体外循环自体血预充技术对全身炎性反应的影响

目的 研究体外循环采用自体血预充技术对全身炎性反应相关指标的影响.方法 32例非急诊手术首次接受体外循环下心脏冠脉搭桥的患者,依性别（男女比例）、年龄、体重、身高、体表面积（BSA）和射血分数（EF）进行配对后分为两组：自体血预充组（16例）和经典预充组（16例）.自体血预充组：用1250 ml晶体液和8000 IU肝素预充,体外循环开始前先采用自体血预充技术置换出大部分最初预充液,置换过程中严密监视血流动力学变化,维持平均动脉压（MAP）在50 mm Hg以上.整个过程依患者血流动力学耐受程度决定.经典预充组：1250 ml晶体液和8000 IU肝素预充.两组患者心肌保护均采用Calafiore温血停跳液灌注,体外循环中保持温度35.0 ℃～35.5 ℃,流量 2.5～2.8 L·min-1·m-2.所有患者按标准手术步骤进行手术,先完成全部远端吻合口后,开放升主动脉再逐一完成近端吻合.平均体外循环时间64 min,阻断升主动脉时间37 min,平均每例搭桥3.0支.手术结束前将体外循环系统中余血全部回输给患者.结果 自体血预充组平均置换出（885±161）ml的最初预充液,患者体外循环中、手术结束时、术后6 h、术后1 d的HCT水平均明显高于经典预充组（P＜0.05）.90%自体血预充组患者围术期免于输血,而经典预充组患者未输血比例为68%.患者体外循环结束和体外循环后6 h动脉血IL-6水平低于经典体外循环组（P＜0.05）.经典预充组患者体外循环开始和结束时IL-8、TNF-α水平高于自体血预充组（P＜0.05）.结论 体外循环应用自体血预充技术能减少血液稀释,减少围术期输血量,一定程度地抑制IL-6、IL-8和TNF-α炎症介质的升高.     

逆行自体血预充在体外循环心脏瓣膜置换手术中的应用

目的:探讨逆行自体血预充(RAP)对心脏瓣膜置换手术中血液稀释及围术期输血量的影响。方法:将30例心脏瓣膜置换术患者随机分为RAP组和常规预充组,每组15例。常规预充组采用常规晶体预充液预充,RAP组使用患者自身血液替换部分常规晶体预充液。监测体外循环前、中、结束时以及术后1h、3h等各个时间点的乳酸(Lac)和红细胞压积(Hct)水平,并观察两组患者围术期输血量和胸腔引流量。结果:逆行自体血预充能有效减轻心脏瓣膜置换手术中的血液稀释程度,维持术中较高的Hct水平,对机体血液有较好保护作用,有效减少了围术期输血量。结论:逆行自体血预充能有效减轻心脏瓣膜置换手术中的血液稀释程度,维持术中较高的Hct水平,对机体血液有较好保护作用,有效减少围术期输血量。     

比较两种胶体预充液对婴幼儿心脏直视手术治疗效果的临床研究

目的:对比体外循环(extracorporeal circulation,ECC)中6%羟乙基淀粉(HES)130/0.4与3.3%白蛋白(HA)预充对心脏手术患儿围术期血浆胶体渗透压(plasmn colloid osmotic pressure,COP)、液体平衡、肾功能及术后容量治疗的影响。方法:选择美国麻醉医师协会(ASA)Ⅰ-Ⅱ级,5～10 kg患儿行心内直视手术60例,随机分为两组,分别采用6%HES 130/0.4(HES:n=30)和3.3%HA(HA:n=30)进行体外循环预充。观察患儿临床恢复情况、围术期各时点血浆胶体渗透压变化情况、各种液体出入量、出血量和血制品使用情况。结果:HES组ECC预充液、ECC中及手术结束时COP均明显高于HA组(P<0.01);至ICU 6 h,两组COP均恢复至术前水平。ECC中HES组液体总入量明显低于HA组[(2.8±4.1)vs.(6.2±4.4)mL/kg,P<0.01],ECC后HES组输血量明显低于HA组[(27±34)vs.(59±34)mL,P<0.01]。两组血肌酐变化无差异。结论:6%HES 130/0.4能有效维持ECC中COP,减少液体正平衡及减少输血,因此6%HES 130/0.4可以替代3.3%HA于婴幼儿心内直视术ECC中预充使用。     

逆行自体血液预充和改良超滤在儿童体外循环中的应用

目的探讨逆行自体血液预充技术(RAP)和改良超滤技术(MUF)联合应用对儿童体外循环的影响.方法40例体外循环手术患儿,随机分为实验组(n=20)和对照组(n=20).实验组联合应用逆行自体血液预充技术和改良超滤技术,对照组不进行上述两项技术.分别记录两组患儿体重,体表面积,体外循环时间及主动脉阻断时间,逆行自体血液预充置换液量,转前、转中、术后红细胞压积,呼吸机使用时间及围手术期临床用血量.结果两组患儿体重,体表面积,体外循环时间及主动脉阻断时间差异无统计学意义(P＞0.05).转前、转中红细胞压积比较差异亦无统计学意义(P＞0.05);实验组可减少预充液量,转后红细胞压积实验组(32.50±3.04)%高于对照组(24.05±1.47)%,差异具有统计学意义(P＜0.05),实验组呼吸机使用时间为(106.50±47.85)min,围手术期临床用血量为(0.15±0.26)U,对照组呼吸机使用时间为(195.75±77.94)min,围手术期临床用血量为(0.78±0.62)U,实验组均少于对照组,差异有极显著性意义(P＜0.01).结论逆行自体血液预充技术和改良超滤技术在儿童体外循环手术中联合应用可以减少临床用血量,降低输血相关风险,促进患儿术后恢复.     

528例先天性心脏病患儿心内直视手术无血预充体外循环的管理

目的:总结先天性心脏病(先心病)患儿心内直视手术无血预充体外循环(CPB)的方法及管理经验。方法:回顾性分析重庆医科大学附属儿童医院2013-11至2016-11收治的先心病528例患儿心内直视手术无血预充体外循环情况。所有患儿均行气管插管全身麻醉,体外循环下完成心内畸形矫治手术,选用改良体外循环管路减少预充量,依据患儿术前红细胞压积(HCT)水平,选用急性等容性血液稀释性自体输血技术,使用血液回收机行回收式自体输血技术减少血液丢失,依据体外循环情况行常规超滤、平衡超滤及改良超滤,实现无血体外循环。结果:528例不同体重患儿的预充量:5 kg(160~180)ml,5~12 kg(220~250) ml,12~28 kg(300~350 ml),28kg(600~650)ml;入室后的平均HCT(36.1±5.9)%,实施无血预充,体外循环5 min时HCT(24.3±3.1)%,停机前HCT(24.8±3.0)%,出室前HCT(32.1±3.8)%。其中有43例(8.1%)患儿体外循环过程中输注库存血,停机后有25例(4.8%)患儿输注库血。行急性等容性血液稀释性自体输血的患儿共72例(13.6%),共放血15 520 ml。术中195例复杂先心病患儿中有189例(96.9%)使用血液回收机,333例单纯房间隔缺损、室间隔缺损及合并动脉导管未闭患儿中,仅有3例(9.0%)使用血液回收,且均为稀有血型患儿。体外循环过程中使用常规超滤223例(42.2%),平衡超滤211例(40.0%)及改良超滤247例(46.8%)。结论:小儿先心病手术的无血体外循环有其复杂性及特殊性。对于体重和HCT水平合适的患儿,使用改良体外循环管路,结合急性等容性血液稀释及回收式自体输血、超滤技术,无血预充能够安全地在儿童先心病手术体外循环中实施,从而实现节约用血,减少异体输血的并发症,促进患儿早日康复。     

经皮冠状动脉介入治疗中静脉注射那屈肝素的抗血栓疗效及安全性评价

目的比较经皮冠状动脉介入治疗(PCI)中静脉注射那屈肝素或普通肝素的抗血栓疗效及安全性.方法采用前瞻性、随机、单盲、多中心研究的设计,共入选98例因患冠心病需行PCI的患者,随机分为那屈肝素组(0.075 ml/10 kg,手术时间超过1 h补充半量)及普通肝素组(100 U/kg,手术时间超过1 h补充2000 U).PCI前静脉注射那屈肝素或普通肝素.那屈肝素组前22例患者分别在注射前、注射后8 min、1 h、2 h和4 h,用发色底物法测定血浆抗Ⅹa因子活性.出血程度的判断根据TIMI研究的标准进行.结果 (1) 性别、年龄、体重、血压、血红蛋白含量、红细胞压积、合并糖尿病的例数、冠心病类型、进行冠状动脉介入治疗的部位、介入治疗的手术方式及术前血浆cTNI>2 ng/ ml的例数在二组之间分布均衡,差异均无统计学意义;(2) 那屈肝素组前22例患者血浆抗Ⅹa因子活性测定显示,用药前、用药后8 min、1 h、2 h及4 h血浆抗Ⅹa因子活性分别为(0.10±0.00) IU/ ml、(1.89±0.24)IU/ ml、(0.96±0.24) IU/ ml、(0.47±0.13)IU/ ml和(0.30±0.12) IU/ ml.注射那屈肝素后8 min及1 h,所有患者血浆抗Ⅹa因子活性均在治疗水平(>0.5 IU/ ml),注射后2 h及4 h分别仅有45%及9%的患者血浆抗Ⅹa因子活性维持在治疗水平.(3)那屈肝素组术后血红蛋白数量、红细胞压积及出血指数分别为(129.5±13.6) g/L、(39.0±3.9)%和(1.16±5.80) g/L,与普通肝素组相似[分别为(125.5±14.9) g/L、(37.9±4.6)%和(0.90±6.5) g/L,P值分别为0.175,0.205和0.858);(4) 二组均无显微镜下血尿、无黑便或大便隐血阳性的患者;均无按TIMI试验标准所诊断的大出血或轻度出血的患者,无需要输血的患者;无穿刺部位的血肿;(5) PCI术后30 天内二组均无死亡、心绞痛复发及需行血管再通术等临床事件发生,那屈肝素组有1例患者PCI术后发生急性心肌梗死,普通肝素组无发生心肌梗死的病例,二组之间差异无统计学意义.结论 PCI术前注射那屈肝素能达到理想的抗血栓疗效; 与普通肝素相比,那屈肝素不增加出血事件和心血管病事件的发生率.     

聚乙二醇-牛血红蛋白在体外循环中对炎性因子的影响

目的采用颈静脉-股动脉部分转流的体外循环(CPB)模式,观察以聚乙二醇-牛血红蛋白(PEG-bHb)代替预充液中的胶体溶液预充进行的体外循环中炎性因子的变化。方法选取13只小尾寒羊,根据CPB预充液成分的不同随机分为两组:实验组(P组,n=7)在体外循环前经颈静脉放自体血(15%)后,在体外循环晶体预充液中加入等量PEG-bHb,在CPB转流结束后,将保存的羊自体血输入体内;对照组(C组,n=6)应用常规体外循环预充(706羟乙基淀粉和乳酸林格氏液)方案。分别在CPB前(T1)、CPB开始30min(T2)、CPB结束后1h(T3)、4h(T4)、8h(T5)、24(T6)、48h(T7)各时点抽取动脉血样本。ELISA法检测血清白介素6(IL-6)、白介素8(IL-8)和肿瘤坏死因子(TNF-浕)浓度。结果组内与术前相比,所有细胞因子均呈现上升趋势;组间比较,两组各时点炎性因子浓度无显著性差异。结论PEG-bHb作为一种有效的血液替代品,不会增加体外循环炎性因子的产生,可安全应用于体外循环预充。     

法乐四联症根治术术中血液保护策略

探讨法洛四联症心内直视手术中的血液保护方法。方法 分析2010年1月至2014年5月我院75例法洛四联症根治术患者资料,按我院开始行血液保护措施时间将患者分为两组,对照组（31例）和血液保护组（44例）,两组患者采用常规预充方法。血液保护组预计体外循环（ECC）转流中红细胞压积（HCT）大于30%时,经腔静脉插管放血,转流中维持HCT 25%,停机后给予改良超滤提高HCT至30%,并保持体温35 ℃～36 ℃;对照组HCT大于30%不予处理,停机后HCT低于30%给予输注红细胞悬液。比较两组患者体外循环预充用血量和预充用血浆量、血红蛋白（Hb）、胶体渗透压（COP）、乳酸值（Lac）、尿液颜色等。结果 所有患者均痊愈出院,无严重脏器损害。预充用血量对照组明显高于血液保护组（180.0ml/121.4ml）（P<0.05）,但预充用血浆量两组患者比较未见统计学差异（P>0.05）。转中Hb、COP以及转后Hb两组患者比较未见统计学差异（115.5ml/121.5ml）（P>0.05）,转后血液保护组COP高于对照组（P<0.05）,但转后Lac血液保护组明显低于对照组（P<0.05）,对照组出现血红蛋白尿比例高于血液保护组（P<0.05）。结论 法洛四联症手术中综合应用血液保护措施安全可行,能有效减少围术期用血量,有利于患者恢复。     

经皮冠状动脉介入治疗中静脉注射不同剂量那屈肝素的抗血栓疗效比较

目的比较冠状动脉介入治疗术(PCI)中静脉注射2种不同剂量那屈肝素的抗血栓疗效,明确取得理想抗血栓疗效的最佳剂量.方法采用前瞻性、随机、双盲的设计,共入选42例因患冠心病需行PCI术的患者,随机分为小剂量那屈肝素组(0.075 ml/10 kg)及大剂量组(0.1 ml/10 kg).PCI术前静脉注射那屈肝素,分别在注射前、注射后8 min、1 h、2 h和4 h,用发色底物法测定血浆抗Ⅹa因子活性.同时还观察了出血指数(定义为PCI治疗术后24 h内血红蛋白的下降值)及30 d内出血事件.结果 (1)小剂量组注射那屈肝素前、注射后8 min及1 h血浆抗Ⅹa因子活性分别为(0.10±0.00) IU/ml、(1.89±0.24) IU/ml、(0.96±0.24) IU/ml,均与大剂量组相应时间点的血浆抗Ⅹa因子活性[分别为(0.10±0.00) IU/ml,(1.89±0.30) IU/ml,(0.93±0.14) IU/ml]相似(P值分别为0.162、0.962和0.702).那屈肝素注射后2 h及4 h,小剂量组抗Ⅹa因子活性[分别为(0.47±0.13) IU/ml和(0.30±0.12) IU/ml]低于大剂量组[分别为(0.75±0.14) IU/ml和(0.45±0.08) IU/ml,P值均小于0.001]. (2)小剂量组的出血指数(3.3±3.8)g/L与大剂量组(0.2±6.4)g/L相似(P=0.061).(3)二组30 d内均未发现根据TIMI试验标准确定的大出血或轻度出血,均未发生死亡、心绞痛复发、心肌梗死及需行血管再通术等临床事件.结论 PCI术前注射二种剂量的那屈肝素均能达到理想的抗血栓效果,其中小剂量组能维持其有效的抗血栓疗效1 h,大剂量组能维持长达2 h的抗血栓效果.     

抑肽酶在心内直视手术中的应用

报告体外循环条件下应用大剂量抑肽酶对术后出血、血液各成分及输血量的观察。分为实验组（７例）、对照组（８例）。麻醉后由动脉或静脉放适量自体血，体外循环结束后回输给患者。实验组放血后静脉滴注抑肽酶２００万ｋＩＵ，以后持续用微量泵输入抑肽酶２５万ｋＩＵ／ｈ，直至手术结束；体外循环预充液中加入抑肽酶２００万ｋＩＵ，其余预充液两组相同。结果发现抑肽酶能明显地减少术中及术后出血，实验组术后２４ｈ出血量较对照组减少５６．４％，抑肽酶对血小板数及其它血液成分无明显影响。     

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.     

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.     

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.