血管紧张素Ⅱ对培养血管内皮细胞核因子-κB激活及厄贝沙坦干预研究

目的观察血管紧张素Ⅱ(AngⅡ)刺激人脐静脉血管内皮细胞(HUVEC)核因子-κB(NF-κB)激活与其对肿瘤坏死因子-α(TNFα)、白介素-6(IL-6)表达的影响及血管紧张素1型受体(AT1R)拮抗剂厄贝沙坦(irbesartan，Irb)干预后的变化，以探讨AngⅡ／NF-κB在动脉粥样硬化(AS)致病机制中的作用和Irb可能的抗AS效应。方法体外培养HLIVEC，测定AngⅡ刺激下NF-κB亚单位p65的核易位阳性率、TNFα、IL-6的时间与浓度反应曲线；然后将分盘于24孔板的细胞随机分为5组(n=6)：正常培养对照组、AngⅡ刺激组，AngⅡ和3种不同浓度的Irb共孵育组；采用细胞ELISA、免疫细胞化学分析分别测定TNFα、IL-6的含量和NF-κBp65的核易位阳性率。结果AngⅡ(1nmol／L-5μmol／L)刺激HUVEC表达TNFα、IL-6呈时间与浓度依赖性，其表达高峰分别为12～24h、6～12h，NF-κBp65核易位阳性率亦呈时间浓度依赖性，高峰在1～4h。厄贝沙坦(0．01μmol／L、0．1μmol／L、1μmol／L)均能显降低TNFα和IL-6表达与NF-κBp65核易位阳性率。结论AngⅡ以浓度和时间依赖方式刺激HUVEC NF-κB激活与TNFα、IL-6表达，厄贝沙坦抑制HUVEC NF-κB激活与TNFκ、IL-6表达，提示AngⅡ／NF-κB信号途径在促进AS发病机制中起重要作用，拮抗AT1R或抑制NF-κB有可能减轻或抑制AS进展。     

人外周血单核细胞人白细胞抗原-DR表达和细胞因子水平的增龄性改变

目的研究人外周血单核细胞（PBMC）人白细胞抗原DR的表达和单核细胞体外分泌细胞因子水平的增龄性改变。方法352例不同年龄的体检者按年龄分为A组120例（20-69岁）、B组85例（70-79岁）、c组98例（80-89岁）、D组49例（90～102岁）。用流式细胞仪检测PBMC表面人白细胞抗原（HLA）-DR的表达;每组随机抽取10人,用ELISA方法检测经内毒素（LPS）N激前后PBMC分泌肿瘤坏死因子-α（TNF—α）、白细胞介素（1L）-6、IL-10等细胞因子的水平,并比较各年龄组PBMC表面HLA—DR表达的变化以及分泌TNF-α、IL-6、IL-10等细胞因子水平的变化。结果A,B,C,D各组之间PBMC表面HLA—DR的表达有显著性差异（F=159．712,P=0．000）,且不同年龄组人群PBMC表面HLA—DR的表达呈随龄性增加（r=0．744,P=0．000）;LPS刺激前各年龄组人群PBMC分泌TNF-α,IL-6,IL-10细胞因子的水平无显著性差异（P〉0．05）;LPS刺激后各年龄组人群PBMC分泌TNF-α,IL-6,IL-10细胞因子的水平较LPS刺激前均有明显增高（P〈0．05）;将LPS刺激后各组PBMC分泌细胞因子的水平进一步行组内比较发现,与A组相比,B,C,D各组分泌TNF-α、IL-6的水平明显减低（P〈0．05）,分泌IL-10的水平明显增高（P〈0。05）。结论人PBMC细胞免疫功能呈随龄性改变,其表面HLA—DR的表达呈随龄性增加;LPS刺激前各年龄组人群PBMC分泌TNF-α,IL-6,IL-10细胞因子的水平无显著性差异;而LPS刺激后,70岁以上老年人PBMC分泌TNF-α和IL-6的水平明显减低,分泌IL-10的水平明显增高。     

枸橼酸对内毒素刺激下单核细胞细胞因子分泌的影响

目的:通过体外细胞培养,观察不同浓度枸橼酸对内毒素(LPS)诱导的单核细胞分泌细胞因子功能的影响。方法:采用标准方法体外培养人类单核细胞株(THP-1),加入适量枸橼酸三钠(TSC)使其体外培养液TSC浓度分别为0、0.5 mmol/L、1.0 mmol/L,并给予不同浓度LPS(0.05μg/ml、0.1μg/ml、1μg/ml)刺激,分别于刺激后6h、12h、24h、48h用CCK-8试剂盒测定细胞活性、ELISA试剂盒测定上清液细胞因子白细胞介素6(IL-6)、肿瘤坏死因子α(TNF-α)水平及血气分析仪测定培养基内离子钙(Ca~(2+))水平。使用正常培养条件下的单核细胞做为对照组。结果:不同浓度TSC对单核细胞活性无抑制作用(P0.05),但对不同时间点LPS诱导的单核细胞分泌细胞因子(TNF-α和IL-6)功能有一定影响,培养基TSC浓度0.5 mmol/L和1.0 mmol/L时,培养12h和24h TNF-α的分泌量显著高于对照组(P0.01);TSC浓度为0.5 mmol/L时,IL-6在24h开始出现分泌增高趋势,48h达到峰值(P0.05),TSC浓度1.0 mmol/L显著抑制IL-6分泌(P0.01)。结论:本实验采用的TSC浓度不存在细胞毒性,单核细胞在此浓度下,受LPS刺激时表现出TNF-α分泌亢进的现象,而IL-6的分泌则表现出TSC低浓度下亢进,高浓度下受抑制的趋势。     

脑出血患者血肿周围组织炎性反应与细胞因子表达的相关性

目的 探讨脑出血患者血肿周围组织炎性反应与细胞因子表达的相关性。方法 将30例脑出血患者作为出血组，于血肿旁约1cm处取少许脑组织.按发病到手术时间，将出血组分为〈6h组（6例），6～12h组（7例），12～24h组（5例），24～72h组（6例），〉72h组（6例）。从前两组中选7例患者，在手术入颅路径上远离血肿处取少许脑组织为对照组。应用HE染色、免疫组化及逆转录-聚合酶链反应（RT—PCR）等技术观察炎性细胞浸润、胶质细胞增生，肿瘤坏死因子（TNF）-α的蛋白及mRNA、白细胞介素（IL）-1β及IL-6mRNA的表达情况.结果 光镜观察显示：对照组、〈6h组血肿周围组织基本正常，6～12h组损伤较轻，12～24h组损伤较重，24～48h组损伤严重，以后逐渐好转，8d时与对照组相似.免疫组化显示：中性粒细胞、淋巴细胞、巨噬细胞浸润从6～12h逐渐明显，12～72h达高峰（P〈0．05），胶质细胞增生从12～24h开始增加，24h以后明显增加（P〈0．01），TNF—α蛋白表达从6～12h开始增加，12～24h达高峰（P〈0．05），以后逐渐减少；RT—PCR显示：TNF—α mRNA与其蛋白表达基本一致，IL-1B和IL-6mRNA的表达于12～72h达高峰（P〈0．01），以后有下降趋势。相关分析显示：中性粒细胞、淋巴细胞、巨噬细胞的浸润和小胶质细胞的增生与TNF—α蛋白和mRNA、IL-1B、IL-6的mRNA表达呈显著正相关（P〈0．05），星形胶质细胞的增生与TNF—α蛋白和mRNA表达无相关性，与IL-1B、IL-6mRNA表达呈显著正相关（P〈0.05）。结论 脑出血后血肿周围组织炎性反应与细胞因子的表达有密切关系。     

姜黄素对内毒素脂多糖诱导的库普弗细胞分泌炎症细胞因子的抑制作用

[目的]观察姜黄素对内毒素脂多糖（LPS）诱导的库普弗细胞（KC）分泌炎症细胞因子的影响。[方法]分离并培养KC48h后，分设不同浓度姜黄素组，作用于KC3h，确立无毒性的剂量范围；分正常组、LPS组、LPS加姜黄素组（分3种浓度），在添加姜黄素1h后，加LPS（0．1μg／ml培养液）刺激2h。取上清用ELISA法测定肿瘤坏死因子α（TNF-α）、放免法测白细胞介素1β（IL-1β）和IL-6水平；并以细胞免疫荧光化学法观察细胞TNF-α蛋白的表达和分布。[结果]不同浓度组姜黄素均能显著降低TNF-α、IL-1β和IL-6的水平以及细胞TNF-α蛋白的表达，量效关系显著。[结论]姜黄素对LPS诱导的KC炎症细胞因子分泌有显著的抑制作用。     

LOX-1/NF-κB信号途径对ox-LDL刺激的人脐静脉内皮细胞炎症因子表达的影响及氟伐他汀的干预作用

目的：探讨血凝素样氧化型低密度脂蛋白受体-1（LOX-1）/核因子（NF）-κB信号途径对氧化低密度脂蛋白（ox-LDL）刺激的人脐静脉内皮细胞（HUVECs）炎症因子表达的影响及氟伐他汀的干预作用。方法：设立不同浓度的ox-LDL刺激组,LOX-1中和抗体干预组,NF-κB抑制剂吡咯烷二硫代氢基甲酸盐（PDTC）干预组,氟伐他汀干预组及空白对照组;检测细胞上清液中肿瘤坏死因子（TNF）-α,白细胞介素（IL）-6的浓度。结果：25mg/L、50mg/L、100mg/L浓度的ox-LDL刺激组24h后上清液TNF-α浓度分别为：（32.34±2.46）pg/ml、（96.43±8.36）pg/ml、（62.79±4.64）pg/ml,IL-6浓度分别为：（264.71±15.06）pg/ml、（630.70±17.77）pg/ml、（378.62±16.33）pg/ml,均较空白对照组TNF-а（22.99±3.55）pg/ml、IL-6（80.37±8.29）pg/ml水平显著升高（P〈0.05~0.01）;NF-кB抑制剂PDTC和LOX-1中和抗体干预后上清液TNF-α浓度较50mg/L ox-LDL刺激组显著下降（P〈0.01）。不同浓度氟伐他汀（0.01μmol/L、0.1μmol/L、1μmol/L）干预HUVECs 24h后上清液TNF-α浓度分别为（73.84±6.50）pg/ml、（42.59±6.45）pg/ml、（23.55±4.27）pg/ml;IL-6浓度分别为（549.0±20.23）pg/ml、（434.56±22.4）pg/ml、（302.42±21.30）pg/ml,较50mg/L ox-LDL刺激组显著下降（P〈0.05~0.01）。结论：氧化低密度脂蛋白可刺激人脐静脉内皮细胞上清液中炎症因子TNF-α和IL-6的表达,在25~50mg/L剂量范围内呈显著的剂量-效应关系。氟伐他汀可浓度依赖性抑制人脐静脉内皮细胞上清液中炎症因子TNF-α和IL-6的表达。     

IL-1β对人冠状动脉平滑肌细胞妊娠相关血浆蛋白A分泌的影响

目的探讨IL-1β对人冠状动脉平滑肌细胞（HCASMC）分泌妊娠相关血浆蛋白A（PAPP-A）的影响。方法培养HCASMC,至第5～7代时,分别加入20μg/L和0μg/L的IL-1β（0μg/L组为对照组）,分别孵育2、4、8、24、36 h后,收集细胞培养上清液;采用IL-1β（0、5、20、4μg/L）刺激HCASMC 6 h后分别收集细胞和细胞培养上清液。用ELISA法检测细胞培养上清液内PAPP-A的表达量。结果IL-1β组PAPP-A表达量在2 h时开始增加,8、24和36 h时其浓度显著高于对照组（P均〈0.05）;随着IL-1β剂量增加,PAPP-A的表达量不断升高,其中20μg/L和40μg/L组的浓度均显著高于0μg/L组的浓度（P均〈0.05）。结论IL-1β可使HCASMC分泌PAPP-A增加,并呈时间和剂量依赖性。     

逆行灌注对心脏瓣膜置换术患者炎性细胞因子水平的影响

目的探讨经冠状静脉窦逆行灌注方法对风湿性心脏病心脏瓣膜置换术患者血浆炎性细胞因子水平的影响。方法 56例风湿性心脏病行体外循环（CPB）下心脏瓣膜置换术患者随机分为主动脉根部顺行灌注心肌停跳液（AC）组和持续冠状静脉窦逆行灌注心肌停跳液（RC）组各28例。手术前后采静脉血检测两组血浆肿瘤坏死因子（TNF）-α、白细胞介素（IL）-6和IL-10水平。结果两组患者血浆TNF-α、IL-6和IL-10的浓度在CPB转流30min至术后6 h与术前比较明显升高（P〈0.05）;RC组患者TNF-α、IL-6在术后即刻至术后6 h浓度明显低于AC组,IL-10浓度明显高于AC组（P〈0.05或〈0.01）,术后24 h IL-6浓度仍低于AC组,IL-10浓度高于AC组（P均〈0.05）。结论逆行灌注能有效抑制CPB过程中促炎细胞因子TNF-α和IL-6的释放,促进抗炎细胞因子IL-10的释放,调节促炎因子和抗炎因子之间的平衡,从而减轻体外循环期间炎症反应。     

粉防己碱对缺氧／复氧乳鼠心肌细胞前炎症因子的影响

目的：研究粉防己碱对离体培养的大鼠心肌细胞在缺氧／复氧条件下对前炎症因子：肿瘤坏死因子（TNF—α）、自细胞介素-1（IL-1G）、白细胞介素-6（IL-6）的影响。方法：乳鼠心肌细胞体外培养心肌细胞成功后,随机分为三组：对照组、缺氧／复氧（A／R）组、粉防己碱（Tet）组。对照组：不进行A／R处理,正常情况下持续培养26h;A／R组：在高纯度氩气,无糖无血清培养基条件下培养2h,复氧开始时加入0．9％盐水,再复氧培养24h;Tet组：预先给予终浓度为30μmol／L的Tet孵育60min,再在无血清低糖DMEM培养基缺氧孵育2h,然后继续复氧培养24h;检测各组在复氧24h后的TNF-α、IL-1β、IL－6的水平。结果：试验24h后A／R组、Tet组前炎症因子TNF－α[（682．65±32．59）、（388．94±17．22）],IL～1β[189．11±8．29）,（109．46±7．62）],IL－6[（78．45±2,74）、（40．91±1．53）]水平（pg／ml）均较对照组的[（211．44±14．20）,（59．64±2．43）,（23．99±3.24）]显著升高（P〈0．01）,Tet组前炎症因子TNF—α、IL-1β、IL-6水平均分别显著低于A／R组的（P〈0．01）。结论：Tet可以抑制IKB—α磷酸化,显著减少前炎症因子TNF—α、IL-6的产生,减轻心肌缺血／再灌注损伤。     

卡维地络对充血性心力衰竭患者促炎细胞因子的影响

目的：观察卡维地络对充血性心力衰竭（CHF）患者促炎细胞因子浓度的影响。方法：选择66例CHF患者，随机分为常规治疗组和卡维地络治疗组，32例健康体检者为正常对照组。用双抗体夹心ELISA法测定血浆肿瘤坏死因子-α（TNF-α）、白介素-6（IL-6）和IL-1β的浓度，分析其与CHF程度的关系。结果：（1）CHF患者三种细胞因子浓度均明显高于正常对照组（P〈0．05或〈0．01），CHF程度越重细胞因子浓度越高（P〈0．01）；（2）治疗后卡维地络组心功能分级左室收缩末内径较治疗前显著降低（P均〈0．05），左室短轴缩短率（LVFS）、每搏量（SV）、左室射血分数（LVEF）较治疗前显著升高（P〈0．05～〈0．01）；常规治疗组仅LVEF显著升高（P〈0．05）；治疗后卡维地络组LVEF、LVFS较常规治疗组显著升高（P〈0．05）；（3）治疗后卡维地络组三种细胞因子浓度显著降低（P〈0．01或〈0．05）；常规治疗组TNF—α、IL-6降低（P〈0．05），而IL-1β水平降低不显著。结论：CHF患者促炎细胞因子浓度升高，可作为判断心衰严重程度的指标。卡维地络能有效抑制促炎细胞因子的产生，改善心功能和心室重构。     

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.