去松果体对老年大鼠脑神经元脂褐素含量的影响

目的探讨摘除松果体对老年大鼠海马、斜角带神经元脂褐素含量的影响。方法摘除老年大鼠松果体后22天观察其海马CA1区、斜角带垂直支神经元脂褐素含量的变化。结果去松果体后大鼠斜角带垂直支神经元的脂褐素含量明显增多,海马CA1区神经元的脂褐素含量无明显变化。结论松果体对老年大鼠脑神经元具有一定的保护用。     

大鼠松果体衰老的形态学研究

目的 探讨松果体形态结构的衰老性变化,为进一步研究松果体与衰老的关系提供形态学基础。方法 随机选取3月龄和34月龄SD大鼠10只分别作为青年组和老年组,用光镜和电镜结合形态计量学分法分析松果体细胞和神经胶质细胞密度及其指数;松果体细胞线粒体的Vv、Sv、Nv,高尔基器的Vv、Sv、粗面内质网的Sv、溶酶体的Vv;松果体神经终末的Vv及其线粒体的Vv、Sv、Nv、小颗粒囊泡的NA。结果 与青年组相比,老年组松果体细胞核形状不规则,核膜皱褶增多和加深。细胞浆内粗面内质网减少,排列紊乱,分散,脱颗粒明显;线粒体结构不清、肿胀、嵴断裂、消失、空泡化等。老年组松果体细胞密度比青年组减少,而神经胶质细胞密度增加,差异有高度显著性(P<0.01)。老年组神经胶质细胞指数比青年组高(P<0.01)。老年线粒体Vv与青年组无差别,但老年组线粒体Sv、Nv均比青年组减少(P<0.01)。老年组高尔基器的Vv、Sv均比青年组减少(P<0.01);老年组粗面内质网Sv比青年组减少,而老年组溶酶体Vv比青年组增加(P<0.01);老年组神经终末Vv比青年组减少(P<0.01);老年组神经终末中小颗粒囊泡NA比青年组减少(P<0.01);老年组线粒体Sv、Nv比青年组减少(P<0.05),两组神经终末中线粒体Vv无差别(P>0.05)。结论 老年大鼠松果体已发生衰老性变化,这可能与机?     

衰老时人大脑皮质脂褐素体的超微结构研究

用电子显微镜对10例正常老年人和7例正常成年人脑额叶、顶叶和颞叶皮质神经元内脂褐素体进行对比研究并作定量分析.发现老年组脂褐素体结构复杂,空泡增多,出现异质性.统计学资料表明,老年组神经元内脂褐素体的沉积量明显高于正常成年组.     

摘除松果体对大鼠运动活动近似昼夜节律的影响

为了分析松果体及共褪黑激素在哺乳动物近日节律调探机制中的作用，本文对摘除松果体和眼球后的大鼠的运动活动，进行了连续６天的观测，并以单纯致盲的动物作对照。经用余弦节律分析法对实验数据进行处理，结果表明，戌对照组相比，去松果体的各动物运动活动昼夜节律的峰值相位较分散，节律振幅的算术平均值较小；对群体平均的节律特征值进行统计学检验，见去松果体动物群体平均的运动活动已怃明显的昼了律而对照动物的此节律仍然存     

老年大鼠松果体中褪黑素含量的测定

目的采用高效液相色谱法(HPLC)测定老年大鼠松果体中褪黑素(MT)含量。方法≥24月龄16只健康SD大鼠,雌雄各半,随机分为2组。采用HypersilODS2(5.0×200 mm)色谱柱,流动相为甲醇与水(3∶2);流速为1.0 ml/min,柱温为35℃,检测波长225 nm。结果松果体MT含量在50~1000 pg之间呈线性关系良好,MT的检测下限为10pg,回归方程为y=36.917X+838.36(r=0.9998,p<0.05)平均日内RSD=1.13%,时间RSD=1.71%。结论HPLC法测定大鼠松果体MT含量简便、快速、灵敏度高,准确度与精密度较好,是一种理想的检测方法。     

大鼠松果体褪黑素含量增龄性变化的研究

目的探讨大鼠松果体褪黑素含量的增龄性变化规律。方法32只健康SD大鼠随机分为1～2月龄组、4～5月龄组、11～12月龄组和≥24月龄组4个年龄组。每组8只,雌雄各半。用高效液相色谱测定松果体褪黑素含量。结果1～2月龄组褪黑素含量为1.492±0.158,4～5月龄组为1.088±0.059,11～12月龄组为0.233±0.101,≥24月龄组为0.127±0.037,各组间差异有统计学意义(P<0.01)。结论大鼠松果体随增龄而出现褪黑素含量下降,这可能是导致机体发生衰老的原因之一。     

大鼠松果体组织结构的增龄变化

目的；观察大鼠松果体组织结构的增龄变化。方法：应用计算机图像分析和透射电镜研究了幼年，青年和老年大鼠松果体。结果：随着年龄增加，大鼠松果体的体积依次增大，每个视野内松果体实质面积和实质细胞数减少，间质增生，衰退的松果体暗细胞在各年龄组大鼠松果体中均非常少见，实质细胞间存在与血管周隙和神经胶质细胞周隙相通的细胞间小管。结论：随着年龄增加，大鼠松果体的实质细胞总数和松果体细胞总数下降或衰退的暗细胞总灵敏增加，从而导致松果体分泌功能下降的观点，值得商榷，大鼠松果体分泌物可能通过细胞间小管-血管周隙和神经胶质细胞周隙-囊上皮孔而直接释放到蛛网膜下隙的脑脊液中，结缔组织增生可阻碍其释放。     

卵磷脂对皮肤角质层水分和脂褐素含量的影响

印解脂，即磷脂酸四＊（的问加班加班班回，ie，对皮肤结构变化的影内，国外学者做了大量的工作，我们采取皮肤外敷试验，对印所脂影响皮肤角质层水分合卫和角质细胞胎揭素含量进行了初步研究，结果表明，卵历腊对维持皮肤角质层水分含量的稳定和抑制角质细胞脂褐素的形成均有明显的效果。材料与方法（－）试验所用卵磷脂（lerlll’11’1）采用有机溶剂综合革取法提取精制。（二）选用120－150d‘体重2，3－2．8kg的健康白色家兔阳本大耳白）20只为实验动物，雌雄不限（水分和脂报素含量的测定各用10只），为避免个体间差异，对照和试验均在…     

大鼠松果体囊上皮表面的扫描电镜观察

目的 探讨松果体激素释放到蛛网膜下隙脑脊液途径的结构基础.方法 对1.5月龄和12月龄大鼠松果体浅部,进行松果体囊表面的扫描电镜观察.结果 在大鼠松果体囊表面发现存在筛状囊上皮孔和喇叭口状囊上皮孔.筛状囊上皮孔主要存在于1.5月龄大鼠的松果体囊上皮,是由许多密集排列的囊上皮细胞周边部细胞膜凹陷形成的圆形孔洞,筛孔直径200～500 nm;喇叭口状囊上皮孔见于1.5月龄和12月龄大鼠的松果体囊表面,由相邻上皮细胞向松果体内部凹陷,形成圆形或椭圆形开口,孔径1～4 μm.在两组动物的松果体囊表面,可见到直径800～1 000 nm的球形分泌颗粒样结构.结论 松果体分泌颗粒的释放形式,可能存在连同颗粒被膜的整体释放;松果体激素或分泌颗粒,可能会通过松果体囊上皮孔,直接进入蛛网膜下隙的脑脊液.     

Effect of photoperiod on the pineal melatonin rhythm in neonatal rats

Photoperiod already modulates pineal melatonin rhythm in neonatal rats. Pineal melatonin content was about 500 fmol during day and increased up to 2000 and 3000 fmol at night in 8- and 12-day-old rats, respectively. On long photoperiods (LD 14:10) melatonin was increased above 1000 fmol for about 8 h while on short photoperiods (LD 8:16) for 12 to 14 h. Melatonin pattern may thus transduce photoperiodic effects in neonatal rats. However, no differences in plasma LH were found in the rats kept on long and short photoperiods.     

The pineal gland and the development of salt intake patterns in male rats

The effect of gonadectomy, sham-gonadectomy, pinealectomy, and sham-pinealectomy on the concentration of NaCl in the total volume of fluid drunk per day ([NaCl]_I) in male rats offered a free choice between water and 3% saline was measured. Neonatal gonadectomy increased [NaCl]_I in adult males but had no effect on immature rats. If the rats, however, were neonatally pinealectomized as well as gonadectomized, the increase of [NaCl]_I also appeared in the immatures. Neonatal sham-pinealectomy decreased [NaCl]_I in immature and adult rats, both gonadectomized and sham-gonadectomized. In adult neonatally gonadectomized males the effects of sham-pinealectomy did not occur in those animals actually pinealectomized. The role of the pineal gland in the regulation of water and salt intake is discussed in relation to the function of hypothalamus, neonatal stress, and sexual maturation.     

Lymphopoiesis in the chicken pineal gland

Pineal lymphoid development was studied in two breeds of chickens from hatching until sexual maturity. No lymphocytes were found in the pineal prior to 9 days of age (da). Lymphocytes migrate through the endothelium of venules into the pineal stroma. Lymphoid tissue reached its maximal accumulation in 32-da pineal glands of both breeds. At this age, the New Hampshire (NH) breed had a larger proportion of lymphoid volume to total pineal volume (32%) than did pineal glands from White Leghorn (WL) chickens (18%). Averaged over the period 23 to 62 da, NH chickens (a heavy breed) had a lymphoid volume (0.753 mm³) that was about three times greater (P < 0.05) than that of the lighter WL breed (0.251 mm³). Lymphocytes are able to enter cerebrospinal fluid from lymphoid accumulations (LA) embedded in the choroid plexus by migrating between choroid ependymal cells. The 122-da chickens typically lacked lymphoid tissue in the pineal gland with the exception of occasional LA contained in capsular tissue. Surgical bursectomy, thymectomy, or their combination at hatching followed with whole-body irradiation (IR) at 24 hours postsurgery inhibited the initial influx of lymphocytes usually seen in 9-da pineal glands. Also, these treatments prevented formation of germinal centers normally found in the pineal at 3 and 5 weeks and reduced total pineal volume at each age examined. However, pineal lymphoid volume of the surgical-IR group did not differ from control-IR chickens at either 3 or 5 weeks. Pineal glands from birds made agammaglobulinemic (bursa-cell depleted) by cyclophosphamide treatment in ovo were devoid of germinal centers, although thin strands of lymphocytes were usually found along venous sinuses. These dissociation studies suggest that the normal expression of lymphoid tissue in the chicken pineal gland is dependent on the bursa and thymus. Furthermore, these observations indicate that the pineal gland should be considered a functional component of the chicken's lymphomyeloid complex.