阻塞性睡眠呼吸暂停低通气综合征患者血浆白细胞介素-18水平与动脉粥样硬化的关系

目的 探讨阻塞性睡眠呼吸暂停低通气综合征(OSAHS)患者血浆IL-18水平与动脉粥样硬化的关系.方法 选取就诊的男性OSAHS患者52例,年龄26～77岁,分为轻度组16例,中度组18例,重度组18例,另选对照组18例.对其中OSAHS组中20例中重度患者进行持续气道内正压(CPAP)治疗,并检测颈动脉内膜中膜厚度(IMT),测定血浆白细胞介素-18(IL-18)的水平.采用方差分析、配对t检验及Pearson相关分析进行统计学处理.结果 轻度、中度和重度OSAHS组的IL-18水平分别为(352±76)ng/L、(600±84)ng/L和(798±110)ng/L,均明显高于对照组的(250±76)ng/L,且OSAHS各组间均有明显差别.重度OSAHS组颈动脉IMT较对照组和轻度OSAHS组明显增厚.血浆IL-18水平与颈动脉IMT、呼吸暂停低通气指数(AHI)呈显著正相关(r值分别为0.486、0.865,P均＜0.001),与最低脉搏氧饱和度呈显著负相关(r=-0.664,P＜0.001).CPAP治疗后OSAHS患者血浆IL-18水平明显降低,颈动脉IMT未见明显改变.结论 OSAHS患者颈动脉IMT增厚,血浆IL-18水平升高,两者密切相关.血浆IL-18水平升高与OSAHS严重程度相关,OSAHS相关炎症反应可能与动脉粥样硬化的进程相关.CPAP治疗能够改善患者AHI和最低脉搏氧饱和度,降低血浆IL-18水平.     

CPAP治疗对OSAHS及其合并高血压患者CRP和IL-6的影响

目的观察持续气道正压通气(CPAP)治疗对阻塞型睡眠呼吸暂停低通气综合征(OSAHS)及其合并高血压患者血清C-反应蛋白(CRP)和白细胞介素-6(IL-6)的影响。方法选择39例中、重度OSAHS患者和20例对照者进行血清CRP和IL-6水平的检测;对39例OSAHS患者进行CPAP治疗并检测治疗前后血清CRP和IL-6水平。比较OSAHS及合并高血压患者血清CRP和IL-6水平与对照者有无差别以及CPAP治疗后对OSAHS及合并高血压患者血清CRP和IL-6水平有无影响。结果单纯OSAHS组及OSAHS合并高血压组的血清CRP及IL-6水平均高于对照组(P0.05),OSAHS合并高血压组血清CRP及IL-6高于单纯OSAHS组(P0.05),OSAHS患者的血清CRP及IL-6水平分别与睡眠呼吸暂停低通气指数(AHI)呈正相关(r1=0.6 8 3、r2=0.6 0 7,P0.0 1)。经CPAP治疗后单纯OSAHS组及OSAHS合并高血压组血清CRP及IL-6水平较治疗前明显降低(P0.05)。结论 OSAHS患者血清CRP和IL-6增高,存在炎症反应,CPAP治疗能降低患者血清CRP和IL-6的水平,减轻OSAHS患者机体的炎症反应。     

高血压合并阻塞性睡眠呼吸暂停患者CPAP治疗前后血压昼夜节律的变化

目的探讨高血压(HP)合并阻塞性睡眠呼吸暂停(obstructive sleep apnea,OSA)患者持续正压通气(CPAP)治疗前后血压昼夜节律的变化。方法选择2011年8月~2015年2月于南京市鼓楼医院集团仪征医院治疗的HP合并OSA患者60例。CPAP治疗前后行24 h动态血压监测,比较患者治疗前后睡眠呼吸暂停低通气指数(AHI)、最低血氧饱和度(Sa O_2)、平均Sa O_2、24 h平均舒张压(24h DBP),24 h平均收缩压(24 h SBP),白天平均舒张压(d DBP),白天平均收缩压(d SBP),夜间平均舒张压(n DBP),夜间平均收缩压(n SBP)。结果治疗前,AHI、最低Sa O_2和平均Sa O_2分别为(45.2±10.8)次/h、(78.2±1.3)%和(91.2±1.5)%;治疗后为(28.3±8.6)次/h、(85.4±3.2)%和(93.7±1.6)%,治疗后与治疗前相比AHI下降,最低Sa O_2和平均Sa O_2升高,差异具有统计学意义(P均0.05)。治疗后,患者的24 h SBP、24 h DBP、d SBP、d DBP、n SBP及n DBP值均低于治疗前,差异有统计学意义(P均0.05)。结论高血压合并阻塞性睡眠呼吸暂停患者存在血压昼夜变化异常,CPAP治疗可改善患者睡眠质量和血压。     

持续气道正压通气对冠心病合并阻塞性睡眠呼吸暂停患者血压和昼间嗜睡的影响

目的:探讨持续气道正压通气(CPAP)对冠心病合并阻塞性睡眠呼吸暂停(OSA)患者血压和昼间嗜睡的影响.方法:入选24例冠心病合并中重度OSA的患者(简称CPAP组),进行1个月的CPAP治疗加最优化的药物治疗;同时选择24例匹配的患者作为对照组,仅给予最优化的药物治疗.基线时记录所有患者的人口学特征、多导睡眠监测的数据等.治疗1个月后,复查两组患者的诊室血压、心率、Epworth嗜睡评分等.结果:与对照组相比,CPAP组舒张压降低,两组的变化值比较差异有统计学意义(CPAP组Δ-5.1±6.5 vs对照组Δ-0.8±6.0(P=0.023);并改善Epworth嗜睡评分(CPAP组Δ-5.2±3.1 vs对照组Δ-0.5±3.2,P<0.001).结论:对于最优化药物治疗的冠心病合并中重度OSA的患者,1个月的CPAP治疗可以显著降低晨起舒张压,改善昼间嗜睡.     

脑梗死患者阻塞性睡眠呼吸紊乱与脑动脉粥样硬化风险的临床分析

目的 评估脑梗死患者合并阻塞性睡眠呼吸暂停(OSA)时脑动脉粥样硬化的风险.方法 选择经TOAST分型为大动脉粥样硬化性脑梗死患者进行头颅磁共振血管成像(MRA)及颈动脉彩色超声检查了解颅内外动脉病变的情况,并根据检查结果分为无狭窄、狭窄程度＜50％、狭窄程度≥50％组.所有患者均行多导睡眠图检查(PSG),根据睡眠呼吸暂停低通气指数(AHI)分为正常组:AHI＜5次/h;轻度OSA:5 ～ 15 次/h;中度OSA:15 ～30次/h;重度OSA:AHI≥30 次/h.比较OSA与非OSA患者脑动脉狭窄的程度、数量和狭窄分布的区别.结果 75.0％ (57/76)的患者合并OSA,其中轻度OSA为32例(56.1％),中重度OSA为25例(43.9％),颅内动脉狭窄为80.7％ (46/57),颅外动脉狭窄为54.9％ (28/51);非OSA组19例,颅内、外动脉狭窄为总发生率分别为21.1％(4/19),20.0％ (3/15).分层研究表明,随着AHI的增加,颅内外动脉狭窄的程度增加,分布更广.在轻度OSA组,颅内动脉狭窄≥50％的为28.1％(9/32),多支狭窄为28.1％(9/32),颈动脉硬化为40.7％ (11/27)而在中重度OSA组,颅内动脉狭窄≥50％的为72.0％(18/25),多支狭窄为60％ (15/25),颈动脉硬化为70.8％(17/24).轻、中重度组间差异显著(P＜0.05).前、后循环脑动脉狭窄的分布无明显差异(P=0.588).结论 OSA增加脑动脉粥样硬化风险,OSA程度越重,脑动脉硬化的程度越重,分布越广.应重视对脑梗死患者睡眠呼吸功能的评估和干预.     

阻塞性睡眠呼吸暂停患者残余嗜睡与中枢性睡眠呼吸暂停事件的相关性

目的 探讨阻塞性睡眠呼吸暂停综合征(obstructive sleep apnea syndrome,OSAS)患者连续气道正压通气(continuous positive airway pressure,CPAP)治疗后残余嗜睡与中枢性睡眠呼吸暂停(central sleep apnea,CSA)事件的相关性以及匹配伺服通气(adaptive Bervo-ventilation,ASV)对CSA相关残余嗜睡的影响. 方法 选择正规使用CPAP治疗且排除其他嗜睡相关疾病的中、重度OSAS患者50例,分为残余嗜睡组(26例)和无残余嗜睡的对照组(24例).2组患者均先后接受自动CPAP治疗1个月和ASV治疗1周.分别比较2组患者治疗前、自动CPAP治疗时及ASV治疗时睡眠期的中枢性睡眠呼吸暂停指数(central sleep apnea index,CSAI),微觉醒指数(micro-arousal index,MAI)等多导睡眠监测参数及白天Epworth嗜睡评分(ESS),采用酶联免疫吸附试验测定肿瘤坏死因子a(tumor necrosis factor-a,TNF-a).两组间比较采用t检验,组内比较使用单因素方差分析,组内3个阶段两两比较采用q检验,两变量相关分析采用Pearson相关检验. 结果 治疗前2组呼吸暂停低通气指数(apnea hypoapnea index,AHI)、MAI、最低SpO2、ESS评分及血浆TNF-a水平组间比较差异没有统计学意义(t值分别为0.630、1.223、0.691、0.764和0.192,均P>0.05),但残余嗜睡组患者的CSAJ(14.39±4.21)次/h显著高于对照组[(8.58±5.75)次/h,t=4.097,P＜0.05].自动CPAP治疗1个月时2组的AHI、CSM、MAI和ESS评分均明显低于治疗前(g值为0.87～112.55,均P.＜0.05),但残余嗜睡组CSAI、MAI及ESS评分明显高于对照组[CSM:(7.19±1.75)次/h,(3.37±1.04)次/h,t=9.473,P＜O.05;MAI:(9.00±1.95)次/h,(2.36 4-0.66)次/h,f=14.385,P＜0.05;ESS:(9.54 4-0.51)分,(5.42±1.32)分,t=2.857,P＜0.05].ASV治疗时残余嗜睡组与对照组的CSAI、MAI及白天ESS评分均进一步下降,尤以残余嗜睡组的下降更为明显.此外残余嗜睡组内血浆TNF-a水平与治疗前(17.2±3.3)残余嗜睡,μg/L相比,自动CPAP治疗时(16.5 4-3.6)μg/L无明显下降(q值为11.696,P>0.05),但在ASV治疗时(12.6±3.4)μg/L与治疗前相比显著降低(q值为11.696,P＜0.05).血浆TNF-a水平与ESS评分呈显著正线性相关(r=0.503,P＜0.01),与MAI亦呈显著正相关(r=0.545,P＜0.01). 结论 经自动CPAP治疗后OSAS患者的残余嗜睡与治疗前、中存在的CSA事件频率有关.ASV在显著降低CSAI的同时也明显改善了提示ASV可有效治疗OSAS患者的残余嗜睡.TNF-a也与残余嗜睡患者的嗜睡程度相关,可能参与了残余嗜睡的发生.     

慢性心力衰竭患者合并睡眠呼吸紊乱的发生情况及胰岛素、内皮素水平变化

目的 观察慢性舒张性和收缩性心力衰竭患者睡眠呼吸紊乱(SDB)发生情况及胰岛素、内皮素变化.方法 对舒张性和收缩性心衰患者应用便携式睡眠监测仪进行睡眠监测,根据呼吸紊乱指数(AHI)将患者分为SDB组(AHI＞ 10次／h)和非SDB组(AHI≤10次／h),观察两组AHI与血氧饱和度(SaO2)(最低SaO2、SaO2＜ 90％占总记录时间百分比)和心率(最低心率、最高心率和最大心率变化)的关系及两组胰岛素、内皮素水平.结果 舒张性心衰90例患者有40例(44％)分为SDB组,均存在阻塞性睡眠呼吸暂停(OSA),其中有7例并存中枢性睡眠呼吸暂停(CSA);50例为非SDB组,两组AHI分别为(23.0±14.6)次／h和(5.1±2.4)次／h,SDB组最低SaO2更低、SaO2 ＜90％时间更长;AHI与SaO2＜ 90％的时间正相关,与最低SaO2负相关(均P＜0.05);SDB组和非SDB组发生严重心动过缓(心率≤40次／min)分别为80％ (32/40)和28％(14/50),SDB组最低心率更低,并与AHI负相关,最大心率变化与AHI正相关(均P＜0.05);20例SDB组与30例非SDB组空腹血糖无显著性差异(P＞0.05),SDB组餐后2h血糖、空腹及餐后2h血胰岛素浓度、内皮素浓度都高于非SDB组(P＜0.05).收缩性心衰54.5％患者(12/22)合并SDB,均为OSA,4例合并CSA并呈陈-施呼吸;SDB组和非SDB组AHI分别为(25.9±12.5)次／h和(5.8±2.5)次／h,SDB组最低SaO2更低,SaO2＜90％的时间更长;AHI与最低SaO2负相关,与SaO2 ＜90％的时间正相关;AHI与LVEF负相关(均P＜0.05).结论 慢性舒张性、收缩性心力衰竭合并SDB的患病率很高,且伴发严重夜间低氧血症,可致患者夜间出现严重心动过缓、内皮功能损害、胰岛素抵抗.     

子痫时可溶性血管内皮生长因子受体1的变化

目的 研究可溶性血管内皮生长因子受体1(sVEGFR-1)和血管内皮生长因子(VEGF)在子痫前期及子痫患者血清中的浓度变化,探讨sVEGFR-1和VEGF在妊娠期高血压(子痫前期及子痫)中的作用.方法 采用酶联免疫吸附试验(ELISA)分别测定轻度子痫前期(n=9)、重度子痫前期(n=10)及子痫(n=5)患者(子痫组,总共n=24)与正常妊娠妇女(对照组,n=18)外周血清中sVEGFR-1和VEGF的浓度.结果 (1)子痫组各组外周血清中sVEGFR-1水平[子痫前期轻度:(58±7)mg/L、子痫前期重度:(82±15)mg/L、子痫:(96±13)mg/L]明显高于对照组[(11±3)mg/L,P＜0.01],子痫前期重度和子痫组高于子痫前期轻度组(P＜0.05);(2)子痫组各组外周血血清中VEGF水平[子痫前期轻度:(0.37±0.04)mg/L、子痫前期重度:(0.24±0.04)mg/L、子痫:(0.16±0.01)mg/L]明显低于对照组[(0.43±0.04)mg/L,P(0.05～0.01],子痫前期重度和子痫组低于子痫前期轻度组(P＜0.05～0.01);(3)正常妊娠妇女外周血血清中sVEGFR-1水平与妊娠周数成正相关(r=0.508,P＜0.05),子痫前期及子痫组血清中sVEGFR-1水平与妊娠周数无关.结论 外周血中升高的sVEGFR-1和降低的VEGF可能与妊娠期高血压(子痫前期及子痫)的发病有关,并参与了子痫前期及子痫的病理生理过程.     

持续气道正压通气对重度阻塞性睡眠呼吸暂停低通气综合征合并高血压患者血压及血清瘦素水平的影响研究

目的探讨持续气道正压通气(CPAP)对重度阻塞性睡眠呼吸暂停低通气综合征(OSAHS)合并高血压患者血压及血清瘦素水平的影响。方法选取我院2011年3月—2014年3月收治的资料完整的重度OSAHS合并高血压患者98例,采用随机数字表法分为对照组40例和治疗组58例。对照组患者给予常规降压药物治疗,治疗组患者在常规降压药物治疗基础上给予CPAP。观察两组患者治疗前、治疗6个月后夜间收缩压、夜间舒张压、24 h平均收缩压、24 h平均舒张压、呼吸暂停低通气指数(AHI)、最低动脉血氧饱和度(SaO2)、最长呼吸暂停时间、血清瘦素水平。结果组间比较:两组患者治疗前夜间收缩压、夜间舒张压、24 h平均收缩压、24 h平均舒张压、AHI、最低SaO2、最长呼吸暂停时间及血清瘦素水平比较,差异均无统计学意义(P0.05);治疗组患者治疗后夜间收缩压、夜间舒张压、24 h平均收缩压、24 h平均舒张压、AHI及血清瘦素水平低于对照组,最低SaO2高于对照组,最长呼吸暂停时间短于对照组(P0.05)。组内比较:对照组患者治疗后24 h平均收缩压、24 h平均舒张压较治疗前降低(P0.05),而治疗前后夜间收缩压、夜间舒张压、AHI、最低SaO2、最长呼吸暂停时间及血清瘦素水平比较,差异均无统计学意义(P0.05);治疗组患者治疗后夜间收缩压、夜间舒张压、24 h平均收缩压、24 h平均舒张压、AHI及血清瘦素水平均较治疗前降低,最低SaO2较治疗前升高,最长呼吸暂停时间较治疗前缩短(P0.05)。直线相关分析结果显示,重度OSAHS合并高血压患者治疗后24 h平均收缩压与AHI呈正相关(r=0.587,P0.05),与最低SaO2呈负相关(r=-0.519,P0.05),与血清瘦素水平呈正相关(r=0.497,P0.05)。结论在常规降压药物治疗基础上联合CAPA治疗可有效减少重度OSAHS合并高血压患者夜间间歇性低氧血症,降低交感神经兴奋性及血清瘦素水平,进而使其血压降低,有利于更好地控制血压。     

持续气道正压通气对老年睡眠呼吸暂停患者神经损伤因子的影响

目的探讨不同时程持续气道正压通气(CPAP)对老年重度阻塞性睡眠呼吸暂停低通气综合征(OSAHS)患者血清S100β蛋白及神经元特异性烯醇化酶(NSE)的影响及意义。方法选择经多导睡眠仪(PSG)检查确诊的老年重度OSAHS患者为病例组,选取同期老年健康体检者90例为对照组。病例组给予CPAP治疗,治疗前及治疗后3、6个月采用PSG测最低血氧饱和度(LSaO_2)、平均血氧饱和度(MSaO_2)及呼吸暂停低通气指数(AHI),采用ELISA检测血清S100β蛋白和NSE水平。结果与治疗前比较,病例组治疗3、6个月较治疗前LSaO_2[(92.69±-2.12)%和(93.42±3.36)%vs(62.43±6.56)%]、MSaO_2[(94.43±4.65)%和(95.36±3.94)%vs(78.98±4.72)%]明显升高,AHI明显降低(P<0.05),病例组治疗前、治疗3、6个月血清S100β蛋白和NSE水平均显著高于对照组(P<0.05),病例组治疗6个月血清S100β蛋白[(0.56±0.12)μg/Lvs(0.98±0.11)μg/L]、NSE[(10.21±1.42)μg/Lvs(16.13±2.42)μg/L,P<0.05]均低于治疗3个月。结论 CPAP治疗能降低老年重度OSAHS患者神经系统的损害,其疗效与治疗时程有关,且可通过监测血清S100β蛋白及NSE水平的变化进行评估。     

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.     

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.     

Serological survey of HIV and syphilis in pregnant women in Madagascar

Objectives Peripartal transmission of human immunodeficiency virus (HIV) and Treponema pallidum, the causative agent of syphilis, leads to severe consequences for newborns. Preventive measures require awareness of the maternal infection. Although HIV and syphilis testing in Madagascar could be theoretically carried out within the framework of the national pregnancy follow‐up scheme, the required test kits are rarely available at peripheral health centres. In this study, we screened blood samples of pregnant Madagascan women for HIV and syphilis seroprevalence to estimate the demand for systemic screening in pregnancy. Methods Retrospective anonymous serological analysis for HIV and syphilis was performed in plasma samples from 1232 pregnant women that were taken between May and July 2010 in Ambositra, Ifanadiana, Manakara, Mananjary, Moramanga and Tsiroanomandidy (Madagascar) during pregnancy follow‐up. Screening was based on Treponema pallidum haemagglutination tests for syphilis and rapid tests for HIV, with confirmation of positive screening results on line assays. Results Out of 1232 pregnant women, none were seropositive for HIV and 37 (3%) were seropositive for Treponema pallidum. Conclusions Our findings are in line with previous studies that describe considerable syphilis prevalence in the rural Madagascan population. The results suggest a need for screening to prevent peripartal Treponema pallidum transmission, while HIV is still rare. If they are known, Treponema pallidum infections can be easily, safely and inexpensively treated even in pregnancy to reduce the risk of transmission.     

Variabilité des concentrations plasmatiques de l’angiotensinogène et risque d’hypertension artérielle chez le rat transgénique

Aim

Genetic polymorphisms of the human angiotensinogen gene are frequent and may induce up to 30% increase of plasma angiotensinogen concentrations with a blood pressure increase of up to 5 mmHg. Their role for the pathogenesis of human arterial hypertension remains unclear. High plasma angiotensinogen levels could increase the sensitivity to other blood pressure stressors.

Methods

Male transgenic rats with a 9-fold increase of plasma angiotensinogen concentrations and male non-transgenic rats aged 10 weeks were treated or not with NG-Nitro-L-arginine-methyl ester for 3 weeks in their drinking water (n = 3/group). Systolic blood pressure and body weight were measured at baseline and at the end of the study when left ventricular weight and ventricular expression of angiotensin I-converting enzyme and procollagen Iα1 were determined (polymerase chain reaction).

Results

At baseline, transgenic rats had +18 mmHg higher bood pressure and –8% lower body weight compared to non-transgenic rats (P < 0.05) without significant changes for the vehicle groups throughout the study (P > 0.05). NG-Nitro-L-arginine-methyl ester increased blood pressure, left ventricular weight and left ventricular weight indexed for body weight by +41%, +17.6% and +18.6% (P < 0.05) in transgenic and +25%, +5.3% and +6.7% (P > 0.05) in non-transgenic rats compared to untreated animals, respectively. Cardiac gene expression showed no differences between groups (P > 0.05).

Conclusion

Increased plasma angiotensinogen levels may sensitize to additional blood pressure stressors. Our preliminary results point towards an independent role of angiotensinogen in the pathogenesis of human hypertension and associated end-organ damage.     

Morphological and immunocytochemical heterogeneity of cultured pinealocytes from one-week-and two-month-old rats: Planimetric and densitometric investigations

Abstract: In vitro preparations of rat pinealocytes are widely used for biochemical analyses of signal transduction processes. This paper deals with morphological and immunocytochemical features of such preparations. Special attention was paid to the problems of whether pinealocytes represent a heterogeneous cell population and how such heterogeneity may develop during ontogeny. The investigations were performed with cells which were obtained from the pineal organ of one-week-and two-month-old rats, attached to synthetic peptide-coated coverslips or tissue culture chamber slides, and maintained under in vitro conditions overnight. The attached cells were then fixed with paraformaldehyde. These preparations yielded monolayers of spherical cells of different sizes; most cells were isolated, but some of them were aggregated and formed small clusters. On the average, the cells from the one-week-old animals were smaller than the cells from the two-month-old animals. Immunocytochemical demonstration of S-antigen, a pinealocyte-specific marker, showed that the majority of the cells from two-month-old animals were intensely or moderately labelled. Pinealocytes from one-week-old animals were less S-antigen immunoreactive. Only very few cells (less than 1% displayed glial fibrillary acidic protein (GFAP)-immunoreactivity. Planimetric investigations of the cell size and semiquantitative densitometric investigations of the intensity of the S-antigen immunoreaction revealed that (i) pinealocytes kept in vitro form a heterogeneous cell population, and that (ii) this heterogeneity increases during postnatal development from one-week-old to two-month-old animals. Two groups of pinealocytes can be distinguished based on their developmental fate: pinealocytes of one group grow dramatically, but show only a moderate increase in S-antigen immunoreactivity, and pinealocytes of the other group retain their size, but display a distinct increment in S-antigen immunoreacti vitv.     

Effects of pinealectomy and melatonin administration on certain indices of ovarian hyperplasia and/or hypertrophy in rats with both ovaries intact or after unilateral ovariectomy

Abstract: In earlier studies from other laboratories it was shown that melatonin decreased ovarian weight in rats and inhibited compensatory hypertrophy of the remaining ovary after unilateral ovariectomy. This study was designed to examine the influence of melatonin on certain indices of ovarian hyperplasia and/or hypertrophy in adult female rats with both ovaries preserved and with either an intact pineal gland or with the pineal gland removed (pinealectomy, PX) or, finally, in sham-PX animals. Similar studies were conducted on rats after unilateral ovariectomy, referring the examined parameters to the remaining intact ovary. The studies included mitotic activity of granulosa layer cells and corpus luteum cells, ovarian weight, ovarian cross-sectional area, cross-sectional area of the granulosa layer of all the Graafian follicles and the cross-sectional areas of the corpora lutea, visible on the ovarian cross-section. On the basis of results, we conclude that: 1) the effect of PX on the processes of ovarian hyperplasia and hypertrophy may vary; analogously, exogenous melatonin administration may influence ovarian hyperplasia and hypertrophy in different ways; 2) PX and exogenous melatonin may, under certain conditions, exert similar biological effects, even synergistic effects; 3) melatonin inhibits ovarian growth processes, while the effects of PX are variable; 4) the results indicate that in experiments performed on rats, with the use of two control groups, i.e., intact and sham-PX, melatonin effects on these two groups may differ.