老年冠心病患者PCI术后氯吡格雷抵抗与CYP2C19基因多态性的关系研究

目的 探索老年冠心病患者PCI术后氯吡格雷抵抗与CYP2C19基因多态性的关系。方法 选取PCI治疗术后服用氯吡格雷的老年冠心病患者 99例,应用血栓弹力图检测其ADP 诱导的血小板抑制率,根据结果分为氯吡格雷抵抗组（CR组）和非氯吡格雷抵抗组（NCR组）,同时检测其 CYP2C19 基因多态性;分析比较两组患者之间一般临床资料、生化指标及CYP2C19基因型的差异,不同基因型之间血小板抑制率的差异,以及多因素logistic回归分析氯吡格雷抵抗的危险因素。结果 99 例老年冠心病患者中,CR组35例,NCR组64例;两组之间的CYP2C19基因型的差异（CR组CYP2C19快代谢型6例,弱代谢型29例,NCR组快代谢型42例,弱代谢型22例）、总胆固醇（TC）水平（5.43±0.32mmol/L vs 5.24±0.50mmol/L）、低密度脂蛋白胆固醇（LDL-C）水平（3.43±0.35mmol/L vs 3.20±0.49mmol/L）、高密度脂蛋白胆固醇（HDL-C）水平（1.00±0.22mmol/L vs 1.11±0.20mmol/L）有统计学差异（P<0.05）。在老年患者中CYP2C19快代谢型和弱代谢型的人群分布为48.48%和51.52%（其中中间代谢型为45.46%,慢代谢型为6.06%）,快代谢型和弱代谢型患者的血小板抑制率分别为78.43±18.22%、42.65±11.55%;差异有统计学意义（P<0.05）。全变量二元logistic回归分析结果显示CYP2C19弱代谢基因型为老年冠心病患者发生氯吡格雷抵抗的独立危险因素（P<0.05）。结论 携带CYP2C19弱代谢基因型是导致老年冠心病患者氯吡格雷抵抗的独立危险因素,对老年冠心病患者行CYP2C19基因多态性检测有助于指导PCI术后的抗血小板治疗。     

CYP2C19指导ACS行PCI患者抗血小板药物选择的研究

目的:根据急性冠状动脉综合征(ACS)行经皮冠状动脉介入治疗(PCI)患者CYP2C19基因型的不同选择抗血小板药物及剂量进行治疗,观察其抗血小板效应及出血风险,为个体化抗血小板药物的选择提供参考。方法:入选231例行PCI的ACS患者并检测其CYP2C19基因型,根据基因型的不同分为快代谢组(CYP2C19*1/*1)、中代谢组(CYP2C19*1/*2、CYP2C19*1/*3)、慢代谢组(CYP2C19*2/*2、CYP2C19*3/*3、CYP2C19*2/*3),并分别给予快代谢组常规双联抗血小板治疗(氯吡格雷75mg qd+阿司匹林100mg qn),中代谢组氯吡格雷剂量加倍(氯吡格雷150mg qd+阿司匹林100mg qn),慢代谢组换用新型抗血小板药物(替格瑞洛90mg bid+阿司匹林100mg qn),比较各组用药3个月后血小板抑制率变化情况及出血事件的发生情况。结果:根据基因型所分3组的临床基线资料及PCI结果无统计学差异。中代谢组及慢代谢组患者用药3个月后,血小板抑制率均较快代谢组血小板抑制率升高,慢代谢组血小板抑制率较中代谢组明显升高,差别具有统计学意义(均P0.05)。结论:PCI术后的ACS患者中,携带CYP2C19*2、CYP2C19*3等位基因的高危患者,采用氯吡格雷剂量加倍及换用替格瑞洛均可充分抑制血小板,且换用替格瑞洛优于氯吡格雷剂量加倍。     

CYP2C19基因多态性对PCI术后抗血小板治疗的指导作用

目的:探讨CYP2C19基因多态性对经皮冠状动脉介入(PCI)术后抗血小板治疗的指导作用。方法:选择PCI术后服用氯吡格雷的冠心病患者105例,检测其CYP2C19基因多态性,并根据结果分为正常代谢组(51例,快代谢型)和弱代谢组(54例,中间代谢型和慢代谢型)。分析比较两组血栓弹力图(TEG)测得的二磷酸腺苷(ADP)诱导的血小板抑制率以及氯吡格雷抵抗(CR)率。结果:105例患者中,正常代谢组和弱代谢组的人群分别占48.57%和51.43%(在弱代谢组中,中间代谢型为43.81%,慢代谢型为7.62%)。与正常代谢组比较,弱代谢组ADP诱导的血小板抑制率[(78.14±17.86)%比(41.67±12.05)%]显著降低,CR发生率(11.76%比59.26%)显著升高(P均=0.001)。结论:CYP2C19基因多态性是氯吡格雷抵抗的重要影响因素,正常代谢组患者PCI术后服用氯吡格雷的疗效显著优于弱代谢组,故对患者行CYP2C19基因多态性检测有助于指导PCI术后的抗血小板治疗。     

CYP2C19基因多态性与PCI手术患者血小板抑制率的相关性研究

目的 研究CYP2C19基因多态性对经皮冠状动脉介入治疗（PCI）手术患者血小板抑制率的影响。方法 本研究纳入符合入选标准的2014年1月至2016年4月在解放军第一七五医院心内科住院的冠心病患者210例,均需行PCI手术治疗。所有入选者均采取静脉血标本并提取外周血基因组DNA,进行PCR 扩增及纯化,进行基因芯片杂交显色,通过生物芯片识读仪检测CYP2C19基因型,根据不同的基因型对患者进行分组。入选者服用负荷量阿司匹林+氯吡格雷24 h后采取静脉血标本,然后用血栓弹力图仪（TEG）检测并自动计算出二磷酸腺苷（ADP）诱导的血小板抑制率。结果 入选的210例患者各基因型比例分别为：（*1/*1）94例（44.8%)、（*1/*2）79例（37.6%）、（*1/*3）12例（5.7%）、（*2/*2）20例（9.5%）、（*2/*3）4例（1.9%）、（*3/*3）1例（0.5%）,其中快代谢型（EM型）94例（44.8%）、中等代谢型（IM型）91例（43.3%）、慢代谢型（PM型）25例（11.9%）,共有43例患者（20.5%）出现氯吡格雷抵抗现象（CR）。不同基因型组患者的血小板抑制率差异均有统计学意义（P<0.01）,其中PM型患者的血小板抑制率最低,IM型次之;不同基因型组患者的氯吡格雷抵抗情况差异有统计学意义（P<0.01）,其中PM型患者的CR远高于另外两组。结论 CYP2C19不同基因型对氯吡格雷抗血小板作用的影响存在显著差异,其中携带CYP2C19 *2或*3突变等位基因的PCI手术患者发生CR的风险明显增加。     

急性冠状动脉综合征合并2型糖尿病患者冠状动脉介入术后替格瑞洛与氯吡格雷抗血小板疗效及预后

目的应用血栓弹力图(TEG)评价替格瑞洛与氯吡格雷在急性冠状动脉综合征(ACS)合并糖尿病患者经皮冠状动脉介入治疗(PCI)后抗血小板的疗效及预后。方法纳入ACS合并糖尿病行PCI术的患者180例。随机分为两组,氯吡格雷组(n=92)术前接受负荷量阿司匹林300 mg+氯吡格雷300 mg,术后给予阿司匹林100mg/d,氯吡格雷75 mg/d;替格瑞洛组(n=88)术前接受负荷量阿司匹林300 mg+替格瑞洛180 mg,术后给予阿司匹林100 mg/d,替格瑞洛90 mg,每天两次。血栓弹力图检测两组患者PCI术后24 h花生四烯酸(AA)诱导的血小板抑制率和二磷酸腺苷(ADP)诱导的血小板抑制率,观察并比较两组3个月内不良心血管事件及出血等安全性事件。结果替格瑞洛组ADP激活血小板形成最大血凝块强度(MA-ADP),低于氯吡格雷组(34.94%±11.91%比47.16%±14.90%,P0.001)。血小板AA抑制率、ADP抑制率替格瑞洛组明显高于氯吡格雷组(68.24%±22.96%比48.21%±32.91%,58.16%±23.52%比33.34%±26.67%,P0.001)。结论 ACS合并2型糖尿病患者中,替格瑞洛抗血小板聚集的效果明显优于氯吡格雷,可显著降低3个月内心血管终点事件的发生率,不增加出血风险。     

冠心病介入治疗术后服用氯吡格雷患者的CYP2C19基因型与血小板抑制率的关系研究

目的探讨服用氯吡格雷的冠心病介入术后患者的CYP2C19基因型与二磷酸腺苷(ADP)诱导的血小板抑制率之间的关系。方法选取冠心病介入治疗术后服用氯吡格雷的患者500例,根据CYP2C19基因型分为氯吡格雷快、中、慢代谢3组,通过血栓弹力图测定ADP诱导的血小板抑制率;分析3组CYP2C19基因型与血小板抑制率之间的相关性;对患者进行术后6个月的随访,观察心血管不良事件发生率。结果 (1)500例患者中,氯吡格雷快、中、慢代谢3组的人群分布为42.0%、44.8%和13.2%。(2)氯吡格雷快代谢组的血小板抑制率在0~20%、20%~50%、50%~75%和75%~100%的人群分布为1.90%、14.29%、30.00%和53.81%;中代谢组的人群分布为3.57%、17.86%、22.32%和56.25%;慢代谢组的人群分布为7.58%、21.21%、30.30%和40.91%;3组之间ADP诱导的血小板抑制率差异无统计学意义(P>0.05)。(3)随访6个月,氯吡格雷快、中、慢代谢3组发生心血管缺血事件分别有9、13和4例,3组之间的缺血性心血管事件差异无统计学意义(P>0.05)。结论在本组人群中,CYP2C19基因型与氯吡格雷血小板抑制率之间无明显相关性,推测仅通过CYP2C19基因型不能准确预测氯吡格雷抵抗。     

血栓弹力图评价经PCI术后氯吡格雷及阿司匹林血小板抑制情况及作用机制

目的探讨血栓弹力图(TEG)监测经皮冠状动脉介入治疗(PCI)患者服用氯吡格雷和阿司匹林药物后TEG参数情况及血小板的抑制效果。方法选取135例老年冠心病患者,随机分为氯吡格雷组、阿司匹林组和氯吡格雷联合阿司匹林(联合用药)组。采用TEG仪监测分析花生四烯酸(AA)和二磷酸腺苷(ADP)途径诱导的血小板抑制率,并分析3组血小板抑制率的差异性。结果治疗后3组反应时间(R)、凝固时间(K)均升高,凝固角(α)、最大振幅(MA)均降低,联合用药组R、K高于氯吡格雷、阿司匹林组,α、MA低于氯吡格雷、阿司匹林组,差异有统计学意义(P0.05)。TEG检测结果发现阿司匹林组AA途径诱导和氯吡格雷组ADP途径诱导的血小板抑制率差异无统计学意义(P0.05);联合用药组AA、ADP途径血小板抑制有效率大于氯吡格雷组、阿司匹林组,差异有统计学意义(P0.05)。结论联合服用阿司匹林和氯吡格雷相较于单独使用药物具有更好的抗血小板作用。TEG能够敏感检测不同药物对抗血小板治疗的指标影响,进而调整治疗方案。     

血栓弹力图对大面积脑梗死不同剂量抗血小板聚集药物疗效的评估价值

目的应用血栓弹力图(TEG)评估大面积脑梗死急性期患者高、低剂量阿司匹林联用氯吡格雷对血小板抑制率的影响。方法回顾性纳入北华大学附属医院接诊的急性大面积脑梗死患者,并按阿司匹林口服剂量的不同分为低剂量组(阿司匹林100 mg+氯吡格雷75 mg)52例和高剂量组(阿司匹林300 mg+氯吡格雷75 mg)62例。两组患者均于入院后开始服用阿司匹林及氯吡格雷,于服药第4天,采用TEG检测患者花生四烯酸(AA)途径血小板抑制率和二磷酸腺苷(ADP)途径血小板抑制率。比较两组患者血小板抑制情况及药物抵抗的发生情况。结果低剂量组AA抑制率及ADP抑制率与高剂量组均无统计学差异(均P>0.05)。低剂量组发生阿司匹林抵抗及氯吡格雷抵抗与高剂量组无统计学差异(均P>0.05)。低剂量组脑梗死出血转化发生率与高剂量组无统计学差异(P>0.05)。结论对大面积脑梗死患者,TEG评价的低剂量与高剂量抗血小板聚集治疗对血小板抑制效果无明显差异。     

血栓弹力图在急性脑梗死患者抗血小板治疗效果评价中的应用

目的探讨采用血栓弹力图(TEG)评价阿司匹林和氯吡格雷治疗急性脑梗死患者的抗血小板效果,以指导对急性脑梗死患者抗血小板聚集药物治疗的个体化调整。方法选择急性脑梗死患者82例,予阿司匹林100 mg和氯吡格雷75 mg联合治疗7 d后,采用TEG仪检测花生四烯酸(AA)途径诱导的血小板抑制率和腺苷二酸(ADP)受体途径诱导的血小板抑制率,比较患者经两种途径诱导的血小板抑制率以及患者对阿司匹林和氯吡格雷治疗反应的差异。同时选择急性脑梗死患者40例作为对照组,单用阿司匹林100 mg抗血小板治疗7d,对比两组TEG参数(R值、K值、angle角、MA值)。结果急性脑梗死予阿司匹林、氯吡格雷双抗血小板,阿司匹林对AA途径的抑制率明显高于氯吡格雷对ADP受体途径的抑制率,差异有统计学意义(P0.01);对阿司匹林反应良好的患者,4例对氯吡格雷无反应,15例反应低下;对氯吡格雷反应良好的患者,仅1例对阿司匹林反应低下。对氯吡格雷反应低下者,3例对阿司匹林无反应,5例低下,6例对阿司匹林有效,15例良好。两种疗效有一定关联性(P0.01)。对阿司匹林反应良好+有效为62例,反应低下+无效者20例;氯吡格雷反应良好+有效者42例;反应低下+无效者38例,两种药物疗效差异有统计学意义(P0.01)。单用阿司匹林组与双联抗血小板组比较两组患者R值、K值、α角、MA值均无明显差别(P0.05)。结论采用TEG仪检测对急性脑梗死患者抗血小板治疗的疗效评价有较高的临床价值。双联抗血小板中阿司匹林对急性脑梗死患者血小板聚集的抑制作用强于氯吡格雷。患者对阿司匹林和氯吡格雷治疗的反应有差异性,部分对氯吡格雷反应低下者,可能对阿司匹林反应良好或有效。双联抗血小板治疗对血凝的影响较单用阿司匹林无明显差别。     

血栓弹力图评估经皮介入治疗后患者抗血小板药物抵抗发生情况及影响因素

目的探讨行经皮介入治疗(percutaneous coronary intervention PCI)后口服阿司匹林联合氯吡格雷双联抗血小板用药患者,经血栓弹力图(thrombelastography TEG)测得血小板抑制率等提示阿司匹林、氯吡格雷抵抗的发生率,分析其影响因素。方法 2012年08月—2015年08月期间,行PCI患者280例,TEG测得二磷酸腺苷通道血凝块最大强度(MAADP)、花生四烯酸(AA)和二磷酸腺苷(ADP)诱导的血小板抑制率等相关数据,以AA诱导血小板抑制率50%为阿司匹林抵抗,ADP诱导的血小板抑制率30%为氯吡格雷抵抗。收集临床及实验资料进行分析。结果全部患者中,阿司匹林抵抗(aspirin resistance)为82例,氯吡格雷抵抗(clopidogrel resistance)88例,发生率为29.3%、31.4%。年龄、吸烟、合并高血压、糖尿病等未影响抗血小板药物抵抗发生。合并用药方面,泮托拉唑未对抗血小板药物抵抗产生影响,使用两种他汀对抗血小板药物反应相似。结论 TEG检测阿司匹林、氯吡格雷抵抗发生率较高,一般临床因素及合并用药对其影响不明确,但应引起临床注意。     

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.     

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.     

Serological survey of HIV and syphilis in pregnant women in Madagascar

Objectives Peripartal transmission of human immunodeficiency virus (HIV) and Treponema pallidum, the causative agent of syphilis, leads to severe consequences for newborns. Preventive measures require awareness of the maternal infection. Although HIV and syphilis testing in Madagascar could be theoretically carried out within the framework of the national pregnancy follow‐up scheme, the required test kits are rarely available at peripheral health centres. In this study, we screened blood samples of pregnant Madagascan women for HIV and syphilis seroprevalence to estimate the demand for systemic screening in pregnancy. Methods Retrospective anonymous serological analysis for HIV and syphilis was performed in plasma samples from 1232 pregnant women that were taken between May and July 2010 in Ambositra, Ifanadiana, Manakara, Mananjary, Moramanga and Tsiroanomandidy (Madagascar) during pregnancy follow‐up. Screening was based on Treponema pallidum haemagglutination tests for syphilis and rapid tests for HIV, with confirmation of positive screening results on line assays. Results Out of 1232 pregnant women, none were seropositive for HIV and 37 (3%) were seropositive for Treponema pallidum. Conclusions Our findings are in line with previous studies that describe considerable syphilis prevalence in the rural Madagascan population. The results suggest a need for screening to prevent peripartal Treponema pallidum transmission, while HIV is still rare. If they are known, Treponema pallidum infections can be easily, safely and inexpensively treated even in pregnancy to reduce the risk of transmission.     

Variabilité des concentrations plasmatiques de l’angiotensinogène et risque d’hypertension artérielle chez le rat transgénique

Aim

Genetic polymorphisms of the human angiotensinogen gene are frequent and may induce up to 30% increase of plasma angiotensinogen concentrations with a blood pressure increase of up to 5 mmHg. Their role for the pathogenesis of human arterial hypertension remains unclear. High plasma angiotensinogen levels could increase the sensitivity to other blood pressure stressors.

Methods

Male transgenic rats with a 9-fold increase of plasma angiotensinogen concentrations and male non-transgenic rats aged 10 weeks were treated or not with NG-Nitro-L-arginine-methyl ester for 3 weeks in their drinking water (n = 3/group). Systolic blood pressure and body weight were measured at baseline and at the end of the study when left ventricular weight and ventricular expression of angiotensin I-converting enzyme and procollagen Iα1 were determined (polymerase chain reaction).

Results

At baseline, transgenic rats had +18 mmHg higher bood pressure and –8% lower body weight compared to non-transgenic rats (P < 0.05) without significant changes for the vehicle groups throughout the study (P > 0.05). NG-Nitro-L-arginine-methyl ester increased blood pressure, left ventricular weight and left ventricular weight indexed for body weight by +41%, +17.6% and +18.6% (P < 0.05) in transgenic and +25%, +5.3% and +6.7% (P > 0.05) in non-transgenic rats compared to untreated animals, respectively. Cardiac gene expression showed no differences between groups (P > 0.05).

Conclusion

Increased plasma angiotensinogen levels may sensitize to additional blood pressure stressors. Our preliminary results point towards an independent role of angiotensinogen in the pathogenesis of human hypertension and associated end-organ damage.     

Morphological and immunocytochemical heterogeneity of cultured pinealocytes from one-week-and two-month-old rats: Planimetric and densitometric investigations

Abstract: In vitro preparations of rat pinealocytes are widely used for biochemical analyses of signal transduction processes. This paper deals with morphological and immunocytochemical features of such preparations. Special attention was paid to the problems of whether pinealocytes represent a heterogeneous cell population and how such heterogeneity may develop during ontogeny. The investigations were performed with cells which were obtained from the pineal organ of one-week-and two-month-old rats, attached to synthetic peptide-coated coverslips or tissue culture chamber slides, and maintained under in vitro conditions overnight. The attached cells were then fixed with paraformaldehyde. These preparations yielded monolayers of spherical cells of different sizes; most cells were isolated, but some of them were aggregated and formed small clusters. On the average, the cells from the one-week-old animals were smaller than the cells from the two-month-old animals. Immunocytochemical demonstration of S-antigen, a pinealocyte-specific marker, showed that the majority of the cells from two-month-old animals were intensely or moderately labelled. Pinealocytes from one-week-old animals were less S-antigen immunoreactive. Only very few cells (less than 1% displayed glial fibrillary acidic protein (GFAP)-immunoreactivity. Planimetric investigations of the cell size and semiquantitative densitometric investigations of the intensity of the S-antigen immunoreaction revealed that (i) pinealocytes kept in vitro form a heterogeneous cell population, and that (ii) this heterogeneity increases during postnatal development from one-week-old to two-month-old animals. Two groups of pinealocytes can be distinguished based on their developmental fate: pinealocytes of one group grow dramatically, but show only a moderate increase in S-antigen immunoreactivity, and pinealocytes of the other group retain their size, but display a distinct increment in S-antigen immunoreacti vitv.     

Effects of pinealectomy and melatonin administration on certain indices of ovarian hyperplasia and/or hypertrophy in rats with both ovaries intact or after unilateral ovariectomy

Abstract: In earlier studies from other laboratories it was shown that melatonin decreased ovarian weight in rats and inhibited compensatory hypertrophy of the remaining ovary after unilateral ovariectomy. This study was designed to examine the influence of melatonin on certain indices of ovarian hyperplasia and/or hypertrophy in adult female rats with both ovaries preserved and with either an intact pineal gland or with the pineal gland removed (pinealectomy, PX) or, finally, in sham-PX animals. Similar studies were conducted on rats after unilateral ovariectomy, referring the examined parameters to the remaining intact ovary. The studies included mitotic activity of granulosa layer cells and corpus luteum cells, ovarian weight, ovarian cross-sectional area, cross-sectional area of the granulosa layer of all the Graafian follicles and the cross-sectional areas of the corpora lutea, visible on the ovarian cross-section. On the basis of results, we conclude that: 1) the effect of PX on the processes of ovarian hyperplasia and hypertrophy may vary; analogously, exogenous melatonin administration may influence ovarian hyperplasia and hypertrophy in different ways; 2) PX and exogenous melatonin may, under certain conditions, exert similar biological effects, even synergistic effects; 3) melatonin inhibits ovarian growth processes, while the effects of PX are variable; 4) the results indicate that in experiments performed on rats, with the use of two control groups, i.e., intact and sham-PX, melatonin effects on these two groups may differ.