Electron microscopic localization of enkephalin in the median eminence and the adenohypophysis of the guinea-pig

By using different immunocytochemical methods, it has been possible to define the ultrastructural localization of enkephalins in the median eminence and in the adenohypophysis of the guinea-pig. In the median eminence the staining was essentially confined to the granules of nerve terminals in the palissade zone. When the immunocytochemical procedure occurred before embedding the tissue, the granules displayed several electron-dense dots revealing the presence of enkephalin. In addition this technique made it possible to observe a peripheral staining of the small vesicles. In the adenohypophysis three cell types bound antisera to leucine or methionine-enkephalins: the gonadogrophs, the thyrotrophs and the corticotrophs. In all three cases the reaction product was obtained on the granules.It is proposed that enkephalins might act on the pituitary secretions not only at the hypothalamic level but also at the pituitary level.     

Differential regulation of collagen secretion by kinin receptors in cardiac fibroblast and myofibroblast

Kinins mediate their cellular effects through B1 (B1R) and B2 (B2R) receptors, and the activation of B2R reduces collagen synthesis in cardiac fibroblasts (CF). However, the question of whether B1R and/or B2R have a role in cardiac myofibroblasts remains unanswered.

Methods

CF were isolated from neonate rats and myofibroblasts were generated by an 84 h treatment with TGF-β1 (CMF). B1R was evaluated by western blot, immunocytochemistry and radioligand assay; B2R, inducible nitric oxide synthase (iNOS), endothelial nitric oxide synthase (eNOS), and cyclooxygenases 1and 2 (COX-1, and COX-2) were evaluated by western blot; intracellular Ca^+ 2 levels were evaluated with Fluo-4AM; collagen secretion was measured in the culture media using the picrosirius red assay kit.

Results

B2R, iNOS, COX-1 and low levels of B1R but not eNOS, were detected by western blot in CF. Also, B1R, B2R, and COX-2 but not iNOS, eNOS or COX-1, were detected by western blot in CMF. By immunocytochemistry, our results showed lower intracellular B1R levels in CF and higher B1R levels in CMF, mainly localized on the cell membrane. Additionally, we found B1R only in CMF cellular membrane through radioligand displacement assay. Bradykinin (BK) B2R agonist increased intracellular Ca²⁺ levels and reduced collagen secretion both in CF and CMF. These effects were blocked by HOE-140, and inhibited by L-NAME, 1400W and indomethacin. Des-Arg-kallidin (DAKD) B1R agonist did not increase intracellular Ca²⁺ levels in CF; however, after preincubation for 1 h with DAKD and re-stimulation with the same agonist, we found a low increase in intracellular Ca²⁺ levels. Finally, DAKD increased intracellular Ca²⁺ levels and decreased collagen secretion in CMF, being this effect blocked by the B1R antagonist des-Arg9-Leu8-kallidin and indomethacin, but not by L-NAME or 1400 W.

Conclusion

B1R, B2R, iNOS and COX-1 were expressed differently between CF and CMF, and collagen secretion was regulated differentially by kinin receptor agonists in cultured CF and CMF.     

亮氨酸转运核糖核酸1基因突变与线粒体病

目的 在线粒体疾病中,亮氨酸转运核糖核酸1(tRNA1)基因突变是最为常见的致病突变之一,我们回顾性分析亮氨酸tRNA1基因突变所导致患者的临床特征和病理特点,以及与突变负荷的关系.方法 经测序确认的亮氨酸tRNA1基因突变(MTTL1*3243A>G,3271A>T)患者18例.回顾性分析线粒体亮氨酸转运核糖核酸1(MTTL1)突变患者的临床表型、病理学特点、遗传和分子生物学特征.结果 MTTL1突变导致线粒体腩肌病伴高乳酸血症和脑卒中样发作(MELAS)表型最多(13例),其次可见于糖尿病(1例)、进行性眼外肌麻痹(1例)以及Leigh综合征(1例)和未分类的线粒体病(2例).多数患者为散发,有5例患者为母系遗传.表型与突变负荷无显著相关.结论 MTTL1基因突变具有高度的表型变异,表型与突变负荷无明显关系.     

Enkephalin immunoreactive nerve fibres and cell bodies in sympathetic ganglia of the guinea-pig and rat.

The occurrence and distribution of enkephalin-like immunoreactivity was studied by light microscopy, using an indirect fluorescent-labelled antibody technique, in the superior cervical ganglion, the inferior mesenteric ganglion and the coeliac-superior mesenteric ganglion complex of the guinea-pig and rat. In theguinea-pig a very dense network of enkephalin-positive fibres was observed in the inferior mesenteric ganglion and a less dense one in the coeliac-superior mesenteric ganglion complex. In both ganglia some ‘small intensely fluorescent’ cells were immunoreactive. In the superior cervical ganglion only few fluorescent fibres were seen but several ‘small intensely fluorescent’ cells were enkephalin-positive. In therat the inferior and coeliac-superior mesenteric ganglia contained medium-dense networks of enkephalin-positive fibres. An irregularly distributed network of fluorescent fibres was observed in the superior cervical ganglion, where also several principal ganglion cells were enkephalinimmunoreactive, particularly after colchicine treatment. These findings indicate the presence of several peripheral neuron systems containing enkephalin or a similar peptide.Several antisera raised to methionine- and leucine-enkephalin as well as to α- and β-endorphin were used. Some of these antisera were compared by incubating sections of the inferior mesenteric ganglion with increasing dilutions of antiserum as well as with antisera treated with increasing concentrations of methionine- and leucine-enkephalin, respectively. On the basis of these findings the problem of differentiating between methionine- and leucine-enkephalin is discussed.     

缺血预处理对离体大鼠肺缺血再灌注损伤中性粒细胞的影响

目的　研究缺血预处理 (IP)对离体大鼠肺缺血再灌注损伤中性粒细胞的影响。方法　建立离体大鼠肺缺血再灌注损伤模型。 18只S -D大鼠随机分为 3组 ,每组 6只。①对照组 (CON) :持续平衡灌注 60min ;②缺血再灌注组 (IR) :平衡 3 0min后 ,给予缺血 45min和再灌注 3 0min ;③缺血预处理组 (IP) :平衡 10min后 ,先给予连续 2次 5min缺血、5min再灌注的预处理 ,再行缺血 45min和再灌注 3 0min。测定缺血前和再灌注末灌注液中丙二醛 (MDA)、超氧化物歧化酶 (SOD)、肿瘤坏死因子 -α(TNF -α)和白细胞数量 ,测定肺组织髓过氧化物酶 (MPO)活性、湿 /干重比 (W /D)。结果　与CON组和缺血前相比 ,IR导致再灌末MDA含量、TNF -α含量、MPO活性和W/D均明显升高 (P <0 .0 5) ,而SOD活性则显著下降 (P <0 .0 5)。缺血预处理能明显减少再灌后MDA、MPO和W/D的增加 ,提高SOD的活性 (P <0 .0 5) ,但对TNF -α则无明显的影响 (P >0 .0 5)。结论　缺血预处理能明显抑制离体大鼠肺缺血再灌注导致的中性粒细胞在肺内的聚集 ,抑制炎性反应 ,减轻肺损伤     

内源性阿片肽在正常妊娠和分娩中的变化

目的：观察内源性阿片肽在正常妊娠及分娩各阶段含量的变化规律。方法：采用神经肽放射免疫测定方法，测定50例正常未孕妇女（对照组）、45例正常妊娠妇女（早孕、中孕及晚孕3个时间段）、45例正常平产妇女（潜伏期、活跃期及分娩即刻3个时间段）和45例产后妇女（2h、24h2个时间点）血浆中3种内源性阿片肽（β－内啡肽、强啡肽A1－13及亮啡肽）含量的变化。结果：妊娠、分娩不同阶段，血浆中3种内源性阿片肽含量均有不同程度的变化；β－内啡肽含量在妊娠期略有上升，分娩期开始显著增高，至分娩即刻升到最高，升高程度是3种肽中最高的且产后24h降至正常；强啡肽A1－13含量从晚期妊娠开始显著升高，并上升至分娩即刻，分娩后渐下降，整个变化趋势平稳；亮啡肽含量在早孕时显著升高，而中、晚期降至正常，直至分娩即刻时再次显著升高，产后24h继续上升至最高。结论：内源性阿片肽在正常妊娠及分娩各时期有着重要的调节功能。     

阿片成瘾者的脑啡肽改变与药物依赖

本文用放射免疫法对健康组30例,阿片成瘾组300例进行了血浆中脑啡肽(LEK)浓度测定。结果显示阿片成瘾治疗前、后组LEK均较健康组升高,提示:正常人血浆中存在着一定浓度的LEK以维持正常的生理功能。滥用毒品造成LEK分泌失调,结果使痛阈与正常情绪的维持完全依赖毒品。本文认为阿片成瘾者的LEK改变是出现药物依赖的病理基础,成瘾的作用机理可能是阿片模拟内源性阿片类作用。成瘾的危险是用毒品后的欣快感所致的人格变态。     

Distribution of vasoactive intestinal polypeptide-, substance P-, enkephalin-and neurotensin-like immunoreactive nerves in the chicken gut during development

The ontogeny and distribution of nerve cell bodies and fibres which contain vasoactive intestinal polypeptide-, substance P-, enkephalin- and neurotensin-like immunoreactivity have been studied in the chicken gastrointestinal tract, using immunocytochemistry. All four peptides were found in nerve fibres, with characteristic distribution patterns, which, in the cases of vasoactive intestinal polypeptide, substance P and methionine enkephalin were similar to those described for the mammalian gut. In addition, many of these fibres were shown to arise from intrinsic neurons, since immunoreactive nerve cell bodies for each of the peptides studied were observed. Neurotensin-immunoreactive nerves were confined to the upper part of the tract and neurotensin immunoreactive cell bodies were only observed in embryonic and newly hatched chicken gut. All four peptides were first observed at 11 days of incubation, or Hamburger-Hamilton stage 37,²⁰ in the upper part of the tract, particularly in the gizzard. Substance P and methionine enkephalin were subsequently seen in more caudal regions, while vasoactive intestinal polypeptide developed from each end of the tract. Adult patterns of immunoreactivity in nerve fibres were achieved during the first week after hatching. A striking observation was that immunoreactive neuronal cell bodies were much more abundant in the gut of young chickens and chicken embryos than in that of adult birds.     

母系遗传糖尿病中线粒体tRNA^leu（UUR）基因突变的研究

为了解线粒体ｔＲＮＡｌｅｕ（ＵＵＲ）基因ｎｔ３２４３Ａ→Ｇ突变在中国人家族性糖尿病中的发生率及该类糖尿病的临床特征，应用聚合酶链反应（ＰＣＲ）结合限制性内切酶酶切分析，对５８例有母亲患病史（第１组）、３２例有父亲患病（第２组）、４８例有兄弟姐妹患病史（第３组）和５０例无家族史（第４组）的糖尿病患者进行该基因的筛查。在第１组和第３组患者中发现５例突变基因阳性者，并对其中２例先证者的家系成员进行临床和基因分析。结果显示该突变在家族中与糖尿病和耳聋共分离。提示这是一种独特的糖尿病亚型，存在于中国人ＩＤＤＭ和ＮＩＤＤＭ群体中，在母系遗传糖尿病中有较高的发生率。