胰岛淀粉样多肽在豚鼠胰腺分布的免疫组织化学研究

本文用免疫组织化学ＡＢＣ法,研究了胰岛淀粉样多肽（Ｉｓｌｅｔａｍｙｌｏｉｄｐｏｌｙｐｅｐｔｉｄｅ,ＩＡＰＰ或称Ａｍｙｌｉｎ）在豚鼠胰脏的分布,并用邻片免疫组织化学双标记法,观察了ＩＡＰＰ与胰岛素（Ｉｎｓｕｌｉｎ,ＩＮＳ）、生长抑素（ＳｏｍａｔｏｓｔａｔｉｎＳＳ）的共存关系。结果显示,豚鼠胰岛内绝大多数细胞都呈ＩＡＰＰ阳性免疫反应,在胰外分泌部的腺泡和导管内也散在分布有ＩＡＰＰ免疫反应阳性细胞。多数ＩＡＰＰ免疫反应阳性的细胞都显示ＩＮＳ免疫反应阳性,胰岛内少数ＩＡＰＰ阳性细胞也呈ＳＳ免疫反应阳性。说明ＩＡＰＰ主要分布在豚鼠的胰岛内．但也少量存在于外分泌部。ＩＡＰＰ主要和ＩＮＳ共存于Ｂ细胞内。但也和ＳＳ共存于Ｄ细胞内,提示ＩＡＰＰ可能通过自分泌途径调节ＩＮＳ和ＳＳ的分泌。     

不同生理状态对大鼠右心耳肌细胞特殊颗粒的影响──形态学和计量学研究

本文通过电镜观察和立体计量学方法,研究迷走神经和肾上腺素对ＳＤ大鼠右心耳肌细胞特殊颗粒（ＳＧ）的影响。结果是迷走神经切除组ＳＧ的体密度（ＶＶ）、颗粒平均直径（Ｄ）明显小于对照组（Ｐ＜０．００１）,肾上腺素组ＳＧ的ＶＶ、Ｄ、数密度（Ｎｖ）也明显小于相应对照组（Ｐ＜０．００１）。结果提示迷走神经对心钠素的释放是抑制作用,肾上腺素对心钠素的释放是促进作用。本研究还为ＳＧ的产生与分型,心钠素的多种释放方式提供了形态学资料。     

糖尿病大鼠胰岛的一氧化氮合酶(NOS)与胰岛毛细血管三维结构的改变

以还原型辅酶Ⅱ黄递酶（ＮＡＤＰＨｄ）组织化学方法及扫描电镜（ＳＥＭ）,对正常组和糖尿病组大鼠胰岛的一氧化氮合酶（ＮＯＳ）与胰岛毛细血管的三维结构进行了观察。结果表现：正常组胰岛呈弥漫的蓝黑色ＮＯＳ阳性反应产物,但在糖尿病组胰岛的ＮＯＳ反应则明显减弱。ＳＥＭ显示正常组胰岛毛细血管蟠曲呈球状,且血管管径基本一致,而在糖尿病组胰岛中则可见部分毛细血管明显扩张。因此我们认为,糖尿病大鼠的胰岛毛细血管结构和功能均发生了改变。     

氧化修饰HDL刺激培养人主动脉平滑肌细胞增殖

平滑肌细胞（ｓｍｏｏｔｈ ｍｕｓｃｌｅ ｃｅｌｌ,ＳＭＣ）增殖在动脉粥样硬化（ａｔｈｅｒｏｓｃｌｅｒｏｓｉｓ,ＡＳ）形成中起着重要作用。氧化修饰ＨＤＬ（ｏｘｉｄｉｘｅｄ ＨＤＬ,ＯＸ－ＨＤＬ）可刺激＾３Ｈ－ＴｄＲ掺入培养人动脉ＳＭＣ的ＤＮＡ,促进ＳＭＣ增殖。以四甲工偶氮唑盐９ＭＴＴ）法直接观察ＯＸ－ＨＤＬ对培养人动脉ＳＭＣ增殖细胞数的影响。结果显示,天然ＨＤＬ（ｎａｔｉｖｅ ＨＤＬ Ｎ－ＨＤＬ）对     

大鼠生后发育过程中胃肠胰生长抑素基因的表达

本实验采用地高辛精标记ｃＲＮＡ探针原位杂交技术和ＡＢＣ免疫组织化学方法,研究了大鼠生后发育过程中胃肠胰组织生长抑素（ＳＳ）基因的表达。结果显示,大鼠生后发育过程中,胃腺ＳＳ杂交阳性细胞及ＳＳ－ＩＲ细胞的密度（细胞数／ｍｍ粘膜肌长）均随天龄增长而增大,至第１５天前后达高峰,随后开始下降,至成年时,与出生时水平接近;十二指肠则在生后初期细胞密度较高,５天以后开始降低,第２０天后降至成年水平。胰腺的ＳＳ杂交阳性细胞及ＳＳ－ＩＲ细胞密度（细胞数／ｍｍ２）变化规律与胃腺相似,随天龄增大,至第１０天前后达高峰,第２０天左右降至成年水平,与出生水平接近。研究结果表明,胃肠胰组织ＳＳ基因表达与胃肠胰的生长发育具有一定的相关性。     

NIDDM发病前后中国地鼠胰岛和肝脏细胞GLUT的变化研究

用胶原酶法分离胰岛细胞、超速离心法提取中国地鼠胰岛和肝脏细胞膜蛋白,ＳＤＳ电泳、ＷｅｓｔｅｒｎＢｌｏｔｔｉｎｇ分离ＧＬＵＴ后,应用ＧＬＵＴ２抗体免疫结合法测定ＧＬＵＴ的含量与分子量,同时测定了动物血糖、尿糖和血浆胰岛素的含量、显微镜下直接计数了胰岛细胞总数。结果表明：ＮＩＤＤＭ发病后,自发ＮＩＤＤＭ中国地鼠胰岛细胞ＧＬＵＴ含量减少,与ＧＬＵＴ２抗体反应明显减弱,但肝脏ＧＬＵＴ无明显变化。胰岛细胞总数发病前后大体一致。而血糖、尿精及血浆胰岛素浓度明显升高。     

百日咳毒素单克隆抗体在抗感染中的应用

百日咳毒素（ＰＴ）单克隆抗体（ＰＴ－ＭｃＡｂ）具有特异性中和体外和体内百日咳毒素的促进白细胞增多（ＬＰ）、组胺敏感（ＨＳ）、胰岛激活（ＩＡ）、腺苷三磷酸核糖基转移酶（ＡＤＰ－Ｒ）、ＣＨＯ细胞簇聚等多种生物学活性的特性,同时亦具有防御百日咳杆菌脑内和气溶胶攻击的保护作用。     

光周期对光敏核不育水稻叶绿体类囊体膜超分子结构的影响

通过冰冻撕裂叶绿体类囊体膜电镜术的研究,在超分子水平上揭示出长日照（ＬＤ）与短日照（ＳＤ）对突变型光敏核雄性不育水稻农垦５８Ｓ及其野生型农垦５８ 倒二叶叶绿体类囊体膜的形成有不同的影响。农垦５８－ＳＤ 和农垦５８－ＬＤ差别不明显;而农垦５８Ｓ－ＳＤ和农垦５８Ｓ－ＬＤ之间出现较明显的差异：（１）农垦５８Ｓ－ＳＤ 叶绿体类囊体膜的垛叠和非垛叠膜区的４ 个冰冻撕裂膜小面呈现的功能蛋白粒的密度、大小及构象分布与其对照农垦５８－ＳＤ 和农垦５８－ＬＤ 类似,均属正常的超分子结构类型。（２）农垦５８Ｓ－ＳＤ叶绿体垛叠类囊体膜区的外质撕裂面（ＥＦｓ）功能蛋白粒的密度比５８Ｓ－ＬＤ的大,且在有的垛叠膜区呈现出类晶格状的规则排列。（３）农垦５８Ｓ－ＬＤ 叶绿体非垛叠膜区的原生质撕裂面（ＰＦｕ）和外质撕裂面（ＥＦｕ）出现频率较低,往往在基粒的边缘膜或末端中能找到,且分布于膜上的功能蛋白粒的密度较小。有的叶绿体ＥＦｕ、ＰＦｕ、ＥＦｓ和垛叠膜区原生质撕裂面（ＰＦｓ）功能蛋白粒极少或丧失,表明类囊体膜受到严重损伤     

大肠癌及癌旁粘膜中胃泌素、生长抑素细胞的免疫细胞化学研究

本文对１７例大肠癌病人癌组织及癌旁粘膜中的胃泌素细胞和ＳＳ细胞进行免疫细胞化学观察（ＰＡＰ）。结果显示：在癌及癌旁粘膜中来见胃泌素细胞;癌细胞中均未见ＳＳ细胞;癌旁粘膜中ＳＳ细胞的形态、位置近于正常。距癌灶０～２ｃｍ粘膜ＳＳ细胞数和总阳性强度显著高于２～６ｃｍ和４～６ｃｍ粘膜（Ｐ＜０．０１）。０～２ｃｍ粘膜中ＳＳ细胞数和总阳性强度与粘膜上皮细胞异型增生程度呈显著负相关（前者Ｐ＜０．０１;后者Ｐ＜０．０５）。Ｄｕｋｅｓ’ＣＤ期者０～２ｃｍ和２～４ｃｍ粘膜中细胞平均阳性强度均显著低于ＡＢ期患者（前者Ｐ＜０．０５,后者Ｐ＜０．０１）。距癌０～２ｃｍ粘膜ＳＳ细胞增多和总阳性强度增高可能是机体发生在病变部位的胃肠内分泌防御反应的细胞学基础,并受到粘膜上皮异型增生程度的影响。晚期０～４ｃｍ粘膜ＳＳ细胞分泌ＳＳ减少是机体胃肠内分泌功能衰退的表现。     

新生大鼠窦房结组织、培养细胞的glycogen,LDH和SDH定量形态学研究

本实验采用窦房结细胞纯化培养、ＰＡＳ、Ｐｅａｒｓｏｎ和Ｐｒｅｓｔｏｎ反应以及图像分析等方法,研究了新生ＳＤ大鼠窦房结细胞的糖原（ｇｌｙｃｏｇｅｎ）、琥珀酸脱氢酶（ＳＤＨ）,和乳酸脱氢酶（ＬＤＨ）的分布和含量。结果显示,在窦房结组织中的糖原（／）与心房中（／）、心室中（）含量近似;ＳＤＨ含量和活性（＋／）与心房中（＋／）几乎相等,但明显低于心室中（／）;ＬＤＨ的含量和活性（／）比心房中（／＋）的稍高,但明显高于心室中（＋／－）。图像分析结果是：培养窦房结细胞ＳＤＨ含量和活性显著低于心室肌细胞中的ＳＤＨ（Ｐ＜０．０１）,而ＬＤＨ含量和活性显著高于心室肌细胞中的ＬＤＨ（Ｐ＜０．０１）。本文还对ＳＤＨ、ＬＤＨ在窦房结的分布及生理作用进行了讨论。     

Lactose synthetase activities in rat and mouse mammary glands

The activities of lactose synthetase (in the presence and absence of α-lactalbumin), galactosyltransferase and α-lactalbumin levels were determined in rat and mouse mammary glands during pregnancy, lactation and involution. In the rat, essentially none of the above activities were detected prior to parturition. This was followed by a sharp increase with the maximum occurring during late lactation and then by a rapid drop during involution. In the mouse, detectable levels of all the activities occurred at 15 days of pregnancy and these levels increased during pregnancy and reached a maximum level during early lactation and again sharp decreases occurred during involution. The study shows that mammary gland development occurs at an earlier date in the mouse than in the rat.     

Differential recruitment of T- and IgA B-lymphocytes in the developing mammary gland in relation to homing receptors and vascular addressins.

The mammary gland (MG) develops new vasculature and is colonized by lymphocytes, primarily T-cells, during pregnancy. In contrast, during lactation it is colonized primarily by IgA-containing B-cells (c-IgA cells). To explain this difference, we analyzed the spatiotemporal relationships between lymphocytes that expressed peripheral or mucosal homing receptors (HR) and the location of their vascular counterreceptors using quantitative immunohistochemical techniques. We observed that the density of beta(7+)/CD3(+) T-cells varied with the amount of the mucosal addressin cell adhesion molecule-1 (MAdCAM-1)-stained area. Both increased during pregnancy to peak at delivery, decreased rapidly in early lactation to a steady level in mid- and late lactation, and returned to resting values after weaning. Although 60% of these beta(7+)/CD3(+) T-cells scattered in the epithelium co-expressed alpha(E)beta(7), whereas the remaining 40% in association with blood vessels were alpha(4)beta(7), these results are consistent with a role of MAdCAM-1 in the localization of alpha(4)beta(7+) T-cells. In contrast to T-cells, beta(7+)/c-IgA(+) B plasmablasts (approximately 30% of total c-IgA cells) were located at the alveolar confluence, and their numbers increased in mid- and late lactation when MAdCAM-1 density plateaued. However, both T-and B-cells decreased after weaning. These results show an association between MAdCAM-1 expression level and recruitment of T-cells that does not hold for c-IgA B cells. Furthermore, the recruitment and accumulation of alpha(4)beta(7+) c-IgA cells are reminiscent of locally produced chemoattractants. (J Histochem Cytochem 47:1581-1592, 1999)     

Calmodulin content of rat mammary tissue and isolated cells during pregnancy and lactation.

The calmodulin content of heat-treated extracts of rat mammary tissue and isolated cells was measured by using stimulation of cyclic nucleotide phosphodiesterase (PDE) activity and radioimmunoassay (r.i.a.) procedures. The calmodulin content of mammary tissue increased 2.5-fold near the time of parturition, remained at the elevated level during lactation, then, after the onset of involution, decreased to values similar to those measured from mammary tissue of pregnant rats. When tissue from 15 animals in different stages of pregnancy, lactation and involution were compared, the r.i.a. gave 2.6-fold higher results than the PDE assay. To investigate further the increase in calmodulin content of mammary tissue, secretory and myoepithelial cells were enzymically dissociated from rat mammary tissue during different stages of pregnancy, lactation and involution. Protein, DNA, lactose, glucose-6-phosphate dehydrogenase and alkaline phosphatase were assayed to characterize the cell fractions. By using r.i.a., the calmodulin content per mg of protein in isolated secretory-cell fractions was high near parturition, then decreased and remained relatively constant during lactation. The amount of calmodulin expressed per mg of DNA in secretory cells did not show a marked change near parturition, suggesting a constant amount of calmodulin per cell. The calmodulin content of myoepithelial cells dissociated from mammary tissue and measured by using r.i.a. was 6-fold lower than in secretory cells and remained relatively constant during the course of lactation. The changing levels of calmodulin in rat mammary tissue during development are suggested to be related to proliferation and destruction of secretory epithelial cells, events that occur near parturition and involution respectively.     

Protective effect of folic acid against oxidative stress produced in 21-day postpartum rats by maternal-ethanol chronic consumption during pregnancy and lactation period

In this paper we show the protective effect of folic acid on oxidative stress in offspring caused by chronic maternal ethanol consumption during pregnancy and the lactation period. Glutathione reductase (GR) specific activity was assayed in liver and pancreas of offspring and mothers. In the offspring, these tissues were also assayed for markers of oxidative damage to lipids and proteins. The results show that ethanol exposure during pregnancy and lactation increased the specific activity of GR in tissues of the mothers (32-34% increase) as well as in the liver of their progeny (24%). Thiobarbituric acid reactive substances (TBARS) were also increased in the liver and pancreas of 21-day-old rats (37- and 54%, respectively). Alcohol also increased the amount of carbonyl groups in proteins in both tissues. These measures of ethanol-mediated oxidative stress were mitigated when pregnant rats were treated with folic acid concomitantly to ethanol administration. The antioxidant capacity of folic acid seems to be involved in its protective effect. The results obtained in the present work suggest that folic acid may be useful in the prevention of damage and promotion of health of the progeny of ethanol-treated rats.     

Enzymic changes in rabbit and rat mammary gland during the lactation cycle

1. Activities of glucose 6-phosphate dehydrogenase (EC 1.1.1.49), 6-phosphogluconate dehydrogenase (EC 1.1.1.44), isocitrate dehydrogenase (EC 1.1.1.42), malate dehydrogenase (EC 1.1.1.37), malate dehydrogenase (decarboxylating) (EC 1.1.1.40), and pyruvate carboxylase (EC 6.4.1.1) were determined in subcellular fractions of mammary gland from rabbits during pregnancy, at different stages of lactation and during weaning. The results were compared with those obtained in similar experiments with rat mammary gland. 2. Three bases of expression of the activity of enzymes in the particle-free supernatant fraction of mammary gland were compared. During lactation, activity expressed per mg. of particle-free supernatant protein (uncorrected for milk protein) correlated well with that expressed per mug. of DNA phosphorus. The disadvantages of expressing activities per g. wet wt. are discussed. 3. The major differences between the two tissues were: (a) neither malate dehydrogenase (decarboxylating) nor a soluble form of pyruvate carboxylase could be detected in rabbit mammary gland at any stage of the lactation cycle; (b) isocitrate dehydrogenase increased in activity during lactation in rabbit mammary gland, but not in that of the rat. 4. Pyruvate carboxylase in the mitochondrial fraction of rabbit mammary gland, and in both the mitochondrial and the soluble fractions of rat mammary gland, did not change in activity during lactation. 5. For each tissue, the NADP-dependent dehydrogenases studied had a high activity at all stages of the lactation cycle compared with the rate of fatty acid synthesis at mid-lactation. The significance of these results is discussed with respect to the supply of NADPH via NADH.     

Detection of relaxin by immunohistochemistry in the corpus luteum during lactation

The occurrence of relaxin in corpora lutea (CL) throughout lactation was studied in rats and pigs using the avidin-biotin immunoperoxidase procedure and homologous antisera to purified relaxins. In the rat, both CL from the previous pregnancy (CLp) and CL formed after postpartum ovulation, termed CL of lactation (CLL), were studied. In the rat, relaxin was localized only in cells of the CLp in early lactation, and immunostaining declined with advancing lactation. In late lactation (Days 16-20), immunoreactive relaxin first appeared in cells of the CLL, although the intensity was less relative to that observed in the CLp in early lactation. Cells of the CLp were sensitive to the effects of exogenous prostaglandins (PG) as shown by a loss of relaxin immunostaining at both 12 and 48 h after a PGF2 alpha challenge. In the sow, the CLp showed highest immunostaining in early lactation with a gradual reduction as lactation progressed, such that by Day 20 lactation, immunostaining was lost. These localization studies show that immunoreactive relaxin is present in the CL during lactation. Low levels of relaxin localized in the CLL of late lactation in the rat probably represents newly formed hormone, whereas the immunostaining in the CLp of the pig and rat appears to be residual relaxin and an indicator of the degeneration of the CLp with advancing lactation.     

Comparative profiles of the hexose monophosphate dehydrogenases in rat tissues over the lactation cycle

The mammary gland tissue hexose monophosphate dehydrogenase activities were low in virgin, pregnant and weaned rats, but increased at the onset of lactation. The muscle and liver glucose 6-phosphate dehydrogenase activity peaked at early and late lactation respectively. The liver 6-phosphogluconate dehydrogenase peaked in late pregnancy and remained elevated through lactation. The muscle 6-phosphogluconate dehydrogenase peaked at the onset of lactation. The adipose tissue hexose monophosphate dehydrogenases exhibited small changes during pregnancy and lactation. The spleen hexose monophosphate dehydrogenases did not respond to lactation An overshoot in both the liver and the adipose tissue hexose monophosphate dehydrogenases was observed on weaning. Serum glucose levels remained unchanged throughout pregnancy, lactation and weaning. Only liver glucose 6-phosphate dehydrogenase activity correlated with plasma insulin, which also correlated positively with food consumption. The results demonstrate that tissue-specific control of the hexose monophosphate dehydrogenases occurs in the female rat during its complete lactation cycle.     

Regulation of 6-phosphofructo-1-kinase from the epithelial cells of rat small intestine during pregnancy and lactation

The regulation of 6-phosphofructo-1-kinase (PFK) in the epithelial cells of rat small intestine was studied during pregnancy and lactation. The total activities and activity ratios (activity at 0.5 mM fructose 6-phosphate at pH 7.0/activity at pH 8.0 (nu 0.5/V] of the partially purified mucosal PFK were found to increase initially in early pregnant rats (11-12 days of gestation) and to fall back to normal in late pregnant rats (19-20 days of gestation). These changes in enzyme activity during pregnancy were associated with similar changes in the circulating levels of progesterone. The maximal activity and activity ratio (nu 0.5/V) were increased in male and female rats injected with progesterone. An increase in the total activity and activity ratio of mucosal PFK was also obtained in lactating rats. However, the enzyme was not strongly activated by inorganic phosphate, fructose 2,6-bisphosphate or glucose 1,6-bisphosphate either in early pregnant or lactating rats. These results indicate that mucosal PFK is already present as an active form during early pregnancy and lactation. Therefore, it is suggested that female sex hormones increase the circulating levels of insulin during early pregnancy which, in turn, positively affect the activity of mucosal PFK which could be also stimulated by the increased levels of fructose 2,6-bisphosphate. The increased activity of PFK in the peak lactating rats could be possible because of an increased demand for lactate production from glucose together with the stimulation of PFK by the increased concentrations of fructose 2,6-bisphosphate which therefore increases the rate of glycolysis.