左心室瘢痕负荷SPECT相位分析法检测及其对心脏再同步治疗疗效的影响

目的 观察慢性心力衰竭患者心脏再同步治疗(CRT)后有反应和无反应者之间左心室瘢痕负荷的差异性,评价左心室瘢痕负荷对CRT疗效的影响.方法 对30例2006年至2010年因慢性心力衰竭在南京医科大学第一附属医院接受CRT的患者进行静息核素心肌显像检查,应用相位分析技术检测左心室瘢痕负荷、收缩期相位时间标准差( phase S D)和带宽(BW)并用来评价心脏同步性.以术后6个月超声心动图的检测结果及随访6个月内是否因心力衰竭住院作为分组标准,左心室射血分数(LVEF)提高≥0.05且无因心力衰竭住院的患者入选反应组,LVEF提高＜0.05或者入院1次以上的患者入选无反应组,观察两组之间左心室瘢痕负荷和同步性指标之间的差异.结果 30例患者中反应组19例(男8例),无反应组11例(男8例).两组之间术前临床资料相似,年龄、性别均差异无统计学意义;有反应组术前QRS时限显著大于无反应组[(163.0±7.7)ms对(134.6±11.8) ms,P＜0.05];两组术前LVEF差异无统计学意义,但术后有反应组显著高于无反应组(0.49±0.02对0.33±0.15,P＜0.01).两组患者左心室瘢痕负荷和CRT术后左心室同步性差异具有统计学意义,有反应组患者的左心室瘢痕负荷明显低于无反应组(24.6％±3.6％对36.5％±3.9％,P=0.022);有反应组左心室同步性较好,收缩期相位时间标准差明显小于无反应组(28.1°±4.4°对56.1°±6.9°,P＜0.01),收缩期带宽明显小于无反应组(88.0°±13.9°对170.1°±24.4°,P＜0.01).左心室瘢痕负荷和心脏同步性对CRT疗效具有明显的影响.结论 接受CRT的慢性心力衰竭患者,左心室瘢痕负荷和CRT术后心脏同步性与CRT疗效密切相关.     

心脏再同步化治疗起搏参数优化对心脏同步性及心功能的影响

目的 应用组织多普勒研究心脏再同步化治疗(CRT)术后A-V、V-V间期优化对心脏同步性能及心功能的影响,探索A-V、V-V间期优化在增强CRT临床疗效中的作用.方法 32例慢性心力衰竭患者接受CRT治疗,于术后7天、3个月、6个月进行A-V、V-V间期优化,观察心脏同步性和心功能变化.采用彩色超声诊断仪进行图像采集及下线分析.结果 经观察,术后7天、3个月、6个月的A-V间期需行优化的例数分别为28例、10例、6例,V-V间期需行优化的例数分别为29例、6例、5例.与CRT术前相比:CRT治疗术后未优化时的左室12节段组织速度达峰时间标准差明显改善[(68.8±26.4)ms与(41.6±23.1)ms,P＜0.01],左室射血分数增加[(28±4)%与(31±3)%,P＜0.05],主动脉瓣前向血流速度时间积分增加[(13.6±3.1)cm与(15.5±4.3)cm,P＜0.05],舒张早期跨二尖瓣血流峰速和舒张早期心肌组织运动峰速的比值下降(13.1±5.3与9.3±4.3,P＜0.05),左室舒张充盈时间延长[(313.2±93.6)ms与(368.6±97.1)ms,P＜0.05].与术后未优化时相比:术后7天优化心脏同步性指标进一步改善(P＜0.05),心功能指标无明显改变;术后3个月、6个月优化与术后7天优化相比,心脏同步性指标无明显改变,P＞0.05;术后6个月优化的左室射血分数增加,左室舒张充盈时间延长,P＜0.01.结论 CRT术后7天,A-V、V-V间期优化治疗改善心脏同步指标;术后6个月优化进一步改善心功能.     

心脏再同步治疗后心室电重构和室性心律失常与左心室逆重构关系探讨

目的 探讨慢性心力衰竭患者心脏再同步治疗（CRT）后心室电重构和室性心律失常与左心室逆重构的关系.方法 入选因心力衰竭于我院行CRT的患者,随访术后即刻与术后6个月体表心电图与超声心动图,记录术后6个月期间窒性心律失常发作次数.根据术后6个月左心室收缩末容积缩小比例（ ΔLVESV）≥15％与否分为有效组与无效组,对比组间QRS时限变化（ΔQRSd）和室性心律失常事件,对左心室逆重构程度与ΔQRSd和室性心律失常事件进行相关性分析,寻找CRT治疗后室性心律失常的预测因素.结果 共入选43例患者,有效组29例,无效组14例,组间基线资料与术后应用药物等差异无统计学意义.全部患者CRT后6个月QRSd无变化（P=0.50）,有效组QRSd明显缩短（P＜0.01）,无效组无变化（P=0.08）.组间ΔQRSd差异有统计学意义（P=0.02）.全部患者CRT后ΔLVESV与△QRSd呈正相关（r=0.523,P＜0.01）.CRT 6个月内室性早搏（PVCs）与室性早搏连发（PVCruns）次数分析显示,log（PVCs）与log（PVC runs）在组间差异有统计学意义（P＜0.01）,log （PVCs）和log.（PVC runs）均与ΔLVESV呈正相关（P＜0.01）.多元回归分析显示,ΔLVESV是log （PVCs）的独立预测因素（β=2.36,P＜0.01）,ΔLVESV和男性是log（ PVC runs）的独立预测因素（β=2.88,P＜0.01;β=-0.74,P=0.03）.结论 CRT后左心室逆重构与电重构及室性心律失常发生减少相关.左心室逆重构程度及性别对CRT患者术后室性心律失常事件有预测意义.     

心脏再同步治疗超反应的预测因子分析

目的 心脏再同步治疗（CRT）能明显改善患者临床症状,逆转心肌重构,称之为CRT超反应.本文主要分析CRT术后,患者超反应的预测因子.方法 采用回顾性研究,2005年1月至2010年6月共有124例随访资料完整的CRT或心脏再同步治疗除颤器（CRT-D）纳入分析,分为超反应组及其他反应组.并在CRT术后第6个月随访时,进行临床评估及超声心动图评价.心功能（NYHA分级）提高≥1级,左心室射血分数（LVEF） ≥0.45或增加2倍以上称为超反应.结果 两组患者在基线状态除QRS时限[（160.2±36.1）ms对（139.6±32.5）ms,P=0.01],完全左束支阻滞比例（95％对82％,P=0.02）、心力衰竭症状出现时间[（21.0±14.6）个月对（36.0±25.3）个月,P=0.02]差异有统计学意义外,其余参数在基线状态差异无统计学意义;有17％的患者出现超反应.6个月随访时超反应组与其他反应组在心功能分级、脑钠肽（BNP）、QRS时限、LVEF及因心力衰竭住院率方面有明显改善.结论 完全左柬支阻滞及心力衰竭症状出现较短的患者CRT反应较好.     

红细胞分布宽度评价心脏再同步化治疗反应性的作用

目的观察心脏再同步化治疗(CRT)的疗效和红细胞分布宽度(RDW)与CRT反应性的关系。方法回顾性分析2007年10月至2016年3月在兰州大学第一医院心脏中心住院的患者45例,依据CRT术后是否有反应分为两组:有反应组(n=27)和无反应组(n=18)。对比分析患者术前及术后6个月随访时的临床资料,采用多因素logistic回归分析CRT反应性的相关因素。结果 CRT治疗后有反应者27例,有反应率为60%。CRT术后两组患者心功能分级间差异具有统计学意义(P0.05)。与治疗前相比,有反应组患者CRT术后的心功能分级、左室射血分数(LVEF)、左室舒张末期内径(LNEDD)、左室舒张末容积(LVEDV)、QRS波群时限(QRSd)、6 min步行距离(6MWD)和明尼苏达生活质量问卷(MLHFQ)均得到显著改善,而无反应组患者CRT术后只有LVEF、LVEDV和QRSd得到显著改善,差异均具有统计学意义(P0.05);组间比较结果显示,CRT术后有反应组患者的心功能分级和LVEF与无反应组差异具有统计学意义(P0.05)。术前心功能分级、QRS≥150 ms、△QRSd、RDW水平和植入心脏再同步化治疗除颤器是CRT后反应性的独立相关因素(P0.05)。结论评估心功能分级、QRS波群和RDW水平是CRT前的重要内容,这对CRT术后的反应性有重要意义。     

应用左心室舒张末容积校正的QRS持续时间对心脏同步化治疗的预测作用

目的探究左心室舒张末容积校正的QRS持续时间(QRSd/LVEDV)对心脏同步化治疗的预测作用。方法2010年1月至2019年1月于解放军总医院选择接受心脏同步化治疗(CRT)的慢性心力衰竭患者79例,在手术前1个月内和术后1年分别进行了心电图和超声心动图检查QRSd和左心室舒张末容积(LVEDV),对上述资料进行单因素及多因素Logistic回归分析。结果CRT应答组患者的QRSd/LVEDV显著高于CRT无应答组[(0.73±0.27)ms/ml比(0.58±0.21)ms/ml,P=0.043];而两组患者的QRSd和LVEDV差异无统计学意义。合并左束支传导阻滞(LBBB)的患者,QRSd/LVEDV与心功能变化显著相关(R=0.469,P=0.032),而在非LBBB患者中,QRSd/LVEDV与心功能变化无显著相关。ROC曲线分析显示,QRSd/LVEDV是CRT应答的重要预测因子(AUC=0.79,P=0.006);多因素回归分析显示,QRSd/LVEDV、LBBB和非缺血性心肌病是CRT应答的独立预测因子。结论QRSd/LVEDV是心力衰竭患者CRT术后应答的独立预测因子。     

心脏再同步化治疗慢性心力衰竭的疗效评价及无效原因分析

目的 评价心脏再同步化治疗(CRT)对慢性心力衰竭患者的临床和超声心动图疗效,总结CRT无效的原因.方法 研究施行CRT的患者53例,男37例,女16例,年龄41～82岁.患者术前均采用血流多普勒和组织多普勒的方法进行收缩不同步的评价,术前和术后6个月进行美国纽约心脏病学会(NYHA)心功能分级评价、心电图和超声心动图检查.临床有效者定义为术后6个月NYHA心功能分级改善1级以上的患者.超声心动图有效者定义为术后6个月左室收缩末容积缩小＞15%或左室射血分数绝对值增加＞5%的患者.结果 CRT术后6个月时,7例患者死亡,46例患者存活.其中NYHA心功能分级至少改善1级者40例,临床有效率为75.5%;超声心动图有效者37例(69.8%).术后6个月:左心室缩小;左室射血分数由(27.4±6.7)%增加到(40.4±10.0)%,P＜0.01;左心房内径缩小;二尖瓣反流减少;肺动脉收缩压由(49.6±13.6)mm Hg(1 mm Hg=0.133 kPa)降低为(38.7±14.5)mm Hg.窦性心律组(42例)的超声有效率显著高于心房颤动组(11例).在窦性心律患者中,与CRT无效组(10例)相比,有效组(32例)起搏前的QRS较宽(P＜0.05),肺动脉收缩压较低(P＜0.05),左室射血前时间较长(P＜0.05);起搏前两组间腔室大小、LVEF、二尖瓣反流面积和组织多普勒的各个收缩不同步参数的差异无统计学意义.结论 CRT能改善心力衰竭患者的左室收缩功能和左室重构,减少二尖瓣反流,降低肺动脉收缩压.窦性心律组的CRT疗效优于心房颤动组.在非缺血性心肌病和左束支传导阻滞患者占多数的研究中,QRS宽度、左室射血前时间和肺动脉收缩压可能预测CRT的疗效.     

心脏再同步化治疗不同病因慢性心力衰竭的临床疗效

目的探讨不同病因慢性心力衰竭病人实施心脏再同步化治疗(CRT)的临床疗效。方法根据心力衰竭病因,将76例实施CRT手术的慢性心力衰竭病人分为缺血性心肌病组(36例)和非缺血性心肌病组(40例),所有病人实施CRT手术后均进行3个月随访,比较两组临床疗效、心功能指标、心脏彩超指标和死亡率。结果 CRT术后3个月,非缺血性心肌病组临床总有效率高于缺血性心肌病组,差异有统计学意义(77.50%与66.67%,P0.05)。CRT术后3个月,两组B型利钠肽(BNP)水平均较手术前降低(P0.05),6 min步行距离均较手术前增加(P0.05),且术后3个月,非缺血性心肌病组BNP水平和6 min步行距离优于缺血性心肌病组(P0.05)。CRT术后3个月,两组左心室射血分数(LVEF)均较手术前增高(P0.05),左心室舒张末期内径(LVEDD)、左心室收缩末期内径(LVESD)、左心房容积(LAV)均较手术前降低(P0.05);且非缺血性心肌病组LVEF高于缺血性心肌病组(P0.05),LVEDD、LVESD和LAV均低于缺血性心肌病组(P0.05)。结论对不同病因慢性心力衰竭病人实施CRT均可取得一定的临床疗效,改善心功能,且非缺血性心肌病病人疗效及心功能改善更明显。     

血清Galectin-3和脑钠肽在心脏再同步化治疗前后的变化及对近期预后的影响

目的:分析我院行心脏再同步化治疗(CRT)前后心力衰竭(心衰)患者血清半乳糖凝集素3(Gal-3)、脑钠肽(BNP)水平变化及其对近期预后的影响。方法:对本院50例心衰患者的随访资料进行分析,随访时间12个月,根据患者是否接受CRT治疗分为CRT组及对照组,采用酶联免疫法(ELISA)检测治疗前及治疗后1、3、6、12个月血清Gal-3和BNP水平,并行超声心动图检查,评估心脏功能。结果:随访至12个月,CRT组和对照组Gal-3水平无明显变化,两组BNP水平均显著下降,且CRT组显著低于对照组(P0.05);CRT组左室舒张末容积(LVEDV)、左室收缩末容积(LVESV)均减小(P0.05),左室射血分数(LVEF)明显升高(P0.05);CRT组患者心衰再入院率显著低于对照组(分别为20%、52%,P=0.019),发生心脏不良事件再入院者基础Gal-3和BNP水平更高。结论:血清Gal-3在心衰患者治疗前后无明显变化,基础Gal-3和BNP水平高者近期预后较差。     

以心室收缩不同步作为心脏再同步化治疗筛选标准的疗效评价

目的:以心室收缩不同步作为心脏再同步化治疗的筛选标准,观察心脏再同步化(cardiac resynchronization therapy,CRT)治疗慢性心力衰竭(CHF)的临床疗效。方法:26例CHF患者经过严格的超声筛选后行CRT,全部患者均经冠状静脉窦植入左心室电极,电极位置尽量与超声提示的左心室收缩最延迟部位一致,术后随访(13.8±10.4)个月。结果:2例患者随访中死亡,其余24例患者治疗后心功能、患者活动度、心率变异性均明显改善(P0.05),左心室舒张末内径从(77.0±9.4)mm缩小至(68.7±10.2)mm(P0.05),左心室内各室壁收缩期达峰时间标准差从(48.4±17.9)ms减少至(30.2±18.6)ms(P0.05)。术后1个月左心室16,12及6节段达最小容积点时间的标准差和最大时间差均有明显减低(P0.05)。结论:CRT是CHF治疗的有效方法,术前应用常规超声心动图及组织多普勒成像技术(TDI)等多项技术来评价患者心室运动的失同步是CRT的有效筛选手段。     

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.