凝集素样氧化低密度脂蛋白受体1在兔自体静脉移植物及其粥样硬化病变中的分布表达

目的自体静脉移植物粥样硬化的产生机制有其特殊性,我们研究了一种新的氧化低密度脂蛋白(OXLDL)的受体,即凝集素样氧化低密度脂蛋白受体1(LOX1)在兔自体静脉移植物及其粥样硬化病变中的表达,探讨其在静脉移植物粥样硬化形成中的作用。方法将30只新西兰大白兔随机分为正常对照组、单纯移植组和高脂移植组3组,分别给予普通饲料喂养(N=10)、单纯自体颈外静脉移植(N=10)和自体颈外静脉移植加高脂饲料喂养(N=10)。在实验12周末处死动物,静脉移植段行免疫组化染色检测LOX1的表达及分布,用半定量逆转录聚合酶链反应(RTPCR)检测LOX1MRNA表达的情况,并且统计分析血清总胆固醇水平、内膜厚度与LOX1的表达之间的关系。结果正常对照组的颈外静脉组织中仅见极少量LOX1表达于静脉内皮细胞表面;而单纯移植组的静脉移植物的新生内膜和内皮细胞层,可见LOX1的表达明显升高(0.31±0.14比0.09±0.04,P<0.01),其中LOX1表达最强的是内皮细胞;高脂移植组静脉移植物的内皮和粥样硬化部位,可见LOX1的表达更加显著上调(0.93±0.34比0.31±0.14,P<0.01),在粥样硬化部位,内皮细胞和泡沫细胞LOX1染色均阳性,而表达最强的也是内皮细胞。并且LOX1的表达和血清总胆固醇水平、内膜厚度均显著正相关(P=0.00和0.02),偏相关系数分别为0.78和0.42。结论LOX1表达于兔自体静脉移植物的内皮和新生内膜,表达量较正常静脉组织明显上调,高胆固醇血症可以上调静脉移植物粥样硬化部位LOX1的表达,提示LOX1可能参与了静脉移植物粥样硬化的发生发展。     

兔自体静脉移植物粥样硬化模型的建立

为研究自体静脉移植物粥样硬化的发病机制以进行干预研究，建立家兔动物模型。将30只雄性新西兰大白兔随机分为正常对照组(n=6)、单纯移植组(n=12)和高脂移植组(n=12)，分别给予普通饲料喂养、单纯自体颈外静脉移植加普通饲料喂养和自体颈外静脉移植加高脂饲料喂养。实验12周末处死动物，检测血脂水平，同时观察静脉移植段的形态特征。结果发现，高脂移植组出现明显的高脂血症，其颈静脉移植段出现较典型的粥样硬化病变。包括内皮细胞脱落、内膜增生、平滑肌细胞移行增殖、脂质沉积和泡沫细胞形成等；单纯移植组的颈静脉移植段仅有明显的内膜增生和平滑肌细胞表型转换及增殖，未见明显脂质沉积；而正常对照组及各移植组对侧颈外静脉未见明显异常。结果提示，自体颈外静脉移植结合高脂饲料喂养可成功建立兔自体静脉移植物粥样硬化模型，此模型可用于人自体静脉移植物粥样硬化发生机理及防治措施等的研究。     

SDF-1α在大鼠静脉移植物再狭窄中的作用

目的:观察基质细胞衍生因子（SDF）-1α在大鼠自体颈外静脉移植物新生内膜增厚中的作用。方法:将60只体质量在250~300 g的 SD雄性大鼠随机分为模型组和CXC趋化因子受体4拮抗剂（AMD3100）组［AMD3100 1mg/(kg·d)×7腹腔注射］,每组30只,建立大鼠自体颈外静脉端侧吻合到颈总动脉的移植物模型后,给予不同的干预。两组大鼠分别在术后0、3、7、14及28 d取静脉移植物,经HE染色后观察移植物新生内膜的厚度;用免疫荧光染色法检测SDF-1α的表达。结果:随着时间的延长,模型组移植物新生内膜的厚度逐渐增加（P<0.01）。与模型组相同时间点相比较,AMD3100组新生内膜的厚度减少（P<0.01）;免疫荧光染色法显示,SDF-1α在移植物中的表达增加,术后7 d表达达到高峰,术后28 d仍能检测到SDF-1α表达。结论:SDF-1α参与了静脉移植物新生内膜的增厚,AMD3100能减轻新生内膜的增厚。     

体外培养间充质干细胞移植对颈动脉损伤后局部NO含量和eNOS mRNA表达的影响

目的经静脉移植MSCs治疗球囊损伤的粥样硬化颈动脉,探讨MSCs对动脉损伤后修复的影响及可能的作用机制。方法制作颈动脉粥样硬化狭窄动物模型48只,分为MSCs移植组(n=30)和对照组(n=18)。MSCs移植组于球囊损伤前经外周血采集MSCs并体外培养扩增,于球囊损伤后即刻、1周和2周经静脉移植MSCs,而对照组给予等量生理盐水。于球囊损伤后4周收集血管标本,经免疫化学染色后观察血管病理形态学特点、计算新生内膜和中膜面积、检测增殖细胞核抗原(PCNA)以及ELISA法测定局部NO含量和RT-PCR检测eNOSmRNA表达。结果血管病理形态学检测显示,MSCs移植组颈动脉内皮细胞少量缺失,但无内皮的片状剥脱,管壁部分区域轻度增厚,管腔轻度狭窄,增厚处中膜可见少量泡沫细胞沉积,部分区域伴少量纤维组织增生,呈动脉粥样硬化早中期(脂纹-纤维斑块期)改变。与对照组比较,MSCs移植组新生内膜面积(NEA)和中膜面积(MA)均明显减少(P0.05);而两组间新生内膜/中膜面积比(I/M)无统计学意义。同时,血管壁PCNA测定显示:MSCs移植组PCNA阳性细胞率显著低于对照组,表明与移植组相比,对照组新生内膜增生程度更为明显。MSCs移植组损伤的颈动脉局部NO含量和eNOSmR-NA表达均明显高于对照组,差异具有统计学意义。同时,eNOSmRNA表达程度与4周时动脉内膜增生情况相关分析显示呈负相关。结论 MSCs静脉移植可明显降低球囊损伤动脉的新生内膜增生,这可能与损伤动脉局部eNOSmRNA表达和NO含量增加有关。     

骨髓间充质干细胞移植对损伤血管的内皮修复作用

目的探讨兔颈动脉粥样硬化狭窄血管成形术后,骨髓间充质干细胞(BMSC)移植对损伤血管内皮修复的影响及可能机制。方法制作兔颈动脉粥样硬化狭窄模型48只,随机分成BMSC移植组(n=24)和对照组(n=24)。体外培养兔BMSC,流式细胞仪鉴定BMSC表面标志,DAPI标记后备用。球囊损伤颈动脉的即刻,BMSC移植组以107/kg的细胞数经颈外动脉移植到损伤动脉局部,对照组注射等量的PBS液。术前及细胞移植后3、7、14及28天采集外周血用ELISA法测定血管内皮生长因子水平。移植后7天取材观察DAPI标记BMSC的归巢。移植后14天免疫组织化学染色检测损伤血管组织的血小板-内皮细胞黏附分子(CD31)的表达;移植后28天HE染色后测定损伤血管新生内膜面积、新生内膜面积/中膜面积及再狭窄率。结果 BMSC移植组在移植后各时间点血管内皮生长因子水平均显著高于对照组(P<0.01)。移植后7天BMSC移植组损伤血管的内膜表面见DAPI标记的BMSC。移植后14天血管内膜有CD31的连续性表达,对照组没有表达。与对照组比较,移植后28天BMSC移植组血管新生内膜面积(0.092±0.009比0.189±0.007,P<...     

间充质干细胞移植对兔粥样硬化颈动脉损伤后再狭窄的影响

目的探讨间充质干细胞（mesenchymals temcells,MSCs）对球囊损伤的粥样硬化颈动脉再狭窄的影响及可能的作用机制。方法制作颈动脉粥样硬化狭窄大白兔模型38只。分为MSCs移植组（n=28）和对照组（n=10）。MSCs移植组于球囊损伤前经外周血采集MSCs并体外培养扩增,于球囊损伤后即刻、1周和2周经静脉移植MSCs,而对照组给予等量生理盐水。于球囊损伤后4周收集血管标本,经免疫化学染色后观察血管病理形态学特点、计算新生内膜和中膜面积并检测增殖细胞核抗原（proliferating cell nuclear antigen,PCNA）。结果①MSCs移植组外周血分离MSCs经荧光激活细胞分类术（FCAS）鉴定,其表面抗原CD44阳性而CD34和CD45阴性,纯度达95％以上;②MSCs移植组颈动脉内皮细胞少量缺失,管壁部分区域轻度增厚,管腔轻度狭窄,增厚处中膜可见少量泡沫细胞沉积,部分区域伴少量纤维组织增生,呈动脉粥样硬化早中期（脂质条纹-纤维斑块期）改变,而对照组颈动脉见内皮细胞片状缺失,动脉管壁全周明显增厚,管腔狭窄较明显,内膜管腔面可见纤维组织增生形成纤维帽,纤维帽下中膜内可见较多的泡沫细胞沉积,并伴有淡红染无定形物质形成,呈动脉粥样硬化中晚期（纤维斑块-粥样斑块期）改变;⑧与对照组相比较,MSCs移植组新生内膜面积和中膜面积均明显减少,差异有统计学意义[（0．336±0．018）mm^2比（0．845±0．046）mm^2,P〈0．01;（0．245±0．017）mm^2比（0．951±0．024）mm^2,P〈0．01];而两组间新生内膜面积／中膜面积,差异无统计学意义[（1．371±0．158）比（1．534±0．014）,P〉0．05]。同时,血管壁PCNA测定显示：MSCs移植组PCNA阳性细胞率显著低于对照组（0．236％±0．014％比0．881％±0．017％,P〈0．05）。结论MSCs静脉移植可明显降低兔球囊损伤动脉粥样硬化颈动脉的新生内膜增生,促进损伤内皮再生。     

辛伐他汀对支架置入后兔腹主动脉内膜增生的影响

目的 观察辛伐他汀对兔腹主动脉支架置入后内膜增殖的影响.方法 30只新西兰大白兔随机分为对照组和辛伐他汀治疗组.采用含1.5%胆固醇的高脂饮食加腹主动脉内皮剥脱术制作兔腹主动脉粥样硬化模型.内皮剥脱术后第12周实验组和对照组服用阿司匹林25 mg/d,氯吡格雷12.5 mg/d, 3 d后,分别行支架置入术.术后实验组继续服用辛伐他汀5 mg/d,服药至第30天处死动物,取腹主动脉含支架段血管,进行血管壁组织形态学变化观察和检测细胞周期抑制蛋白P27kip1、增殖细胞核抗原(PCNA)在各组的表达量的变化.结果 血管超声发现内皮剥脱术后第10周实验组和对照组腹主动脉均可见有不同程度的粥样硬化斑块和血管内狭窄.组织形态学观察发现服用辛伐他汀的实验组兔腹主动脉支架段内的血管内膜厚度(0.107±0.072 mm,与对照组0.133±0.047 mm比,P=0.006)、新生内膜面积(0.975±0.084 mm2,与对照组1.350±0.043 mm2比,P=0.001)均明显降低,且血管的狭窄程度较轻(20.460%±2.325%,与对照组31.020%±1.904%比,P=0.002).实验组兔腹主动脉支架段内的血管新生内膜中的血管平滑肌细胞(VSMC)的胞核P27kipl蛋白表达量明显升高(7.149±0.305,与对照组2.997±0.310比,t=9.551,P＜0.05),而血管新生内膜中VSMC的胞核PCNA表达量明显降低(着色强度IS为3.003±0.192, 与对照组着色强度IS 5.268±0.475比,t=4.423,P＜0.05).结论 辛伐他汀能明显抑制支架置入术后血管内膜增生.其机制可能为通过上调P27kip1蛋白表达量,使增殖标志物PCNA表达量降低,而对VSMC增殖周期起负调控作用,达到抑制VSMC增殖和新生内膜的增生.     

阿司匹林对小型猪动脉粥样硬化的影响

目的探讨阿司匹林对早期动脉粥样硬化的干预作用。方法健康小型猪22头,随机分为对照组(n=6):给予正常猪饲料;高脂组(n=8):给予3%胆固醇高脂饮食;阿司匹林组(n=8):给予3%胆固醇高脂饮食 阿司匹林150 mg/d。高脂饮食4个月和6个月时,每组随机处死一半,定量测量动脉粥样硬化斑块厚度和斑块面积。结果3.0%胆固醇高脂饮食4个月就可以引起小型猪明显的动脉粥样硬化。高脂饮食4个月时,高脂组冠状动脉斑块厚度和截面积分别为107.2±45.7μm和0.113±0.05 mm2;阿司匹林组主动脉粥样硬化面积无明显减少,冠状动脉斑块厚度和截面积分别为74.2±24.7μm和0.093±0.05 mm2,与高脂组相比无统计学差异。高脂饮食6个月时,高脂组冠状动脉动脉粥样硬化斑块厚度为152.9±86.1μm、斑块/中膜厚度比0.85±0.49、斑块截面积为0.188±0.207 mm2、内膜/中膜面积比0.235±0.249;阿司匹林组主动脉粥样硬化面积明显减少,冠状动脉粥样硬化斑块厚度(47.8±19.8μm)、斑块/中膜厚度比(0.33±0.09)、斑块截面积(0.017±0.012 mm2)、内膜/中膜面积比(0.030±0.019),均明显低于高脂组(P<0.05或P<0.01)。结论阿司匹林对早期动脉粥样硬化有抑制作用。     

冠状动脉搭桥术后静脉桥再狭窄动物模型的建立

目的建立冠心病冠状动脉搭桥术后移植静脉桥再狭窄的动物模型。方法 26只新西兰兔随机分成3组:高脂移植组(n=10)、单纯移植组(n=10)、正常对照组(n=6),分别给予自体颈外静脉移植加高脂饲料、自体颈外静脉移植加普通饲料、普通饲料喂养。移植组均进行颈外静脉反向吻合于颈动脉的搭桥手术,术后用彩色超声检测血流量,证明静脉桥通畅。2个月后,用多普勒检测静脉桥血流量及内膜厚度,取组织标本作病理切片检查,以了解静脉桥有无血栓,内皮细胞及平滑肌细胞有无增生迁移及血管基质有无增生等。结果 (1)术毕所有静脉桥均通畅。(2)术后2个月彩色超声检查示高脂移植组与单纯移植组和正常对照组相比,静脉桥内膜有斑块形成,狭窄明显,内膜明显增厚。(3)术后2个月病理切片显示高脂移植组的静脉桥内皮细胞脱落、内膜增生、平滑肌细胞移行增殖和脂质沉积等典型的粥样硬化变化,而单纯移植组和正常对照组则不明显。结论兔颈外静脉反向吻合于颈动脉的静脉搭桥动物模型是可靠的,其为研究静脉桥术后再狭窄提供了既简单又较理想的模型。     

奥美沙坦对兔腹主动脉内皮损伤后过氧化物酶体增殖物激活受体γ及单核细胞趋化蛋白1表达的影响

目的:观察奥美沙坦对兔血管内膜损伤后过氧化物酶体增殖物激活受体γ(PPARγ)及单核细胞趋化蛋白1(MCP-1)表达的影响,探讨奥美沙坦预防动脉粥样硬化的可能机制.方法:雄性新西兰大白兔24只,随机分为3组:普通饲料喂养组(G1),高脂饮食喂饲加动脉内皮损伤组(G2),高脂饮食喂饲加动脉内皮损伤组加奥美沙坦治疗组(G3).G2、G3组持续给予1.5%的胆固醇喂养2周后行腹主动脉内膜剥脱术,G3组内膜剥脱术后第1天开始口服奥美沙坦10 mg·kg-1·d-1.3组均于8周后取兔腹主动脉行病理形态学观察,RT-PCR方法检测各组PPARγ和MCP-1 mRNA的表达.结果:高胆固醇喂养8周后,G3组较G2组内膜厚度减少71%,内膜面积减少37%,内膜厚度与中膜厚度比减少34%,内膜面积与中膜面积比减少31%.G2组较G1组,PPARγ和MCP-1均表达增加,G3组PPARγ表达高于G2组(P<0.05),而MCP-1表达低于G2组(P<0.05).结论:奥美沙坦可明显抑制血管损伤后的内膜增生并改善血管重构,其机制可能与调节PPARγ,从而影响MCP-1水平,改善动脉粥样硬化有关.     

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.     

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.     

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.     

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.     

Presence of immunoreactive growth hormone and prolactin in the ovine pineal gland

Abstract: The use of antisera raised against bovine growth hormone (GH) and ovine prolactin (PRL) enabled the detection of related immunoreactive (ir) sequences of proteins in ovine pineal tissue. The isolation of PRL-like ir-material was accomplished using a 0.25 M ammonium sulphate (pH 5.5) extraction followed by ethanol precipitation, whereas the resulting 2.0 M ammonium sulphate (pH 7.0) precipitate contained a GH-like immunoreactivity. Gel chromatography of the GH-like immunoreactivity (Sephadex G-100) indicated the presence of several GH-like fragments ranging in the M_r range of 7,000 to 55,000. Analyses of the PRL-like ir-material found in pineal tissue on HPLC using a TSK 545-DEAE column led to the resolution into a single peak of immunoreactivity. A single peak of activity was also observed following chromatofocusing and hydrophobic interaction chromatography of the ir-peak from the TSK 545-DEAE column. The PRL-like ir-material inhibited the binding of [¹²⁵I]ovine PRL-S14 to anti-ovine PRL antibodies without showing an affinity for binding to anti-rat PRL or anti-bovine GH antibodies. Scatchard analysis of the binding of pineal PRL-like ir-material and pituitary ovine PRL-S14 to liver membranes from day-20 pregnant rats revealed similar affinity constants (K_a of 4.7 ± 0.2 × 10⁹ M^-1). In addition, the replication of Nb 2 Node rat lymphoma cells was stimulated by pineal PRL-like ir-material, an effect known to be specific for lactogenic hormones. The pineal PRL-like immunoreactivity appeared on sodium dodecyl sulfate polyacrylamide gels as a single major band of M_r 24,000. The functional status of PRL-and GH-like ir-material in the ovine pineal remains to be determined, but evidence is presented that the overall protein synthesis rate of the rat pineal responded to circulating concentrations of PRL.