γ-射线与香烟联合处理对仔鼠脑组织神经肽的影响

目的：探讨仔鼠脑组织中神经肽（ＡＶＰ和ＳＳ）含量的变化与低剂量γ－射线、香烟及其联合作用的相互关系。方法：用不同剂量的γ－射线联合不同浓度的香烟烟雾水溶物处理孕鼠,采用放射免疫法（ＲＩＡ）检测仔鼠脑组织ＡＶＰ和ＳＳ的含量。结果：低剂量的γ－射线、香烟烟雾水溶物及其联合作用对仔鼠脑组织ＡＶＰ和ＳＳ含量有一定影响,当孕鼠受不同剂量γ－射线照射及烟雾水溶液浓度达２支／只时,与对照组比较仔鼠脑组织中的ＡＶＰ含量明显降低,ＳＳ含量升高（Ｐ＜０．０１）;低剂量γ－射线与香烟联合明显影响仔鼠脑组织中的ＡＶＰ和ＳＳ的含量,与单独照射组和单独给烟组比较,ＡＶＰ含量的降低及ＳＳ含量的升高有明显的差异（Ｐ＜０．０１）。结论：低剂量的γ－射线与香烟联合影响仔鼠脑组织中的ＡＶＰ和ＳＳ水平,并导致中枢神经系统发育异常     

NO含量与NOS活力对ALT与AST活力影响的研究

目的 研究一氧化氮（Ｎｉｔｒｉｃ ｏｘｉｄｅ;ＮＯ）与一氧化氮合酶（ＮｉｔｒｉｃＯｘｉｄｅ ｓｙｎｔｈａｓｅ;ＮＯＳ）活力对丙氨酸转氨酶（ＡＬＴ）与天冬氨酸氨酶（ＡＳＴ）活力的影响并探讨其机制。方法 对大鼠腹腔注射Ｌ－Ａｒｇ,４ｈ后采血取肝检测ＮＯ含量,ＮＯＳ活力、ＡＬＴ及ＡＳＴ活力并与对照组大鼠对比,ＮＯ定量用硝酸还原酶法、ＮＯＳ测定用分光光度法、ＡＬＴ与ＡＳＴ测定用改良赖氏法（２,４－二硝基苯     

Anti-tumor Activity of Arginine Deiminase from Mycoplasma arginini and Its Growth-inhibitory Mechanism

Two kinds of arginine deiminase (AD, EC 3.5.3.6) were purified from cell extracts of Mycoplasma arginini (a-AD) and Mycoplasma hominis (h-AD), and their enzymic properties and anti-tumor activities were compared. The a-AD enzyme strongly inhibited the growth of mouse hepatoma cell line MH134 in vitro , and its concentration required for 50% growth inhibition (IC₅₀) was estimated to be about 10 ng/ml. The IC₅₀ value of h-AD against the same cell line was estimated to be ahout 100 ng/ml, due to its low enzyme activity under the physiological pH condition, i.e., pH 7.4. These results show that the reaction pH profile of the a-AD was superior to that of the h-AD as an anti-tumor enzyme. Moreover, the effects of l -arginine metabolism-related substances on the anti-tumor activity of the a-AD were examined to study the growth-inhibitory mechanism of this enzyme. The addition of 2 or 4 m M l -arginine restored, in a dose-dependent manner, the growth of mouse MH134 hepatoma and Meth A fibrosarcoma cell lines that had been inhibited by 20 ng/ml of the a-AD. The addition of 2 or 4 m M l -ornithine, which is biosynthesized from l -arginine in the urea cycle and is the starting material in the polyamine-biosynthesis pathway, also partially restored it in a dose-dependent manner. These results indicate that the tumor cell growth inhibition caused by a-AD originates from the depletion of the essential nutrient l -arginine, and that the resulting block of the polyamine-biosynthesis pathway is involved in part in the inhibitory mechanism.     

Oral administration of arginine enhances the growth hormone response to growth hormone releasing hormone in short children

We have evaluated the effect of oral administration of arginine chlorhydrate on the growth hormone response to growth hormone releasing hormone in a group of nine short prepubertal children (six boys and four girls). Arginine chlorhydrate 10 g, administered orally 60 min before an iv bolus injection of growth hormone releasing hormone 1–29, 1 μg/kg, significantly enhanced the growth hormone response to the neuropeptidc, confirming the results of previous studies which used the iv route. Furthermore, our data strengthen the view that the effects of arginine chlorhydrate on growth hormone secretion are mediated by inhibition of endogenous somatostatin release.     

缺氧－再给氧对大鼠胸主动脉环内皮依赖血管舒张反应的影响

生物测定法观察大鼠胸主动脉环经缺氧－再给氧、机械去内皮后，血管内皮分泌内皮细胞舒张因子（ＥＤＲＦ）的能力，ＥＤＲＦ前体Ｌ－精氨酸（Ｌ－Ａｒｇ）及拮抗剂ＮＧ－甲基－Ｌ－精氨酸（Ｌ－ＮＭＭＡ）对大鼠胸主动脉内皮ＥＤＲＦ合成和分泌的影响。发现缺氧－再给氧及去内皮的血管环对乙酰胆碱（Ａｃｈ）的舒张反应明显减弱或丧失，而对硝酸甘油的舒张反应仍保存。Ｌ－Ａｒｇ可加强正常内皮环和缺氧－再给氧环对Ａｃｈ的舒张反应；Ｌ－ＮＭＭＡ则使该作用消失。Ｌ－ＮＭＭＡ和去内皮均使血管环丧失对Ａｃｈ的舒张反应。提示缺氧－再给氧和去内皮分别可使大鼠胸主动脉内皮分泌ＥＤＲＦ机制受损或丧失，提供外源性Ｌ－Ａｒｇ有促使正常内皮和受损内皮合成和释放ＥＤＲＦ的作用。     

Neurohormonal effects of oxytocin and vasopressin receptor agonists on spinal pain processing in male rats

Oxytocin (OT) and arginine vasopressin (AVP) are 2 neuropeptides that display well-known effects on the reproductive system. Although still controversial, oxytocin and vasopressin were demonstrated to exert potent effects on the nociceptive system when administered directly in various central nervous structures. On the other hand, little is known about their peripheral (hormonal) actions on nociception and pain responses. The aim of the present work was to characterize the effects of physiological blood concentrations of OT and AVP on spinal nociception and on pain responses. To do so, growing doses of OT or AVP were administered intravenously and the nociceptive processing by spinal cord neurons was analyzed in anesthetized male rats in vivo. We observed that the action potentials mediated by C-type nociceptive fibers was strongly reduced (antinociception) after intravenous injections of low doses of OT (<5 μg) or AVP (<500 pg), whereas an increase (pronociception) was observed at higher doses. Interestingly, antinociceptive and pronociceptive effects were fully abolished in the presence of the OT receptor antagonist and the AVP receptor antagonist type 1A (V_1A), respectively. We confirmed this result with a behavioral model of forced swim stress-induced analgesia associated with plasmatic release of OT (and not vasopressin). Stress-induced analgesia was transiently lost after i.v. administration of OTR antagonist. Together, the present work provides straightforward evidence that blood levels of OT and AVP modulate nociception, windup plasticity and pain responses. The final target structures explaining these effects remains to be identified but are likely to be C-type nociceptors.     

Early changes of arginine vasopressin and angiotensin II in patients with acute cerebral injury

ＡＤｅｐａｒｔｍｅｎｔｏｆＥｍｅｒｇｅｎｃｙ ,ＳｉｒＲｕｎＲｕｎＳｈａｗＨｏｓｐｉｔａｌ,ＭｅｄｉｃａｌＣｏｌｌｅｇｅ ,ＺｈｅｊｉａｎｇＵｎｉｖｅｒｓｉｔｙ ,Ｈａｎｇｚｈｏｕ 310 0 16 ,Ｃｈｉｎａ(ＨｕａｎｇＷＤ ,ＷｕＳＤ ,ＪｉｎＺＦａｎｄＢａｏＤＧ)ＤｅｐａｒｔｍｅｎｔｏｆＥｍｅｒｇｅｎｃｙ ,ＦｉｒｓｔＡｆｆｌｉａｔｅｄＨｏｓｐｉｔａｌ,ＭｅｄｉｃａｌＣｏｌｌｅｇｅ ,ＺｈｅｊｉａｎｇＵｎｉｖｅｒｓｉｔｙ ,Ｈａｎｇｚｈｏｕ 310 0 0 3 ,Ｃｈｉｎａ(ＹａｎｇＹＭ)ＤｅｐａｒｔｍｅｎｔｏｆＮｅｕｒｏｓｕｒｇ…     

抗氧化剂对脂质过氧化内皮细胞表达细胞粘附分子的影响

为研究一氧化氮合酶抑制剂左旋硝基精氨酸诱导的肺动脉高压大鼠各部位离体血管环对多巴胺－ １ 受体反应性的影响，采用大鼠肺动脉、肠系膜动脉和肾动脉离体血管标本，在去甲肾上腺素收缩血管后，用多巴胺－ １ 受体选择性激动剂非诺多泮使血管舒张，所有实验在吲哚美辛（１０ μｍｏｌＬ） 和普萘洛尔（３ μｍｏｌＬ） 存在下进行。左旋硝基精氨酸组大鼠各动脉对非诺多泮的反应性均有不同程度的降低，以肺动脉最明显，最大舒张占预收缩的百分比为４５．５％ ±４．１％ ，低于对照组的９７．３ ％ ±１０ ．６ ％（ Ｐ＜ ０．０１）；亲合常数为２０４２ ±２２１，低于对照组的４２７４ ．２±５１２（Ｐ＜ ０．０１） ，接近对照组的去内皮水平。肠系膜动脉和肾动脉对非诺多泮的反应性亦有下降，但下降程度明显低于肺动脉。结果提示，内皮依赖性受体介导多巴胺－ １ 的舒张效应降低是左旋硝基精氨酸形成肺动脉高压的因素之一。     

Effect of aspirin on hypothalamic–pituitary–adrenal function and on neuropsychological performance in healthy adults: a pilot study

Rationale  Hypothalamic–pituitary–adrenal axis dysregulation predicts poor clinical and biochemical response to antidepressants. Antiglucocorticoids have therapeutic benefits but most have a troublesome adverse event profile. Aspects of neuropsychological performance, notably working memory, are susceptible to corticosteroid modulation and are impaired in depression. Aspirin has been shown to attenuate the adrenocorticotropic hormone (ACTH) and cortisol response to physiological challenge suggesting its potential to act as an augmenting agent in depression. Objectives  To examine the effect of sub-acute (300 mg daily for 7 days) aspirin pre-treatment on the cortisol awakening response and the effect of acute (600 mg) and sub-acute aspirin on the neuroendocrine and neuropsychological response to the arginine vasopressin analogue, desmopressin. Results  We demonstrated that aspirin pre-treatment did not attenuate the cortisol or ACTH response to desmopressin but, as hypothesised, significantly reduced the cortisol awakening response and improved working memory. Conclusions  Further studies to examine the impact of aspirin on neuropsychological performance and HPA axis function are warranted.     

Role of arginine metabolism in immunity and immunopathology

A heterogeneous set of cells that are commonly grouped as “myeloid cells”, interacts in a complex landscape of physiological and pathological situations. In this review we attempt to trace a profile of the “myeloid connection” through different normal and pathological states, by analyzing common metabolic pathways of the amino acid l-arginine. Myeloid cells exert various, often divergent, actions on the immune response through mechanisms that exploit mediators of this peculiar metabolic pathway, ranging from l-arginine itself to its downstream metabolites, like nitric oxide and polyamines. Various pathological situations, including neoplastic and autoimmune diseases, as well as injury repair and infections are discussed here, showing how l-arginine metabolism is able to play a dual role, both as an active protector and a possible threat to the organism.