HBsAg、HBcAg活化树突状细胞治疗慢性乙型肝炎的体外研究

目的 研究慢性乙型肝炎患者外周血树突状细胞(DC)经HBsAg、HBcAg活化后的免疫功能.方法 从慢性乙型肝炎患者外周血中培养扩增DC,在DC成熟前,加入纯的HBsAg、HBcAg刺激,用流式细胞仪检测DC表型,用液闪计数仪观察DC对T细胞的增殖作用,用ELISA法检测混合淋巴细胞反应(MLR)中细胞因子的分泌水平.结果 经HBcAg刺激DC的CD86表达率为(92.14±5.12)%,明显高于HBsAg刺激组和未加抗原组(P＜0.01);经HBcAg刺激组DC诱导同种异体静止T细胞增殖的能力每分钟液闪计数值(cpm)为34259±3127,明显高于HBsAg刺激组(20258±2917)和单个核细胞组(3469±417),P＜0.01;经HBcAg刺激组DC MLR中IL-12浓度为(342±42.3)ng/L,分别高于HBsAg刺激组和未加抗原组(P＜0.01).结论 体外经HBcAg刺激DC可有效提呈抗原病毒,并可进一步刺激T细胞产生.     

负载肿瘤抗原的DC体外诱导抗肿瘤免疫反应的实验研究

目的 研究自体及同种异体树突状细胞(DC)体外负载肿瘤抗原后刺激T淋巴细胞增殖及诱导抗肿瘤免疫反应的能力.方法 利用细胞因子诱导人骨髓单个核细胞生成DC,尼龙毛柱法分离T淋巴细胞,3H-TdR掺入法检测负载肺癌细胞凋亡小体的自体及同种异体DC体外刺激T细胞增殖反应,乳酸脱氢酶(LDH)释放法检测负载肺癌细胞凋亡小体的自体及同种异体DC刺激的T细胞对肺癌细胞和乳腺癌细胞系MCF-7的杀伤作用.结果 骨髓细胞诱生的自体及同种异体DC负载肿瘤抗原后,均具有刺激T淋巴细胞增殖的能力,负载肿瘤抗原的自体及异体DC激活的T淋巴细胞后均可杀伤两种靶细胞,T细胞对MCF-7的杀伤力明显低于对患者肺癌细胞的杀伤力. 结论人自体或异体DC体外负载细胞性肿瘤抗原后,可有效地刺激T淋巴细胞的增殖,产生特异性肿瘤杀伤作用.     

慢性乙型肝炎病毒感染产妇的胎儿脐带血树突状细胞的表型及功能

目的探讨孕妇慢性乙型肝炎病毒(HBV)感染对其胎儿脐血的树突状细胞(DC)的表型和功能的影响,并与健康胎儿、健康成人及成人慢性HBV感染者进行对比研究。方法体外分离慢性HBV 感染产妇及健康产妇胎儿脐带血、健康成人及慢性乙型肝炎患者外周血单个核细胞进行树突状细胞转化,行流式细胞术对其表型进行分析,通过交叉混合淋巴细胞培养和DC培养上清液白细胞介素(IL)-12检测来分析DC的功能。结果慢性HBV感染产妇脐血来源DC的CD 80、CD 83的表达显著低于健康胎儿组、健康成人组、成人慢性HBV感染组,CD14的表达则显著高于此三组,P值均<0.0 5;慢性HBV感染产妇脐带血DC分泌的IL-12水平也明显低于健康产妇、健康成人组及慢性乙型肝炎患者(P<0.05);促异体T淋巴细胞增殖能力的强弱依次为健康成人DC-健康脐血T淋巴细胞>健康成人DC-健康成人异体T淋巴细胞>健康脐血DC-异体健康脐血T淋巴细胞>健康脐血DC-健康成人T淋巴细胞>孕母HBV感染脐血DC-健康脐血T淋巴细胞>孕母HBV感染脐血DC-健康异体成人T淋巴细胞。结论慢性HBV感染产妇胎儿脐血DC的成熟和功能显著低于健康胎儿脐血DC、健康成人甚至慢性乙型肝炎患者外周血DC。     

HBV抗原基因修饰树突状细胞疫苗体外抗HBV的作用

目的：探讨腺病毒载体介导HBV抗原基因修饰的树突状细胞(DCs)诱导抗HBV特异性CTL反应方法：制备携带HBsAg、HBeAg和HBcAg基因的3种重组腺病毒Ad-HBs,Ad-HBe,Ad- HBc,分别转染自脐带血体外诱导培养的DCs,观察腺病毒转染DCs效率和DCs中HBV抗原的表达;混合淋巴细胞反应(MLR)测定HBV抗原基因修饰DCs刺激同种异体T淋巴细胞增殖能力;乳酸脱氢酶释放法检测特异性CTL细胞对HepG_222．1．5靶细胞的杀伤能力．结果：腺病毒载体能够高效介导HBV三个抗原基因在DCs中表达,90%以上DCs表达示踪基因EGFP,且DCs细胞形态完整：感染后72 h HBsAg和HBeAg含量分别为0．919和0．328(吸光度A值)．MLR实验显示,HBV抗原基因修饰DCs仍然具有刺激同种异体T细胞的增殖能力,Ad-HBs转染DCs组、Ad-HBe转染DCs组、Ad-HBc转染DCs组和未转染DCs组之间刺激T细胞的增殖水平无明显差异(F=1．194,P=0．389);在E：T比例为2：1,10：1和25：1时,Ad-HBs转染DC组、Ad-HBe转染DCs组和Ad-HBc转染DCs组对HepG_222．1．5细胞的杀伤率均明显高于未转染DCs组(P＜0．001);以Ad- HBc转染DC组对HepG_222．1．5细胞杀伤率最高．结论：HBV抗原基因修饰DCs疫苗具有刺激同种异体T细胞增殖能力,同时能增强抗HBV特异性CTL反应的能力,可能发展为一种新型抗病毒疫苗．     

树突状细胞激活的肿瘤浸润性淋巴细胞抗胃癌活性的研究

目的　树突状细胞 (DC)是目前已知的功能最强的抗原提呈细胞 (APC) ,可以向包括肿瘤浸润性淋巴细胞 (TIL)在内的T淋巴细胞提呈抗原 ,并诱发细胞毒T淋巴细胞 (CTL)反应。该文探讨树突状细胞激活的肿瘤浸润性淋巴细胞体外对胃癌细胞 (SGC 790 1 )的杀伤活性。方法　从胃癌患者外周血获取DC ,应用粒 /巨噬细胞集落刺激因子 (GM CSF)、白介素 4(IL 4)和肿瘤抗原激活DC ,然后用DC激活TIL ,观察TIL在体外对自体胃癌细胞和人胃癌细胞株细胞的杀伤活性。结果　DC激活的TIL具有很高的对自体胃癌细胞杀伤活性 ,杀伤率为 (89.39± 3 .0 5) % ,明显高于未经DC激活的TIL、CD激活的T淋巴细胞和未经DC激活的T淋巴细胞对自体胃癌细胞的杀伤率 [杀伤率分别为 (54 .37±1 .50 ) % ,(53 .92± 1 .46) %和 (3 .55± 0 .2 5) % ]。而它们对SGC 790 1细胞的杀伤活性则相对较低。结论　胃癌患者外周血DC能诱导TIL产生高效而特异的抗胃癌免疫     

负载HBcAg对慢性HBV感染患者树突状细胞的活化作用及功能影响

目的:探讨免疫耐受期慢性乙型肝炎(CHB)患者外周血树突状细胞(DC)负载HBcAg后细胞表型及免疫功能的改变。方法:从CHB免疫耐受期患者外周血分离培养DC,在DC成熟前,加入重组HBcAg表位肽,诱导HBV特异性DC分化成熟,流式细胞仪检测DC表面共刺激分子CD1a、CD80、CD83的表达水平,应用淋巴细胞增殖试验评估DC功能。结果:负载不同剂量的HBcAg后,DC细胞活化增强,DC细胞共刺激分子标志物CD1a、CD80以及CD83表达率均明显上升,且随着抗原负载剂量的增加,表达率进一步增加,各组之间差异具有统计学意义(均P<0.001);未负载HBcAg的DC细胞激活的淋巴细胞反应较弱,负载HBcAg的DC细胞刺激同种异体健康成人T淋巴细胞增殖能力增强,且随着负载抗原剂量的加大,T淋巴细胞的增殖能力进一步提高,与未负载抗原的对照组相比,差异具有统计学意义(F=428.14,P=0.000)。结论:体外负载HBcAg刺激CHB患者DC细胞可增强其有效抗原提呈能力,促进T淋巴细胞增殖。     

乙型肝炎病毒在造血干细胞内复制及对其免疫活性的影响

目的 研究不同载量HBV感染脐血来源的CD34~+造血干细胞(HSC)的一般规律,以及探讨HBV感染HSC后诱生的树突状细胞(DC)的功能状态.方法 无菌条件下采集脐血,磁珠分离仪分离纯化CD34~+ HSC.把CD34~+ HSC分为HBV感染组及对照组,用免疫组织化学及原位杂交方法检测HSC内病毒感染情况.分3组将HSC接种于24孔板连续培养12 d,各组分别加入细胞因子组合及不同病毒载量HBV(A组1×10~7拷贝/mL,,B组1×10~5拷贝/mL,C组1×10~3拷贝/mL)的血清,于培养的0、1、6、12 d检测各组细胞数,上清液及细胞中HBV DNA拷贝数.用两步法诱生的DC作为刺激细胞,以异基因健康者外周血T淋巴细胞作为反应细胞,噻唑蓝比色法检测DC对同种异体T淋巴细胞的刺激增殖作用.组间比较采用t检验.结果 免疫组织化学检测结果显示,HBV感染12 d的HSC中可检测到HBsAg的表达,而未感染的HSC中无HBsAg阳性细胞.原位杂交检测结果显示,HBV感染12 d的HSC中可检测到HBV DNA,未感染的HSC中无阳性细胞.C组第1天的细胞增殖与A、B组比较无明显差异,第6、12天细胞增殖高于A、B组,且第6天的细胞计数差异有统计学意义(t=5.125,t=6.327;均P<0.05).在第12天A组细胞内可检出1×10~6拷贝/mL HBV DNA,B组可检出1×10~3拷贝/mL,C组则12 d内均不能检出.上清液检出情况与细胞内相符.混合淋巴细胞反应显示HBV感染组诱生的DC对同种异体T淋巴细胞刺激增殖作用明显低于对照组,且差异有统计学意义(在DC与T淋巴细胞的比例达到0.05时,t=3.156,P<0.05;在比例达到0.1、0.5时,t=4.873,t=5.103,均P<0.01).结论 HBV可以在CD34~+ HSC内复制并随HSC扩增而同步增加.HBV感染的HSC诱生的DC对同种异体T淋巴细胞刺激增殖能力减低,即HBV感染HSC后其分化的免疫细胞的生物活性降低.     

冠状动脉支架术后C反应蛋白升高与树突状细胞的关系

目的 :研究冠状动脉支架术后高敏C反应蛋白 (hsCRP)的升高与树突状细胞 (DC)的关系。方法 :术前及术后 2d分离 11例冠状动脉支架术患者外周血单个核细胞 (PBMC) ,在含粒细胞巨噬细胞集落刺激因子(GM CSF)和白细胞介素 4 (IL 4 )的培养条件下制备DC。用流式细胞仪检测DC表面共刺激分子CD86 (B7 2 )的表达 ;混合淋巴细胞反应 (MLR)检测DC对同种异体T淋巴细胞的刺激能力 ;ELISA法测定MLR上清液中的细胞因子 ;比浊法测定hsCRP浓度 ,并探讨CD86表达与hsCRP的相关性。结果 :与术前比较 ,术后 2dDC表面CD86的表达明显增高 ;对T淋巴细胞刺激的能力增强 ;经DC刺激的淋巴细胞分泌促炎细胞因子 (IL 1β、IL 6、TNF α)增多 ,抑炎细胞因子 (IL 10 )减少 ;同时血hsCRP升高 ,且CD86的表达与血hsCRP水平正相关。结论 :支架术后DC的功能被激活 ,由此启动的T淋巴细胞的增殖和炎性反应可能是术后hsCRP升高的原因     

恩替卡韦对慢性乙型肝炎患者树突状细胞功能的体外影响

目的:研究恩替卡韦(ETV)对慢性乙型肝炎(CHB)患者外周血树突状细胞(dendritic cell,DC)功能的影响.方法:体外常规分离CHB患者及健康人外周血单个核细胞,诱导扩增后常规培养.第4天将其与一定浓度的恩替卡韦共培养,第8天收获DC进行细胞表型、同种异体混合淋巴细胞反应等相关检测.结果:细胞培养8 d时DC形态分化健康对照组优于CHB ETV处理组,CHB ETV处理组优于CHB组;CHB组CD1a(35.73±3.12 vs 62.31±5.22,P<0.01),CD80(28.19±1.64 vs 45.38±3.10,P<0.01),CD83(22.24±2.14 vs 40.63±7.21,P<0.01)及HLA-DR(36.74±0.98 vs 56.05±3.89,P<0.01)表达明显低于健康对照组,而ETV处理组与CHB组相比CD83 (27.41±9.23 vs 22.24±2.14,P<0.05),CD80(32.67±7.82 vs 28.19±1.64,P<0.05)及HLA-DR(40.84±5.57 vs 36.74±0.98,P<0.01)显著高表达;淋巴细胞增殖能力测定ETV处理组DC刺激同种异体T淋巴细胞增殖能力较CHB组增强(1.53±0.09 vs 1.45±0.12,P<0.05).结论:恩替卡韦作为治疗CHB的新一代核苷类药物,除了直接抑制乙肝病毒DNA合成外,也能够增强CHB患者外周血DC的功能,通过调节机体的免疫系统发挥间接抗病毒作用.     

同种异体反应中分泌细胞因子T淋巴细胞的测定及其临床初探

目的　测定同种异体反应中分泌细胞因子的T淋巴细胞水平并初步探讨其临床意义。方法　利用细胞因子分泌检测方法 (CKSA)从单细胞水平定量测定人混合淋巴细胞反应中分泌γ干扰素 (IFNγ) ,白细胞介素 4 (IL 4 )和IL 10的T细胞 ;分析 2例患者外周血分泌IFNγ的T细胞和急性移植物抗宿主病 (aGVHD)的关系。结果　经同种异体外周血单个核细胞 (PBMNC)刺激后分泌IFNγ的T细胞水平 (1 12± 0 13) %明显高于对照组 (0 2 3± 0 0 7) % ,P <0 0 1。而分泌IL 4和IL 10的T淋巴细胞则无升高 ,分别为 (0 12± 0 0 3) %、(0 10± 0 0 3) % ,P >0 0 5。 2例患者外周血分泌IFNγ的T细胞水平和aGVHD有一定的相关性。结论　利用CKSA测定同种异体PBMNC刺激后分泌IFNγ的T细胞水平显著升高 ,提示具有临床应用价值     

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.