting. KEY RESULTS: The survival rates decreased while apoptosis rates increased after the chondrocytes were treated with ofloxacin. The mRNA levels of the measured apoptosis-related molecules in death receptor pathways and ERs, and the protein levels of TNFα, TNFR1 and caspase-12 increased after the chondrocytes were exposed to ofloxacin. The downregulated mRNA expressions of TNFR1, Caspase-8 and TRADD, and the decreased apoptosis rates of the ofloxacin-treated chondrocytes occurred after TNFR1-siRNA interference. CONCLUSIONS AND IMPLICATIONS: Ofloxacin-induced chondrocyte apoptosis in a time- and concentration-dependent fashion. TNF/TNFR1 pathway and ERs are involved in ofloxacin-induced apoptosis of juvenile canine chondrocytes in the early stage.

Electroacupuncture-induced dynamic processes of gene expression levels of endogenous opioid Peptide precursors and opioid receptors in the CNS of goats.

In order to investigate the dynamic processes of mRNA levels of proenkephalin, proopiomelanocortin, prodynorphin, and opioid receptors (δ-, µ-, and κ-receptor) induced by electroacupuncture (EA) in the central nerve system, goats were stimulated by EA of 60 Hz for 0.5 h at a set of Baihui, Santai, Ergen, and Sanyangluo points. The pain threshold was measured using the method of potassium iontophoresis. The mRNA levels of the three opioid peptide precursors and three opioid receptors were determined with quantitative real-time PCR and the levels of Met-enkephalin with SABC immunohistochemistry at 0.5 h before and at 0, 2, 4, 6, 8, 12, and 24 h after EA. The results showed that the pain threshold correlated (P < 0.01) with Met-enkephalin immunoactivities in the measured nuclei and areas of goats. The analgesic aftereffect lasted for 12 h at least. The mRNA levels of the three opioid peptide precursors and three opioid receptors began to increase at 0 h, reached the peak during the time from 4 h to 6 h or at 12 h, and remained higher at 24 h after EA was discontinued. These results suggested that the initiation of gene expression of opioid peptides and the three receptors may be associated with EA-induced analgesic aftereffect.

Effects of electroacupuncture of different frequencies on the release profile of endogenous opioid peptides in the central nerve system of goats.

To investigate the release profile of met-enkephalin, ß-endorphin, and dynorphin-A in ruminants' CNS, goats were stimulated by electroacupuncture of 0, 2, 40, 60, 80, or 100 Hz for 30 min. The pain threshold was measured using potassium iontophoresis. The peptide levels were determined with SABC immunohistochemisty. The results showed that 60 Hz increased pain threshold by 91%; its increasing rate was higher (P < 0.01) than any other frequency did. 2 Hz and 100 Hz increased met-enkephalin immunoactivities (P < 0.05) in nucleus accumbens, septal area, caudate nucleus, amygdala, paraventricular nucleus of hypothalamus, periaqueductal gray, dorsal raphe nucleus, and locus ceruleus. The two frequencies elicited ß-endorphin release (P < 0.05) in nucleus accumbens, septal area, supraoptic nucleus, ventromedial nucleus of hypothalamus, periaqueductal gray, dorsal raphe nucleus, locus ceruleus, solitary nucleus and amygdala. 60 Hz increased (P < 0.05) met-enkephalin or ß-endorphin immunoactivities in the nuclei and areas mentioned above, and habenular nucleus, substantia nigra, parabrachial nucleus, and nucleus raphe magnus. High frequencies increased dynorphin-A release (P < 0.05) in spinal cord dorsal horn and most analgesia-related nuclei. It suggested that 60 Hz induced the simultaneous release of the three peptides in extensive analgesia-related nuclei and areas of the CNS, which may be contributive to optimal analgesic effects and species variation.

Physiologic effects of electroacupuncture combined with intramuscular administration of xylazine to provide analgesia in goats.

OBJECTIVE: To investigate physiologic effects of electroacupuncture (EA) combined with xylazine administration in goats. ANIMALS: 48 healthy crossbred goats. PROCEDURES: Goats were randomly allotted to 8 groups of 3 (nonpregnant and nonlactating) female goats and 3 male goats each. The 8 treatment groups were as follows: 1 EA group, 3 xylazine (0.1, 0.2, and 0.4 mg/kg, IM) groups, 3 EA plus xylazine (0.1, 0.2, and 0.4 mg/kg, IM) groups, and 1 control group. Electroacupuncture was performed for 90 minutes. Xylazine was administered 20 minutes after EA was performed. Pain threshold, heart rate, mean arterial pressure (MAP), respiration rate, and rectal temperature were observed at 0, 5, 25, 45, 65, and 85 minutes after xylazine administration. RESULTS: Xylazine administered at 0.4 mg/kg increased the pain threshold and reduced MAP. Xylazine administered at 0.1, 0.2, or 0.4 mg/kg reduced heart rate, respiration rate, and temperature. Electroacupuncture increased the pain threshold but had no effect on heart rate, MAP, respiratory rate, or rectal temperature. Pain threshold in goats that underwent EA plus xylazine administration was higher than in goats that received EA or xylazine alone. Electroacupuncture combined with xylazine at 0.1 mg/kg did not affect heart rate, MAP, respiratory rate, or rectal temperature. Pain threshold in goats that underwent EA plus xylazine administration at 0.1 mg/kg was higher than in goats given xylazine at 0.4 mg/kg alone. CONCLUSIONS AND CLINICAL RELEVANCE: Electroacupuncture combined with xylazine, even at 0.1 mg/kg, provided analgesia without significantly affecting cardiorespiratory parameters or rectal temperature in goats.

[Effect of Ca2+ complexation on oxygen partial pressure in the Bladder Meridian in goats].

OBJECTIVE: To explore the relationship between energy metabolism and meridian phenomenon. Methods Ten Boer hybridism goats mitigated under chlorpromazine (0.85 mg/kg, intramuscular injection) were subjected to the present study. Changes of oxygen partial pressure (PO2) in "Ganshu" (BL 18), "Dachangshu" (BL 25) and "Guanyuanshu" (BL 26) of Bladder Meridian and in 3 non-acupoints (3 cm apart from BL18, BL25 and BL26 separately on the unilateral side) were recorded by using a needle-type tissue oxygen tension sensor before and following local injection of EDTA-Na2 (200 microL, 0.05 kg/mol, for complexing Ca2+) and 0.9% saline. RESULTS: (1) Compared with the corresponding non-acupoints, Ca2+ potentials in BL18, BL25 and BL26 were all significantly higher (P < 0.05, 0.01). (2) In comparison with the corresponding non-acupoints, the values of tissue PO2 of BL18 and BL26 were significantly higher (P < 0.01). (3) After injection of EDTA-Na2, PO2 values in both BL18, BL26, and their respective non-acupoints increased significantly in comparison with those of either injection of saline or their respective basal values (P < 0.01, 0.05). Compared with those of their corresponding non-acupoints PO2 values in both BL18 and BL26 increased markedly (P < 0.01). CONCLUSION: Ca2+ potential of the Bladder Meridian was significantly higher than that of non-acupoints, and after complexing Ca2+, PO2 in acupoints and non-acupoints increased markedly, suggesting that Ca2+ may play an important role in meridian signaling and production of acupuncture effect.