慢性间歇低氧对大鼠颏舌肌细胞线粒体功能的影响及脂联素的干预作用

目的 探讨慢性间歇低氧(CIH)对大鼠颏舌肌细胞线粒体功能的影响及脂联素干预作用.方法 健康雄性Wistar大鼠39只,采用随机数字表法分成健康对照(NC)组、CIH组、CIH脂联素干预组(CIH+Ad组),每组13只.NC组大鼠呼吸正常空气,CIH组与CIH+Ad组均接受CIH环境(CIH 8 h/d,共5周),CIH+Ad组加用经静脉脂联素注射10 μg/次,2次/周,共5周.于实验终止(第35天)时测定并比较各组大鼠血清脂联素浓度、颏舌肌线粒体膜电位、线粒体复合物Ⅰ活性、线粒体复合物Ⅳ活性.结果 CIH组血清脂联素浓度明显低于NC组[(1108±112)ng/ml,(2241±121)ng/ml,P＜0.01];CIH+Ad组高于CIH组[(1889±119)ng/ml]但低于NC组[(2241±121)ng/ml,均P＜0.01].CIH组颏舌肌线粒体膜电位相对值(1.82±0.11)明显低于NC组(2.09±0.14,P＜0.01),CIH+Ad组(1.98±0.09)较CIH组略高但低于NC组,差异均有统计学差异(均P＜0.05).CIH组线粒体复合物Ⅰ、Ⅳ浓度[(35.68±1.73)μmol·min-1·mg-1,(2.37±0.11)nmol·min-1·mg-1]最低,CIH+Ad组[(37.18±1.95)μmol·min-1·mg-1,(2.49±0.09)nmol·min-1·mg-1]及NC组[(39.02±1.38)μmol·min-1·mg-1,(2.81±0.12)nmol·min-1·mg-1]依次增高.NC组与CIH组比较差异有统计学意义(P＜0.01),CIH+Ad组与CIH组和NC组比较差异有统计学意义(均P＜0.05).结论 CIH可致大鼠血清脂联素水平降低,并能显著损伤颏舌肌细胞线粒体功能,补充外源性脂联素能部分改善CIH对大鼠颏舌肌细胞线粒体功能的损伤,提示低脂联素血症可能参与CIH导致的颏舌肌能量代谢障碍.

Abstract：

Objective To investigate the effect of chronic intermittent hypoxia (CIH) on mitochondrial function in genioglossus cells of rats and intervention role of adiponectin (Ad). Methods Thirty-nine healthy male Wistar rats were randomly divided into 3 groups, normal control (NC) group, CIH group and CIH + Ad group with 13 rats in each. Rats in NC group were kept breathing normal air, while rats in both CIH and CIH + Ad groups experienced the same CIH environment ( CIH 8 h/day for successive 5 weeks). However, rats in CIH + Ad group was given intravenous Ad supplement at the dosage of 10 μg,twice a week for sucessive 5 weeks. At the end of experiment ( day 35 ), the levels of plasma adiponectin,mitochondrial membrane potential activities of respiratory chain complexes Ⅰ and Ⅳ in mitochondrion of genioglossus cells were compared among different groups. Results Serum Ad level was significantly lower in CIH group than that in NC group [(1108 ± 112) ng/ml vs (2241 ± 121) ng/ml, P＜0.01 ]. Serum Ad level in CIH + Ad group [ ( 1889 ± 119) ng/ml] was significantly higher than that in NC group but lower than that in CIH group ( all P ＜ 0. 01 ). Mitochondrial membrane potential was significantly lower in CIH group than that in NC group [ ( 1.82 ± 0. 11 ) vs (2. 09 ± 0. 14), P ＜ 0. 01 ]. Mitochondrial membrane potential in CIH + Ad group ( 1.98 ± 0. 09) was higher than that in CIH group but lower than that in NC group ( all P ＜ 0. 05 ). The concentrations of mitochondrial respiratory chain complexes Ⅰ and Ⅳ in CIH group ( 35.68 ± 1.73 ) μmol · min - 1 · mg- 1 and (2. 37 ± 0. 11 ) nmol · min - 1 ·mg - 1, respectively) were the lowest but became higher from CIH + Ad group [ (37. 18 ± 1.95) μ mol· min-1 · mg-1 and (2. 49 ±0.09) nmol · min-1 ·mg-1 ,respectively] to NC group (39.02 ± 1.38) μmol · min-1 · mg-1 and (2. 81±0. 12) nmol · min-1 ·mg-1 ,respectively), with a significant difference between NC and CIH groups ( P ＜ 0. 01 ), between CIH + Ad and CIH groups ( P ＜ 0. 05 ), as well as between CIH + Ad and NC groups (P ＜ 0. 05 ). Conclusion CIH could lead to hypoadiponectinemia and impaired mitochondrial function in genioglossus cells of rats. Since such changes could be partially improved by supplement of adiponectin, it was suggested that hypoadiponectinemia might be involved in CIH-induced impairment of genioglossus energy metabolism.     

脂联素缓解慢性间歇低氧所致的颏舌肌线粒体损伤

目的 探讨慢性间歇低氧（CIH）对颏舌肌线粒体的损伤以及脂联素（Ad）的干预作用及机制。方法 45只成年Wistar大鼠随机分为3组：正常对照（NC）组、CIH组及CIH＋Ad组,每组15只。CIH组及CIH＋Ad组的大鼠暴露于同样的间歇低氧环境（8h/d,5周）,而NC组的大鼠则只暴露于正常空气。此外,CIH＋Ad组的大鼠还接受2次/周的Ad静脉注射。结果 与NC组相比,CIH组大鼠的颏舌肌出现以下的损伤性表现：线粒体数量减少、线粒体结构损伤伴Ⅰ型纤维减少（P＜0.05）。但与CIH组相比,CIH＋Ad组的大鼠颏舌肌线粒体结构和功能改善且Ⅰ型纤维的数量有所增加（P＜0.05）。与NC组相比,CIH组大鼠颏舌肌显示LKB1-AMPK-PGC1-α通路蛋白表达下降（P＜0.05）,而CIH＋Ad组较CIH组有明显改善（P＜0.05）。结论 CIH可引起颏舌肌线粒体等损伤,而补充外源性Ad可能通过调节AMPK通路改善上述CIH诱导的颏舌肌病理改变。     

慢性间歇低氧对大鼠颏舌肌超微结构和线粒体功能的影响

目的 探讨慢性间歇低氧(CIH)对大鼠颏舌肌细胞超微结构及线粒体功能的影响及脂联素(Ad)的干预作用.方法 健康雄性Wistar大鼠39只,随机分成健康对照组(A)、CIH组(B)、CIH加Ad干预组(C),每组13只.A组大鼠保持呼吸空气,B组与C组均接受CIH环境(CIH 8 h/d,共5周),但C组同时经静脉注射...     

脂联素抑制内质网应激干预慢性间歇性缺氧所致肾损伤

目的探讨脂联素(Ad)对慢性间歇性缺氧(CIH)所致肾损伤的干预作用及相关机制。方法 60只成年Wistar大鼠随机分成4组:正常对照(NC)组、NC+Ad组、CIH组和CIH+Ad组。其中CIH组和CIH+Ad组大鼠接受CIH处理4个月。其余2组接受正常空气处理,同时NC+Ad组和CIH+Ad组大鼠接受Ad(10l人開)治疗,每周2次,持续4个月。荧光显微镜下观察活性氧(ROS)的水平。TUNEL染色检测肾脏细胞凋亡情况。Western blotting检测各组大鼠肾脏组织中GRP78、CHOP、IRE1、PERK、pro-ATF6蛋白的表达,以反映各组大鼠内质网应激情况。采用SPSS 17.0软件进行统计学分析。计量资料用均数±标准差(±s)表示,组间比较用t检验。结果实验满4个月时,组间比较示各参数在NC与NC+Ad组间差异均无统计学意义(P均0.05)。与NC组和NC+Ad组比较:(1)ROS水平在CIH组显著增高,而CIH+Ad组低于CIH组,但仍高于NC组和NC+Ad组(尸均0.05);(2)肾细胞凋亡率和反映凋亡的caspase-12和caspase-3蛋白水平在CIH组明显增加,CIH+Ad组较CIH组明显减少,但仍然高于NC组和NC+Ad组(P均0.05);(3)CIH组肾脏组织的GRP78、CHOP、IRE1、PERK蛋白水平明显增加,在CIH+Ad组明显减少,但仍高于NC组和NC+Ad组(P均0.05);pro-ATF6蛋白水平在CIH组明显降低,在CIH+Ad组有所增加,但仍然低于NC组和NC+Ad组(P均0.05)。结论 CIH可以通过激活ROS和ERS相关的细胞凋亡途径导致肾脏损伤,而补充外源性Ad后,可能通过抑制ROS,进而抑制ERS,保护肾脏细胞。     

间歇低氧对大鼠颏舌肌运动皮质区经颅磁刺激反应的影响

目的 应用经颅磁刺激技术探讨间歇低氧对颏舌肌运动皮质区的影响.方法 选取Sprague-Dawley雄性大鼠80只按照随机数字表法分为正常对照组(10只)和间歇低氧组(各低氧组10只),应用经颅磁刺激刺激两组大鼠颏舌肌运动皮质区并记录刺激后的反应,测量并比较反应潜伏期和幅度,多组间数据比较采用单因素方差分析.结果 大鼠大脑皮质前外侧区是颏舌肌运动皮质区最佳经颅磁刺激位点.与对照组(5.20 ±0.64)ms,(1.21±0.53) mV]相比,间歇低氧大鼠颏舌肌运动皮质区的经颅磁刺激反应潜伏期在低氧第1天[( 4.90±0.54) ms]和第14天[(4.64±1.71)ms]显著缩短,差异有统计学意义(F=3.294,P＜0.01);反应幅度在低氧第1天[(2.28±0.57)mV]和第7天[ (1.89 ±0.20)mV]显著增高(F=1.905,P＜0.05).结论 间歇低氧可以引起大鼠颏舌肌运动皮质区的反应性增加.     

糖尿病一级亲属脂联素和瘦素与胰岛素抵抗的相关性

目的　了解2型糖尿病(T2DM)患者一级亲属非糖尿病个体中瘦素、脂联素水平的变化,研究瘦素、脂联素与胰岛素抵抗(IR)的相关性。　方法　选取 153 例糖耐量正常者,其中无家族史的正常对照(NC)者41例,单纯父亲为糖尿病的一级亲属 36 例,单纯母亲为糖尿病的一级亲属 45例,双亲均为糖尿病的一级亲属31例。测定所有受试者血脂、血糖、胰岛素、瘦素、脂联素。　结果　T2DM患者一级亲属中3个亚组瘦素水平[(11±6)μg/L、(10±5)μg/L、(11±9)μg/L]高于 NC组[(8±6)μg/L](P<0 05),胰岛素抵抗指数(IRI)[(3.0±1.4)、(2.9±1.5)、(3 3±1 5)]高于 NC组[(2.0±0.8)](P<0.05),脂联素水平[(11±6)g/L、(10±6)g/L、(12±8) g/L]低于 NC组[(17±11)g/L](P<0.05)。一级亲属各组间的代谢指标差异无统计学意义。体质指数、瘦素、腰围、腰臀比、脂联素是 IRI的独立危险因素。　结论　T2DM患者一级亲属 IR程度显著高于无家族史者。脂联素与瘦素可能联合影响T2DM患者一级亲属的 IR程度。     

脂联素对大鼠慢性间歇性低氧所致心肌重塑的影响

目的：探讨慢性间歇性低氧（chronic intermittent hypoxia,CIH）对心肌重塑的影响及脂联素（adiponectin, Ad）的干预作用。方法将45只Wistar大鼠随机分为3组：正常对照组（NC）,CIH组和CIH＋Ad组。CIH 35d后,使用马松染色分析方法检测左室纤维化程度及使用Western blot方法来衡量Ⅰ型胶原蛋白、Ⅲ型胶原蛋白和TGF-β/smad2/3通路蛋白的表达。通过RT-PCR方法来研究基质金属蛋白酶-2（MMP2）/基质金属蛋白酶的组织抑制剂-2（TIMP-2）的mRNA表达比值情况。结果慢性间歇性低氧处理后,CIH组左心室的纤维化程度显著高于NC组和CIH＋Ad组（P＜0.05）,但NC组和CIH＋Ad组之间差异具有统计学意义（P＜0.05）。CIH组Ⅰ型胶原蛋白和Ⅲ型胶原蛋白和MMP2/TIMP-2的mRNA比值表达最高,NC组表达最低,CIH＋Ad组居中,3组之间均差异具有统计学意义（P＜0.05）。TGF-β/smad通路蛋白在CIH组中表达显著高于NC组和CIH组（P＜0.05）,且NC组和CIH＋Ad组差异具有统计学意义（P＜0.05）。结论慢性间歇性低氧可引起左室重构,而Ad可能通过抑制TGF-β/smad2/3通路改善此损害。     

西南地区人群尿脂联素水平与2型糖尿病合并冠心病的相关性

目的探讨西南地区人群尿脂联素水平与2型糖尿病(T2DM)合并冠心病(CHD)的相关性。方法采用酶联免疫吸附试验(ELISA)测定23例T2DM患者(T2DM组)和23例T2DM合并CHD患者(DC组)及38例健康对照(NC组)的血、尿脂联素水平,探讨各组脂联素与体重指数(BMI)、腰臀比(WHR)、血脂、血糖、颈动脉中层厚度(IMT)、尿白蛋白/肌酐(ACR)等的关系。结果 DC组尿脂联素水平较T2DM组及NC组均明显升高(分别为20.91±4.59 vs 17.75±1.90μg/ml,20.91±4.59 vs 13.61±5.74μg/ml,P<0.01),T2DM组较NC组明显升高;DC组血清脂联素水平也明显升高(分别为5.73±1.78 vs 8.43±3.55μg/ml,5.73±1.78 vs 14.46±4.18μg/ml,P<0.01)。线性相关分析表明T2DM组尿脂联素水平与血清脂联素相关,而DC组则还与糖化血红蛋白(Hb A1c)、总胆固醇(TC)、ACR相关,进一步行多元逐步回归分析表明,DC组影响尿脂联素水平的独立危险因素为ACR、Hb A1c及TC是(Y尿脂联素=0.004X ACR+2.83XHBA1C+4.055XTC-30.224)。结论尿脂联素水平改变与T2DM大血管病变有关,其参与了T2DM合并CHD的发生发展。     

戒烟对大鼠血清瘦素、脂联素等炎症因子的影响

目的 通过研究戒烟对大鼠血清瘦素、脂联素、白介素6(IL-6)及C反应蛋白(CRP)水平的影响,探讨瘦素和脂联素等炎症因子在吸烟所致慢性阻塞性肺疾病炎症反应中的作用.方法 雄性Wistar大鼠30只,随机分为吸烟组、戒烟组及对照组,每组各10只.吸烟组每次吸烟10支,每天吸烟2次,每周吸烟6 d,共吸烟20周;戒烟组为吸烟20周后戒烟10周.采用酶联免疫吸附法检测各组大鼠血清瘦素、脂联素及CRP水平,采用双抗体夹心酶联免疫吸附法检测各组大鼠血清IL-6水平.结果 ①与对照组[(128.00±13.25) ng/L]比较,吸烟组[(56.23±8.64)ng/L]及戒烟组[(60.36±7.42)ng/L]血清瘦素水平均降低(P值均<0.05);戒烟组与吸烟组比较差异无统计学意义.②与对照组L(0.369±0.032)μg/L]比较,吸烟组[0.322±0.045)μg/L]血清脂联素水平降低(P<0.05),而戒烟组L(0.333±0.059)μg/L]与对照组、吸烟组比较差异无统计学意义.③与对照组[(23.94±4.44)ng/L]比较,吸烟组[(39.67±3.13)ng/L]及戒烟组[(34.27±7.01)ng/L]血清IL-6水平均升高(P值均<0.05);戒烟组较吸烟组水平降低(P<0.05).④与对照组[(494.49±124.44)μg/L]比较,吸烟组[(809.50±141.66)μg/L]及戒烟组[(632.60±182.85)μg/L]血清CRP水平均升高(P值均<0.05);戒烟组较吸烟组水平降低(P<0.05).⑤脂联素水平分别与IL-6和CRP呈负相关(γ值分别为-0.198、-0.489,P值均<0.05);IL-6水平与CRP呈止相关(γ=0.598,P<0.05).结论吸烟可使大鼠血清瘦素与脂联素水平下降,IL-6与CRP水平升高;戒烟后,瘦素、脂联素水平呈上升趋势,IL-6和CRP水平则相应下降.此外,脂联素水平分别与IL-6和CRP呈负相关.提示瘦素、脂联素等炎症因子可能参与吸烟所致慢性阻塞性肺疾病的炎症反应.     

血清脂肪细胞型脂肪酸结合蛋白及脂联素水平与冠心病的相关性

目的 探讨脂肪细胞型脂肪酸结合蛋白(A-FABP)、脂联素和A-FABP/脂联素比值与冠心病及冠状动脉病变程度的相关性.方法 经冠状动脉造影入选340例患者,分为冠心病组(211例)和非冠心病对照组(129例),用ELISA法测定血清AFABP及脂联素水平,冠状动脉病变程度用病变血管支数和Gensini积分表示.并从上述患者中选取年龄、性别、体质指数相匹配的冠心病及非冠心病者各10例,分离外周血单核细胞,佛波酯刺激为巨噬细胞后取培养上清,用ELISA法测定培养上清液A-FABP及脂联素浓度.结果 (1)冠心病组血清A-FABP水平[18.3(13.2,22.8)μg/L]较非冠心病组[16.4(13.5,20.4)μg/L]高,但差异未达到统计学意义(P=0.088);冠心病组血清脂联素水平低于非冠心病组[13.9(9.8,17.1)mg/L比19.7(14.5,27.6)mg/L,P＜0.05].(2)随着冠状动脉病变支数的增加,血清A-FABP水平呈升高、脂联素水平呈递减趋势;Gensini积分与血清A-FABP呈正相关(r=0.120,P=0.043),与脂联素呈负相关(r=-0.405,P=0.007).(3)冠心病组血清A-FABP/脂联素比值明显高于非冠心病组[(1.51±0.79)μg/mg比(0.89±0.30)μg/mg,P＜0.01];血清A-FABP/脂联素比值与Gensini积分的相关性更明显(r=0.531,P=0.000).(4)冠心病者单核源性巨噬细胞A-FABP/脂联素比值高于非冠心病者[(0.51±0.19)μg/mg比(0.36±0.11)μg/mg,P＜0.05].结论 高A-FABP和低脂联素水平可能是反映严重冠状动脉狭窄的新的血清标记物.A-FABP/脂联素比值较单独A-FABP或脂联素与冠状动脉病变的相关性更好.     

Three layer functional model and energy exchange concept of aging process

Relying on a certain degree of abstraction, we can propose that no particular distinction exists between animate or living matter and inanimate matter. While focusing attention on some specifics, the dividing line between the two can be drawn. The most apparent distinction is in the level of structural and functional organization with the dissimilar streams of ‘energy flow’ between the observed entity and the surrounding environment. In essence, living matter is created from inanimate matter which is organized to contain internal intense energy processes and maintain lower intensity energy exchange processes with the environment. Taking internal and external energy processes into account, we contend in this paper that living matter can be referred to as matter of dissipative structure, with this structure assumed to be a common quality of all living creatures and living matter in general. Interruption of internal energy conversion processes and terminating the controlled energy exchange with the environment leads to degeneration of dissipative structure and reduction of the same to inanimate matter, (gas, liquid and/or solid inanimate substances), and ultimately what can be called ‘death.’ This concept of what we call dissipative nature can be extended from living organisms to social groups of animals, to mankind. An analogy based on the organization of matter provides a basis for a functional model of living entities. The models relies on the parallels among the three central structures of any cell (nucleus, cytoplasm and outer membrane) and the human body (central organs, body fluids along with the connective tissues, and external skin integument). This three-part structural organization may be observed almost universally in nature. It can be observed from the atomic structure to the planetary and intergalactic organizations. This similarity is corroborated by the membrane theory applied to living organisms. According to the energy nature of living matter and the proposed functional model, the decreased integrity of a human body's external envelope membrane is a first cause of the structural degradation and aging of the entire organism. The aging process than progresses externally to internally, as in single cell organisms, suggesting that much of the efforts towards the restoration and maintenance of the mechanisms responsible for structural development should be focused accordingly, on the membrane, i.e., the skin. Numerous reports indicate that all parts of the human body, like: bones, blood with blood vessels, muscles, skin, and so on, have some ability for restoration. Therefore, actual revival of not only aging tissue of the human body's membrane, but the entire human body enclosed within, with all internal organs, might be expected. We assess several aging theories within the context of our model and provide suggestions on how to activate the body's own anti-aging mechanisms and increase longevity. This paper presents some analogies and some distinctions that exist between the living dissipative structure matter and inanimate matter, discusses the aging process and proposes certain aging reversal solutions.     

Unusual responses of nocturnal pineal melatonin synthesis and secretion to swimming: Attempts to define mechanisms

Abstract: The effect of swimming at night on rat pineal melatonin synthesis was compared with that of light exposure at night. Rats were forced to swim at 0030 hr (lights out at 2000 hr) and sacrificed by decapitation 15 and 30 min later, immediately after swimming. Other groups of animals were exposed to white light (650μW/cm²) for 15 and 30 min at same time. Swimming caused a rapid and highly significant drop in the melatonin content in the pineal gland; however, the activity of N-acetyltransferase (NAT), the supposed rate limiting enzyme in the melatonin production, was not changed. Despite the drop in pineal melatonin levels, serum concentrations of the indole remained elevated in the rats that swam. In contrast, melatonin levels in the pineal and serum of light exposed rats fell precipitously, accompanied by a significant suppression of NAT activity. Since we anticipated that the strenuous exercise associated with swimming may induce release of artrial natriuretic peptide (ANP) from the heart, which in turn could cause the release of pineal melatonin, in a second study we injected physiological saline intravenously to stretch the cardiac muscle and release ANP. Three milliliters of normal saline was injected during the day into the jugular vein of anesthetized rats that were pretreated with isoproterenol to stimulate pineal melatonin production. Animals were killed 15 min after the saline injection, and pineal NAT activity and pineal melatonin levels were measured. The saline injections caused no alteration in the elevated levels of either NAT or melatonin. These data suggest that the disparity in pineal NAT activity (which was high) and pineal melatonin (which was low), in animals swum at night, may not be caused by ANP which is released during strenuous exercise such as swimming.     

The immunoneuroendocrine role of melatonin

Abstract: A tight, physiological link between the pineal gland and the immune system is emerging from a series of experimental studies. This link might reflect the evolutionary connection between self-recognition and reproduction. Pinealectomy or other experimental methods which inhibit melatonin synthesis and secretion induce a state of immunodepression which is counteracted by melatonin. In general, melatonin seems to have an immunoenhancing effect that is particularly apparent in immunodepressive states. The negative effect of acute stress or immunosuppressive pharmacological treatments on various immune parameters are counteracted by melatonin. It seems important to note that one of the main targets of melatonin is the thymus, i.e., the central organ of the immune system. The clinical use of melatonin as an immunotherapeutic agent seems promising in primary and secondary immunodeficiencies as well as in cancer immunotherapy. The immunoenhancing action of melatonin seems to be mediated by T-helper cell-derived opioid peptides as well as by lymphokines and, perhaps, by pituitary hormones. Melatonin-induced-immuno-opioids (MHO) and lymphokines imply the presence of specific binding sites or melatonin receptors on cells of the immune system. On the other hand, lymphokines such as -γ-interferon and interleukin-2 as well as thymic hormones can modulate the synthesis of melatonin in the pineal gland. The pineal gland might thus be viewed as the crux of a sophisticated immunoneuroendocrine network which functions as an unconscious, diffuse sensory organ.     

Melatonin and photoperiodic time measurement: Seasonal breeding in the sheep

Abstract: Well-established circadian physiology supports the view that photoperiodic time measurement utilizes the coincidence between the presence of light and a photosensitive phase of a 'biological clock' to alter reproductive status—the so-called external coincidence model of seasonal breeding. In this review, we examine the mechanism whereby photoperiod interacts with presumed suprachiasmatic nuclei activity to allow endogenous melatonin to normally synchronize reproductive activity to the optimal time of year. The Romney Marsh sheep is particularly explored as an experimental model. It is suggested that the on/off activity of seasonal reproduction may be a robust mechanism able to be predictably manipulated by the judicious use of the light/dark cycle and exogenous melatonin, but firmly based on circadian principles.     

Response of rat pineal melatonin to calcium, magnesium, and lithium is circadian stage dependent

Abstract: Herein we documented the response of pineal melatonin production to electrolytes known to be effective on pineal function in view of a possible circadian stage dependence. We studied the release of melatonin by perifused rat pineal glands at 2 different circadian stages corresponding to the middle of the light and dark periods, i.e., respectively, 7 and 19 HALO (Hours After Light Onset, L:D = 12:12). The initial efflux rates were, as expected, much higher in the perifusates of glands removed from rats sacrificed during the dark phase than of those removed during the light phase. After 3 hr of perifusion, melatonin release reached similar levels which were found constant up to the 8th hr of perifusion, whatever the circadian stage. Perifusion of the glands with physiological concentrations for the rat of calcium (5.2 mmol/1) and magnesium (1.34 mmol/1) resulted in a stimulatory effect on the pineal glands removed from rats sacrificed in the middle of the dark period (19 HALO), whereas no effects were observed on the pineal glands removed from rats sacrificed during the light (7 HALO). Lithium (0.28 and 0.55 mmol/1) was ineffective on melatonin release in pineal glands removed 7 and 19 HALO. Our results show differences in the initial efflux rates of melatonin and in the response of perifused pineal glands to calcium and magnesium according to the circadian stage.     

Conservative management of perforated duodenal diverticulum： A case report and review of the literature

Duodenal diverticula are a relatively common condition. They are asymptomatic, unless they become complicated, with perforation being the rarest but most severe complication. Surgical treatment is the most frequently performed approach. We report the case of a patient with a perforated duodenal diverticulum, which was diagnosed early and treated conservatively with antibiotics and percutaneous drainage of secondary retroperitoneal abscesses. We suggest this method could be an acceptable option for the management of similar cases, provided that the patient is in good general condition and without septic signs.     

Changes in connexin43, the gap junction protein of astrocytes, during development of the rat pineal gland

Abstract: The abundance of gap junctions between rat pineal astrocytes formed by connexin43 (Cx43) was studied during development. Levels and distribution of Cx43 were measured by immunoblotting and indirect immunofluorescence, respectively. The amount of Cx43 in cells located within the gland was low until about the 7th postnatal day and increased to adult values between the 14th and 21st days postpartum. Although astrocytes, recognized by their vimentin immunoreactivity, were scarce before birth, they were abundant by the 7th postnatal day suggesting that the low levels of Cx43 found at this age corresponded to a low expression of this protein. Localization of the immunoreactivity to Cx43 and vimentin showed a close correlation, indicating that mature or immature pineal astrocytes form gap junctions made of Cx43. Since Cx43 levels attained their adult values at about the time the innervation and the functional state of the gland reached maturity (2–3 weeks after birth), it is proposed that astrocyte gap junctions are involved in the function of the adult rat pineal gland.