Effects of opioid receptor blockade on defensive behavior elicited by electrical stimulation of the aversive substrates of the inferior colliculus in Rattus norvegicus (Rodentia, Muridae)

RATIONALE: Electrical or chemical stimulation of some structures of the midbrain tectum, such as the dorsal periaqueductal gray matter, deep layers of the superior colliculus and inferior colliculus induce fear and flight behavior. These structures constitute the main neural substrates commanding defensive behavior in brainstem. Many neurotransmitters are implicated in the modulation of aversion at the mesencephalic level. OBJECTIVE: The aim of this work is to investigate the involvement of opioid mechanisms in modulation of defensive behavior in dorsal mesencephalon. METHODS: Male Wistar rats were fixed in a stereotaxic frame and a chemitrode was implanted into the midbrain, targeted to the central nucleus of the inferior colliculus. In the present study, the effects of peripheral and central administration of naloxone, naltrexone or naloxonazine on aversive thresholds (freezing and escape reactions) elicited by electrical stimulation of the midbrain tectum were determined. RESULTS: Peripherally and centrally administered naloxone caused a significant increase in the freezing and flight thresholds elicited by electrical stimulation of the aversive substrates of the inferior colliculus. These effects were confirmed by peripheral and central administration of naltrexone and by microinjections of naloxonazine in inferior colliculus. CONCLUSIONS: These findings suggest that endogenous opioids are involved in the modulation of the aversive behavior elicited by midbrain tectum stimulation. Since microinjections of naloxonazine in the central nucleus of the inferior colliculus caused a significant increase in the aversive thresholds elicited by electrical stimulation of this structure, it is possible that micro1 opioid receptor located in this nucleus may be critically implicated in this neural circuitry.     

慢性充血性心力衰竭心气虚证与心阴不足证患者sEDF含量变化的临床意义

目的：观察慢性充血性心力衰竭中心气（血）虚证和心阴不足证患者血清内源性洋地黄因子含量的变化,探讨其临床意义。方法：以放免法测定正常人与慢性充血性心动力衰竭患者中心气（血）虚组与心阴不足组内源性洋地黄因子的含量。结果：心气（血）虚患者内源性洋地黄因子含量比心阴不足型显著下降（P＜0．01）。结论：内源性洋地黄因子分泌减少可能是导致中医心气（血）不足的主要原因之一,而心阴不足证患者内源性洋地黄因子含量比心气（血）虚证患者降低程度小,提示在中西医结合治疗中对前类患者使用洋地黄药物效果可能更好,而对后类患者应谨慎使用洋地黄类药物。     

Ultrastructural Changes and Glutathione Depletion in the Skeletal Muscle Induced by Protein Malnutrition

Ultrastructural changes and glutathione level were investigated in the pectoralis muscle of rats fed a low-protein diet. Electron microscopy demonstrated the ultrastructural changes of occasional myofibrils affected with protein deficiency that were characterized with the streaming and/ or disruption of the Z-line and disintegration of sarcomeric striation. In the affected sarcomeres, sarcomere length was often elongated and fragmented thick filaments were present together with dense amorphous materials flowing from the damaged Z-line. Glutathione level of muscle in the low-protein diet group (5%casein) was reduced to about one-third of that in the control diet group (20% casein). The study suggests that depletion of glutathione by protein malnutrition is responsible for inducing myofibrillar damage through the excess leaking of Ca 2+ into the cytosol.     

含糖输液中热原加热灭活方法

对含５ ％ 或１０ ％ 葡萄糖注射液，先以１１５ ℃压力蒸汽加热处理４０ ｍｉｎ ，放置≥２４ ｈ ，再以１００ ℃加热处理４０ ｍｉｎ 。经检测，输液中热原被灭活，５ － 羟甲基糠醛量≤０ ．２４（ 吸光度值） ，符合我国《药典》规定（ ≤０ ．３２） 。     

Influence of free thyroid hormone levels on the TSH response to TRH in endogenous depression

The TSH response to TRH (Δ_maxTSH) and the serum concentrations of free thyroxine (FT₄), 3,5,3′-, and 3,3′,5′-triiodothyronine (FT₃, and FrT₃) were studied in two groups of patients with endogenous depression before and after clinical recovery following electroconvulsive treatment (ECT). Before ECT, the patients from group 1 (n = 17) had a reduced Δ_maxTSH (p < 0.01), which after ECT rose to values not different from those found in controls. FT₄ levels were elevated before ECT (p < 0.01), and they decreased after ECT (p < 0.05) to levels similar to those found in controls. FT₃ and FrT₃ levels were not different from the control values, but FrT₃ decreased during ECT (p < 0.01). In group 2 (n = 19), Δ_maxTSH was reduced both before (p < 0.02) and after (p < 0.01) ECT. FT₄ levels were increased both before and after ECT (p < 0.02). Both parameters were unaffected by ECT.

The data are compatible with the assumption that the decreased TSH response to TRH found in patients with endogenous depression is secondary to an increase in circulating FT₄.     

Activation of brain regions of rats during fever

The central nervous structures involved in febrile responses were investigated in conscious rats by means of the 2-deoxy-D-[14C]glucose autoradiographic technique. An intravenous injection of endogenous pyrogen prepared from rabbit white blood cells induced a significant rise in the rectal temperature of rats accompanied by a decrease in the skin temperature. According to autoradiographs, significant increases in metabolic activity were observed in the lateral preoptic area, posterior part of dorsomedial thalamus, posterior hypothalamus and the red nucleus during an induced fever. Because of the close relationship between metabolic activity and brain function, these regions are considered to compose the neural components directly or indirectly related with the febrile responses.     

Identification of a RELIK orthologue in the European hare (Lepus europaeus) reveals a minimum age of 12 million years for the lagomorph lentiviruses

The retroviral genus Lentivirus comprises retroviruses characterised from five mammalian orders. Lentiviruses typically undergo rapid rates of evolution, a feature that has allowed recent evolutionary relationships to be elucidated, but has also obscured their distant evolutionary past. However, the slowdown in the rate of evolution associated with genome invasion, as has occurred in the European rabbit, enables longer-term lentiviral evolutionary history to be inferred. Here we report the identification of orthologous RELIK proviruses in the European hare, demonstrating a minimum age of 12 million years for the lagomorph lentiviruses. This finding indicates an association between lentiviruses and their hosts covering much of the evolutionary history of the lagomorphs, and taking place within species with a worldwide distribution.     

纳洛酮治疗急性重型颅脑损伤的临床疗效观察

目的 为了观察纳洛酮对重症脑损伤的临床治疗效果。方法 选择GCS5－8分患30例，每天应用纳洛酮4．8mg克；随机以30例同等伤情、常规治疗病例作为对照。比较观察意识觉醒、血液流变学及临床征象。结果 纳洛酮治疗后，病人觉醒天数缩短，外伤后脑血管痉挛发生率、血液粘滞度降低，伤残率减少。结论 纳洛酮对于内源性阿片肽引起的生理功能的应激性疾病起效快，作用可靠，其使用中未见有毒副作用。     

纳洛酮在乙型脑炎治疗中的意义

目的 :研究乙脑的发病与内源性阿片肽的关系 ,以及阿片肽拮抗剂纳洛酮治疗乙脑的机制和疗效。方法 :治疗组 5 6例应用纳洛酮 0 .0 2mg (kg·次 ) ,每 6～ 8h 1次 ,3～ 5d ;对照组 5 0例未用 ,余治疗相同。观察疗效 ,同时检测急性期和恢复期的血浆和CSF内源性阿片肽含量。结果 :治疗组疗效显著 ,且急性期时血浆和CSF内源性阿片肽明显高于正常值 (P <0 .0 1 ) ,至恢复期时显著下降 (P <0 .0 1 ) ,治疗组比对照组下降更明显。结论 :乙脑的发病与内源性阿片肽释放增加有关 ,纳洛酮治疗后可使内源性阿片肽下降 ,是治疗乙脑的有效药物之一。     

Choline increases endogenous GABA release in rat hippocampus by a mechanism sensitive to hemicholinium-3

Summary The effects of choline (Ch) on the spontaneous release of endogenous 7-aminobutyric acid (GABA) and of ³H-GABA were studied in superfused rat hippocampal synaptosomes. Choline enhanced in a concentration-dependent way the release of endogenous GABA but did not affect that of the radioactive aminoacid. The effect of Ch was not antagonized by atropine or mecamylamine; moreover, it was not mimicked by acetylcholine, oxotremorine or carbachol. The Ch-induced GABA release was counteracted by hemicholinium-3. Thus the release of endogenously synthesized GABA (but not that of the aminoacid taken up) may be regulated by Ch through a mechanism involving penetration into the releasing terminal through a Ch uptake system. Send offprint requests to M. Raiteri