关节炎大鼠脊髓背角降钙素基因相关肽和P物质的变化及针刺效应

将行为学实验与免疫组化ＬＳＡＢ技术结合，观察了大鼠在佐剂性关节炎发生发展中及针刺治疗时，脊髓背角降钙素基因相关肽（ＣＧＲＰ）和Ｐ物质（ＳＰ）的动态变化。结果表明，正常大鼠ＣＧＲＰ主要分布于脊髓背角Ⅰ、Ⅱ、Ⅴ、Ⅹ层和利骚厄氏束，ＳＰ主要分布于脊髓背角浅层。注入佐剂后第２天形成急性关节炎时，背角浅层和灰质后联合中ＣＧＲＰ免疫活性物质（ＣＧＲＰ－ＬＩ）和ＳＰ免疫活性物质（ＳＰ－ＬＩ）有所增加；第１４天发展为多发性关节炎时进一步明显增加，而且在灰质后联合中可见ＣＧＲＰ－ＬＩ长纤维；第２８天后随佐剂性关节炎的逐渐恢复而恢复。电针双侧环跳穴可减轻佐剂性关节炎大鼠的自发痛和痛觉过敏，并可预防多发性关节炎的发生，同时可见ＣＧＲＰ－ＬＩ和ＳＰ－ＬＩ增加的反应减弱。结果提示，佐剂性关节炎大鼠脊髓背角ＣＧＲＰ和ＳＰ的变化与关节炎的发生发展密切相关     

Effect of local anaesthesia and/or analgesia on pain responses induced by piglet castration

Background

Surgical castration in male piglets is painful and methods that reduce this pain are requested. This study evaluated the effect of local anaesthesia and analgesia on vocal, physiological and behavioural responses during and after castration. A second purpose was to evaluate if herdsmen can effectively administer anaesthesia.

Methods

Four male piglets in each of 141 litters in five herds were randomly assigned to one of four treatments: castration without local anaesthesia or analgesia (C, controls), analgesia (M, meloxicam), local anaesthesia (L, lidocaine), or both local anaesthesia and analgesia (LM). Lidocaine (L, LM) was injected at least three minutes before castration and meloxicam (M, LM) was injected after castration. During castration, vocalisation was measured and resistance movements judged. Behaviour observations were carried out on the castration day and the following day. The day after castration, castration wounds were ranked, ear and skin temperature was measured, and blood samples were collected for analysis of acute phase protein Serum Amyloid A concentration (SAA). Piglets were weighed on the castration day and at three weeks of age. Sickness treatments and mortality were recorded until three weeks of age.

Results

Piglets castrated with lidocaine produced calls with lower intensity (p < 0.001) and less resistance movements (p < 0.001) during castration. Piglets that were given meloxicam displayed less pain-related behaviour (huddled up, spasms, rump-scratching, stiffness and prostrated) on both the castration day (p = 0.06, n.s.) and the following day (p = 0.02). Controls had less swollen wounds compared to piglets assigned to treatments M, L and LM (p < 0.001). The proportion of piglets with high SAA concentration (over threshold values 200, 400 mg/l) was higher (p = 0.005; p = 0.05) for C + L compared to M + LM. Ear temperature was higher (p < 0.01) for controls compared to L and LM. There were no significant treatment effects for skin temperature, weight gain, sickness treatments or mortality.

Conclusions

The study concludes that lidocaine reduced pain during castration and that meloxicam reduced pain after castration. The study also concludes that the herdsmen were able to administer local anaesthesia effectively.     

P物质与犬术后急性疼痛强度关系

P物质与术后疼痛密切相关,为了探究P物质与犬术后急性疼痛强度的关系,本试验基于比格犬术后急性疼痛模型,通过量表评分和P物质基因表达量比较研究犬术后急性疼痛强度。结果显示,试验组犬术后疼痛在1～24h期间明显高于假手术组(P0.05),P物质基因表达量与量表评分对应良好,呈正相关。结果表明,P物质的基因表达量跟疼痛强度呈正相关,为犬术后疼痛的量化和科学干预奠定基础,对推进动物疼痛最小化有重要意义。     

Effect of yohimbine hydrochloride on serum prolactin concentration in the rat: possible antagonist for fescue toxicosis

Yohimbine hydrochloride is an indole alkaloid which blocks alpha 2-adrenergic and dopamine receptors and stimulates serotonergic receptors. Yohimbine was selected for testing as a possible antagonist in fescue toxicosis. Reduced body weight gains in cattle with chronic fescue toxicosis may be due to ergot alkaloids produced by fungi which infect the fescue grass. Ergot alkaloids stimulate dopamine receptors, antagonize serotonin, and lower serum prolactin concentrations. It was hypothesized that yohimbine may reverse or counteract the effects of the toxic fescue. Investigation was made of the treatment effects of multiple doses of yohimbine given in rats by intraperitoneal and oral routes. Given intraperitoneally once a day for 8 days, yohimbine hydrochloride increased serum prolactin concentrations. When given orally in feed for 7 days, the drug decreased the serum prolactin concentration. The effects of yohimbine on prolactin concentrations were dependent on the dosages and routes of administration. The inability of yohimbine, when given orally, to increase serum prolactin levels decreased its potential usefulness for prolonged treatment of fescue toxicosis.     

Intra‐articular opioid analgesia is effective in reducing pain and inflammation in an equine LPS induced synovitis model

Reasons for performing study: Intra‐articular administration of morphine as a local analgesic and anti‐inflammatory drug is widely used in human medicine. In equids, little is known about its clinical analgesic and anti‐inflammatory efficacy. Objectives: To use an inflammatory orthopaedic pain model to investigate the analgesic and anti‐inflammatory effects of intra‐articularly administered morphine as a new treatment modality in horses with acute arthritis. Methods: In a crossover study design, synovitis was induced in the left or right talocrural joint by means of intra‐articular injection of 0.5 ng lipopolyssacharide (LPS). The effect of 120 mg morphine, intra‐articularly administered at 1 h after induction of synovitis, was evaluated using both physiological and behavioural pain variables. Synovial fluid was sampled at 0, 4, 8, 28 and 52 h after induction of synovitis and analysed for total protein concentration, leucocyte count and for prostaglandin E₂, bradykinin and substance P concentrations by ELISA. Ranges of motion of metatarsophalangeal and talocrural joints were measured as kinematic variables with the horses walking and trotting on a treadmill under sound and lame conditions. Clinical lameness scores and several behavioural variables related to the perception of pain were obtained. Results: LPS injection caused marked transient synovitis, resulting in increased concentrations of inflammatory synovial fluid markers, clinical lameness, joint effusion and several behavioural changes, such as increased time spent recumbent, decreased limb loading at rest and decreased time spent eating silage. Intra‐articular morphine resulted in a significant decrease in synovial white blood cell count, prostaglandin E₂ and bradykinin levels and improvement in clinical lameness, kinematic and behavioural parameters, compared to placebo treatment. Conclusions: Intra‐articular morphine offers potent analgesic and anti‐inflammatory effects in horses suffering from acute synovitis. Potential relevance: Local administration of opioids may be useful for horses with acute inflammatory joint pain and offers possibilities for multimodal analgesic therapies without opioid‐related systemic side effects.     

Evaluation of a stress model induced by dietary corticosterone supplementation in broiler breeders: effects on egg yolk corticosterone concentration and biochemical blood parameters

1. This study aimed to evaluate a stress model induced by corticosterone (CORT) supplementation in the diet of broiler breeder hens.

2. A total of 60 Ross broiler breeder hens at 29 weeks of age were randomly divided into 4 groups with 15 hens each. The first group served as the control. The rest of the hens were given 1, 1.5 or 2 mg of CORT/hen/d (CORT₁, CORT_1.5 and CORT₂, respectively) for 7 d. Concentrations of yolk CORT, plasma uric acid, glucose, cholesterol, creatine kinase, heterophil (H):lymphocyte (L) ratio and duration of tonic immobility (TI) were measured at d 3, 5 and 7 of CORT supplementation. The same measurements were repeated at 3, 5 and 7 d after CORT was withdrawn from the diet.

3. There were no significant CORT dose effect on yolk CORT and plasma glucose concentrations. Higher plasma uric acid and H:L ratio was obtained for CORT_1.5 and CORT₂ than for CORT₁. From 3 to 7 d of dietary CORT supplementation, yolk CORT and plasma uric acid concentrations and H:L ratio increased whereas plasma glucose concentration decreased. After CORT was withdrawn from the diet, the H:L ratio remained elevated. The duration of TI and plasma creatine kinase concentration did not change during and after CORT supplementation.

4. Yolk CORT concentration was correlated with plasma uric acid concentration during CORT supplementation.

5. The results suggest that dietary CORT supplementation could be used as a stress model and to evaluate hormone-mediated maternal effects in broiler breeder hens.     

Effects of substance P on fluid and amylase secretion in exocrine pancreas of rat and mouse

The effects of substance P on fluid and amylase secretion were examined in the exocrine pancreas of the rat and the mouse in vivo and in vitro. In the anaesthetised rat, a single intravenous injection of substance P caused an atropine resistant increase in both the basal and caerulein stimulated flow of pancreatic juice and amylase output, but reduced the secretin stimulated pancreatic juice flow. In vitro experiments using superfused mouse pancreatic fragments supported the in vivo result showing that substance P enhanced caerulein stimulated amylase output.     

Mediation of acetylcholine and substance P induced contractions by myosin light chain phosphorylation in feline colonic smooth muscle

OBJECTIVES: To determine the role of myosin light chain phosphorylation in feline colonic smooth muscle contraction. SAMPLE POPULATION: Colonic tissue was obtained from eight 12- to 24-month-old cats. PROCEDURE: Colonic longitudinal smooth muscle strips were attached to isometric force transducers for measurements of isometric stress. Myosin light chain phosphorylation was determined by isoelectric focusing and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Stress and phosphorylation were determined following stimulation with ACh or SP, in the absence or presence of a calmodulin antagonist (W-7; 0.1 to 1.0 mM), myosin light chain kinase inhibitor (ML-9; 1 to 10 microM), or extracellular calcium free solutions. RESULTS: Unstimulated longitudinal colonic smooth muscle contained low amounts (6.9+/-3.2%) of phosphorylated myosin light chain. Phosphorylation of the myosin light chains was dose and time dependent with maximal values of 58.5% at 30 seconds of stimulation with 100 microM Ach and 60.2% at 45 seconds of stimulation with 100 nM SP Active isometric stress development closely paralleled phosphorylation of the myosin light chains in ACh- or SP-stimulated muscle. W-7 and ML-9 dose dependently inhibited myosin light chain phosphorylation and isometric stress development associated with ACh or SP stimulation. Removal of extracellular calcium inhibited myosin light chain phosphorylation and isometric stress development in ACh-stimulated smooth muscle. CONCLUSIONS AND CLINICAL RELEVANCE: Feline longitudinal colonic smooth muscle contraction is calcium-, calmodulin-, and myosin light chain kinase-dependent. Myosin light chain phosphorylation is necessary for the initiation of contraction in feline longitudinal colonic smooth muscle. These findings may prove useful in determining the biochemical and molecular defects that accompany feline colonic motility disorders.     

Early dexamethasone treatment after implantation of a sciatic-nerve cuff decreases the concentration of substance P in the lumbar spinal cord of rats with neuropathic pain

The main purpose of this study was to evaluate the effects of early dexamethasone treatment on pain-related peptides at an early stage in the development of neuropathic pain induced by implantation of a sciatic nerve cuff in Sprague Dawley rats (body weight 250 to 350 g). The rats were tested for touch sensitivity with the use of von Frey filaments before and 3 d after cuff implantation (n = 12) or sham surgery (n = 6). Half of the cuff-implanted rats received dexamethasone, 1 mg/kg intraperitoneally, 1 h after surgery. Spinal cords were collected on the 3rd day after surgery, and the lumbar enlargement was processed for the detection of selected peptides (neurotensin, substance P, cholecystokinin [CCK], vasoactive intestinal peptide, and calcitonin gene-related peptide) by means of liquid chromatography and tandem mass spectrometry. The right sciatic nerve of each rat was collected, fixed, and stained for histopathological evaluation. Except for neurotensin, all the peptides showed an increased concentration with neuropathic pain; however, the differences were significant (P < 0.05) only for substance P and CCK. In the animals treated with dexamethasone, mechanical allodynia was less pronounced (P < 0.01), and only the concentration of substance P was decreased significantly (P < 0.05). Sciatic nerve sections showed a decrease in C (P < 0.01) and Adelta (P < 0.03) fibres with neuropathic pain and a nearly normal percentage of C fibres after dexamethasone treatment. The dexamethasone-treated animals also had less inflammation detectable microscopically at the nerve constriction site compared with cuff-implanted animals that were not treated with dexamethasone. Our results suggest that in the early stages of neuropathic pain induced by an inflammatory process, dexamethasone may be a useful treatment and that substance P plays an important role in pain perception.