雌性大鼠老化过程中脾细胞雌激素受体含量及白细胞介素—2 …

目的 探讨雌性大鼠老化过程中血清雌激素浓度、脾细胞雌激素受体（ＥＲ）含量及白细胞介素－２（ＩＬ－２）、肿瘤坏死因子（ＴＮＦ）活性变化的相关性。方法 以各月龄组雌性大鼠为研究对象，应用放射免疫法、放射配体结合分析法、ＭＴＴ法及细胞毒法等技术，观察上述各指标随老化的变化。结果 随着老化雌性大鼠血清Ｅ２浓度与脾细胞ＥＲ含量及脾细胞诱生ＩＬ－２、ＴＮＦ活性均明显下降，并呈明显正相关。结论 生理水平血Ｅ２对     

消化系恶性肿瘤患者血清与腹水中细胞因子活性变化

目的研究消化系恶性肿瘤（ＤＭＴ）患者血清与腹水中内源性ＩＬ２,ＩＬ６,ＩＬ８,ＴＮＦα和ＩＦＮγ的生物学活性．方法应用ＥＬＩＳＡ法检测了１５例ＤＭＴ患者（肝癌１１例,胆总管癌１例,胰腺癌１例,胃癌１例,直肠癌１例）血清与腹水中５种细胞因子活性,并与６例肝硬变（ＬＣ）患者和８例正常成人进行了比较分析．结果ＤＭＴ患者血清ＩＬ２,ＩＬ６的生物学活性显著低于ＬＣ（Ｐ＜００５）;腹水中ＩＬ２,ＩＬ８活性显著低于ＬＣ组（Ｐ＜００１）,而ＩＬ６和ＩＦＮγ活性则高于ＬＣ组（Ｐ＜００１,００５）．ＤＭＴ患者血清中ＩＬ６,ＩＬ８活性明显高于正常成人组（Ｐ＜００５）;ＩＬ２,ＩＦＮγ则低于正常成人组,但缺乏显著性．肝癌血清和腹水中ＩＬ２活性显著高于非肝癌组（Ｐ＜００５）;而ＩＬ６活性则相对降低（Ｐ＜００５）．结论恶性肿瘤患者血清中ＩＬ２和ＩＦＮγ活性低于正常人,是ＤＭＴ患者抗肿瘤免疫功能缺陷的标志．ＩＬ６对于预测ＤＭＴ患者的预后具有重要的意义     

肿瘤坏死因子对鼠甲状腺细胞钙离子的作用

目的　观察 Ｔ Ｎ Ｆα对甲状腺细胞肌醇脂质／ 钙离子（ Ｉｎｓ／ Ｃａ２ ＋ ） 系统的作用。方法　利用激光扫描共聚焦显微镜（ Ｌ Ｓ Ｃ Ｍ） 观察 Ｔ Ｎ Ｆα对鼠甲状腺 Ｆ Ｒ Ｔ Ｌ５ 细胞内 Ｃａ２ ＋ 的影响。实验前细胞以不含 Ｔ Ｓ Ｈ 的５ Ｈ（５ 种激素） 培养液培养３ 天，将待测细胞以 Ｆｌｕｏ３ 负载，分别加入不同浓度的 Ｔ Ｎ Ｆα，以 Ｌ Ｓ Ｃ Ｍ 扫描（４８８ｎｍ ） 测定细胞内 Ｃａ２ ＋ ，观察 Ｔ Ｎ Ｆα的作用。结果　１ ． Ｔ Ｎ Ｆα可降低 Ｆ Ｒ Ｔ Ｌ５ 细胞内基础的 Ｃａ２ ＋ 水平，其效应随 Ｔ Ｎ Ｆα浓度的增加而增强。２ ． Ｔ Ｎ Ｆα可抑制 Ｔ Ｓ Ｈ 刺激甲状腺 Ｆ Ｒ Ｔ Ｌ５ 细胞 Ｃａ２ ＋ 升高的效应。结论　 Ｔ Ｎ Ｆα可以通过抑制甲状腺细胞 Ｉｎｓ／ Ｃａ２ ＋ 系统发挥其抑制效应。     

细胞因子对树突状细胞抗肝癌作用的影响

目的研究人血树突状细胞（ＤＣ）和细胞因子ＴＮＦ,ＧＭＣＳＦ或ＩＦＮγ联合ＤＣ对淋巴因子和ＰＨＡ激活的杀伤细胞（ＬＰＡＫ细胞）体外杀伤人肝癌细胞株ＢＥＬ７４０２的影响．方法实验分为Ｌ组（ＬＰＡＫ）,Ｄ组（ＬＰＡＫ＋ＤＣ）,Ｔ１组（ＬＰＡＫ＋ＤＣ＋ＴＮＦ５０００ｋＵ／Ｌ）,Ｔ２组（ＬＰＡＫ＋ＤＣ＋ＴＮＦ５００ｋＵ／Ｌ）,Ｇ１组（ＬＰＡＫ＋ＤＣ＋ＧＭ－ＣＳＦ５００ｋＵ／Ｌ）,Ｇ２组（ＬＰＡＫ＋ＤＣ＋ＧＭ－ＣＳＦ１００ｋＵ／Ｌ）,Ｉ１组（ＬＰＡＫ＋ＤＣ＋ＩＦＮγ５００ｋＵ／Ｌ）和Ｉ２组（ＬＰＡＫ＋ＤＣ＋ＩＦＮγ１００ｋＵ／Ｌ）．每组效靶细胞比分别采用５∶１和１０∶１两种．培养４８ｈ后用中性红比色法检测细胞毒活性．结果Ｌ,Ｄ,Ｔ２和Ｔ１组的细胞毒活性依次增强,各组间差异有显著性（Ｐ＜００１）．Ｇ１和Ｇ２组均高于Ｄ组（Ｐ＜００１）,但Ｇ１,Ｇ２组间差异无显著性．Ｉ１,Ｉ２组与Ｄ组相比,也无显著性差异．随效靶比增加,各组细胞毒活性均相应增强．结论ＤＣ能增强ＬＰＡＫ细胞对肝癌细胞ＢＥＬ７４０２的细胞毒活性;ＴＮＦ或ＧＭＣＳＦ与ＤＣ联用,两者有协同作用;但与ＩＦＮγ联用,则无进一步增强作用     

含弓形虫ROP1基因真核表达重组质粒DNA免疫小鼠的研究Ⅴ.IFN-γ基因真核表达重组质粒的构建及其在DNA免疫中基因佐剂的作用

目的　构建ＩＦＮ－γ基因真核表达重组质粒作为基因佐剂,观察其与ｐｃＤＮＡ３－ＲＯＰ１（ｐｃ－ＲＯＰ１） ＤＮＡ共同免疫小鼠所诱导的免疫应答。方法　将ＩＦＮ－γ基因片段定向插入真核表达载体ｐｃＤＮＡ３,双酶切鉴定,获得ｐｃＩＦＮ 重组子;碱裂解法大量制备,经肌肉注射免疫ＢＡＬＢ／ｃ小鼠,每只鼠注射ｐｃＩＦＮ、ｐｃ－ＲＯＰ１ 各１００μｇ,两周后同量加强免疫一次,以ｐｃＤＮＡ３空质粒及生理盐水组为对照。分别于免疫后第３０ 天、５０ 天、７０天共三次用ＭＴＴ法测定小鼠脾脏Ｔ淋巴细胞增殖活性及ＮＫ细胞活性;双夹心ＥＬＩＳＡ 测定血清细胞因子ＩＦＮ－γ、ＩＬ－２及酶法测定ＮＯ含量;ＥＬＩＳＡ法测定ＩｇＧ抗体滴度。结果　构建成功的作用下,该两项指标均明显提高,且ＩＦＮ－γ、ＩＬ－２ 及ＮＯ水平均较不加佐剂组显著提高（Ｐ＜ ０．０１）;而对ＩｇＧ抗体滴度无显著影响（Ｐ＞ ０．０５。结论　ＩＦＮ－γ基因佐剂具有协同ｐｃ－ＲＯＰ１ＤＮＡ免疫的作用,可增强免疫鼠细胞免疫应答,ＩＦＮ－γ、ＩＬ－２细胞因子及ＮＯ的产生     

慢性肾衰患者血清及尿液γ-干扰素的检测及其意义

采用ＥＬＩＳＡ双抗体夹心法检测７１例慢性肾衰（ＣＲＦ）患者及４０例健康成人血及尿的γ－干扰素（ＩＦＮ－γ）水平。结果显示：ＣＲＦ患者血清及尿液ＩＦＮ－γ含量分别为（６２６２±２．６８）ｎｇ／Ｌ和（４３．０１±２．５７）ｎｇ／Ｌ，显著低于正常对照组，［（１０５±７．１０）ｎｇ／Ｌ和（７５±６．１４）ｎｇ／Ｌ］（Ｐ＜０００１），但与尿素氮（ＢＵＮ）及血清肌酐（Ｓｃｒ）无显著相关性（血清及尿ＩＦＮ－γ与ＢＵＮ、Ｓｃｒ相关系数分别是ｒ＝０．２４２５、０３０５６、０１５３３和０１７５０，Ｐ＞００５）。结论：ＩＦＮ－γ作为一种细胞因子参与肾脏病发生、发展过程中的网络调节，血清及尿液中ＩＦＮ－γ水平受到机体Ｔ淋巴细胞及ＮＫ细胞数量及功能影响。     

固真方对老年大鼠下丘脑—垂体—甲状腺轴和免疫功能的影响

研究发现，与青年组比较，老年大鼠血清游离甲状腺素Ｔ４（ＦＴ４）、游离甲状腺素Ｔ３（ＦＴ３）水平明显下降，而血清３，３′，５′三碘甲腺原氨酸（ｒＴ３）水平显著升高，血清促甲状腺释放激素（ＴＲＨ）、促甲状腺激素（ＴＳＨ）呈代偿性增高，下丘脑ＴＲＨ明显下降，血清胸腺因子活性和脾细胞白介素２（ＩＬ２）活性降低。固真方可明显提高老年大鼠下丘脑ＴＲＨ、垂体ＴＳＨ，血清ＦＴ４与ＦＴ３，降低老年血清增高的ＴＲＨ、ＴＳＨ、ｒＴ３，使老年大鼠血清胸腺因子和ＩＬ２活性增高。     

韦格纳肉芽肿病T细胞表达及分泌细胞因子的研究—Th1型免疫反应

目的：通过分析Ｔ细胞细胞因子的表达和分泌，探讨韦格纳肉芽肿病（ＷＧ）的免疫反应类型。方法：用有限稀释法从ＷＧ患者鼻粘膜活检标本（ＮＢＳ）、支气管肺泡灌洗液（ＢＡＬ）及外周血中克隆出Ｔ细胞。用ＲＴＰＣＲ及ＥＬＩＳＡ检测其细胞因子的表达和分泌。结果：所有７株从ＮＢＳ克隆的Ｔ细胞只表达和分泌Ｔｈ１型细胞因子（ＩＦＮγ）。从ＢＡＬ克隆的３株Ｔ细胞，２株为Ｔｈ１型，另１株为Ｔｈ０型（表达和分泌ＩＦＮγ及ＩＬ４）。而从外周血中克隆的２７株Ｔ细胞。Ｔｈ１型（９株）多于Ｔｈ２型（２株），但多数（１６株）为Ｔｈ０型。另外，ＷＧ患者外周血中未分类的多克隆ＣＤ＋４和ＣＤ＋８Ｔ细胞产生ＩＦＮγ的量明显高于正常对照者，而ＩＬ４表达和分泌则与正常无差别。结论：ＷＧ的免疫病理过程主要表现为Ｔｈ１型免疫反应     

细胞因子对正常甲状腺细胞cAMP生成的调节

目的　本文研究白介素１（ Ｉ Ｌ１） 、干扰素α（ Ｉ Ｆ Ｎα） 和肿瘤坏死因子（ Ｔ Ｎ Ｆ） 对人正常甲状腺细胞环磷酸腺苷（ｃ Ａ Ｍ Ｐ） 生成的影响。方法　运用人甲状腺细胞原代培养技术和放免分析技术，检测不同种类细胞因子刺激甲状腺细胞引起的ｃ Ａ Ｍ Ｐ 释放状况。结果　（１） Ｉ Ｌ１ 、 Ｉ Ｆ Ｎα和 Ｔ Ｎ Ｆ 均可促进甲状腺细胞基础ｃ Ａ Ｍ Ｐ 的释放。（２） Ｉ Ｌ１ 在１０ － ３ ～１０３ Ｕ／ｍｌ 的浓度范围内，可明显增强促甲状腺激素（ Ｔ Ｓ Ｈ） 对甲状腺细胞生成ｃ Ａ Ｍ Ｐ 的刺激效应，其中以１０ － １ Ｕ／ｍｌ 的 Ｉ Ｌ１ 作用最强。（３） Ｉ Ｆ Ｎα对 Ｔ Ｓ Ｈ 刺激甲状腺细胞ｃ Ａ Ｍ Ｐ 的生成具有双向调节作用，１０ － ２ ～１ Ｕ／ ｍｌ 可增加ｃ Ａ Ｍ Ｐ 释放，而１０３ Ｕ／ｍｌ 时则抑制 Ｔ Ｓ Ｈ 的刺激效应。（４）１０ ～１０４ Ｕ／ｍｌ 的 Ｔ Ｎ Ｆ 使 Ｔ Ｓ Ｈ 刺激甲状腺细胞生成ｃ Ａ Ｍ Ｐ 的量显著减少。结论　多种细胞因子参与甲状腺功能的调节，并可能与自身免疫性甲状腺疾病的发生发展过程有一定关联。     

类风湿关节炎中转化生长因子β1和细胞间粘附分子的变化

目的：了解类风湿关节炎（ＲＡ）血清、滑液和滑膜组织中转化生长因β１（ＴＧＦβ１）、细胞间粘附分子１（ＩＣＡＭ１）及细胞间粘附分子３（ＩＣＡＭ３）的变化。方法：采用ＥＬＩＳＡ及ＡＢＣ免疫组化方法检测ＲＡ患者血清、滑液和滑膜中ＴＧＦβ１、ＩＣＡＭ１和ＩＣＡＭ３的浓度和阳性程度。结果：ＲＡ血清中ＴＧＦβ１含量较低，而ＩＣＡＭ１含量明显升高，ＩＣＡＭ３含量正常，滑液中ＩＣＡＭ３含量低于血清含量。ＲＡ血清中ＴＧＦβ１含量与ＩＣＡＭ１含量呈中度负相关，与ＩＣＡＭ３含量无显著相关。在ＲＡ滑膜中巨噬细胞、滑膜衬里细胞和成纤维细胞ＴＧＦβ１染色阳性，巨噬细胞、滑膜衬里细胞、成纤维细胞和血管内皮细胞ＩＣＡＭ１染色阳性。结论：ＴＧＦβ１和ＩＣＡＭ１参与了ＲＡ的发生和发展过程，在ＲＡ慢性炎症中，ＩＣＡＭ１对炎细胞转移并聚集于滑膜可能有重要作用，ＲＡ外周血ＴＧＦβ１浓度减低伴随ＩＣＡＭ１浓度的增加。     

Age-related reduction in estrogen receptor-mediated mechanisms of vascular relaxation in female spontaneously hypertensive rats

Hypertension increases with aging, and changes in vascular estrogen receptors (ERs) may play a role in age-related hypertension in women. We tested whether age-related increases in blood pressure in female spontaneously hypertensive rats (SHRs) are associated with reduction in amount and/or vascular relaxation effects of estrogen and ER. Arterial pressure and plasma estradiol were measured in adult (12 weeks) and aging (16 months) female SHRs, and thoracic aorta was isolated for measurement of active stress, 45Ca2+ influx, and ERs. Arterial pressure was greater and plasma estradiol was less in aging females than in adult females. In aorta of adult females, Western blots revealed alpha- and beta-ERs that were slightly reduced in aging rats. In endothelium-intact vascular strips, phenylephrine (Phe; 10(-5) mol/L) caused greater active stress in aging rats (9.3+/-0.2) than in adult rats (6.2+/-0.3x10(4) N/m2). 17beta-estradiol (E2) caused relaxation of Phe contraction and stimulation of vascular nitrite/nitrate production, which was reduced in aging rats. In endothelium-denuded strips, E2 still caused relaxation of Phe contraction, which was smaller in aging rats than adult rats. KCl (51 mmol/L), which stimulates Ca2+ influx, produced greater active stress in aging rats (9.1+/-0.3) than in adult rats (5.9+/-0.2x10(4) N/m2). E2 caused relaxation of KCl contraction and inhibition of Phe- and KCl-induced 45Ca2+ influx, which were reduced in aging rats. Thus, aging in female SHR is associated with reduction in ER-mediated NO production from endothelial cells and decrease in inhibitory effects of estrogen on Ca2+ entry mechanisms of smooth muscle contraction. The age-related decrease in ER-mediated vascular relaxation may explain the increased vascular contraction and arterial pressure associated with aging in females.     

The Expression of Estrogen Receptor is Dependent on the Estrogen Level and Associated with Cholesterol - Rich Diet in Female Rat''''s Heart and Vascular Endothelial Cells

Objective To study the effects of estrogen level and cholesterol - rich diet on the expression of estrogen receptor (ER) in cardiovascular tissues including vascular endothelial cells (VEC) of female rats. Methods The receptor binding assay (RBA) was adopted to measure the estrogen receptor level in aortic wall, heart and vascular endothelial cells of female rats on a cholesterol - rich diet. A ra-dioimmunoassay was employed to measure the level of serum estradiol. Results The number of ER significantly decreased in hearts, aorta and vascular endothelial cells in the ovariectomized rats and the rats on a cholesterol - rich diet. In contrast, the administration of estrogen somewhat restored the expression of ER. Conclusions For female rats, the level of estrogen affects the expression of ER in cardiovascular system. The number of ER decreases along with the decrease in the level of estrogen. A cholesterol - rich diet also can decrease the expression of ER in cardiovascular system of female rats.     

Aging and substitutive hormonal therapy influence in regional and subcellular distribution of ERα in female rat brain

Estrogens are not only critical for sexual differentiation it is well-known for the role of 17β-estradiol (E2) in the adult brain modulating memory, learning, mood and acts as a neuroprotector. E2 exerts its actions through two classical receptors: estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ). The distribution of both receptors changes from one brain area to another, E2 being able to modulate their expression. Among the classical features of aging in humans, we find cognitive impairment, dementia, memory loss, etc. As estrogen levels change with age, especially in females, it is important to know the effects of low E2 levels on ERα distribution; results from previous studies are controversial regarding this issue. In the present work, we have studied the effects of long-term E2 depletion as well as the ones of E2 treatment on ERα brain distribution of ovariectomized rats along aging in the diencephalon and in the telencephalon. We have found that ovariectomy causes downregulation and affects subcellular localization of ERα expression during aging, meanwhile prolonged estrogen treatment produces upregulation and overexpression of the receptor levels. Our results support the idea of the region-specific neuroprotection mechanisms mediated by estradiol.     

Dehydroepiandrosterone restoration of growth hormone gene expression in aging female rats, in vivo and in vitro: evidence for actions via estrogen receptors

A decline in dehydroepiandrosterone (DHEA) and GH levels with aging may be associated with frailty and morbidity. Little is known about the direct effects of DHEA on somatotropes. We recently reported that 17beta-estradiol (E2), a DHEA metabolite, stimulates the expression of GH in vitro in young female rats. To test the hypothesis that DHEA restores function in aging somatotropes, dispersed anterior pituitary (AP) cells from middle-aged (12-14 months) or young (3-4 months) female rats were cultured in vitro with or without DHEA or E2 and fixed for immunolabeling or in situ hybridization. E2 increased the percentage of AP cells with GH protein or mRNA in the aged rats to young levels. DHEA increased the percentages of somatotropes (detected by GH protein or mRNA) from 14-16 +/- 2% to 29-31 +/- 3% (P < or = 0.05) and of GH mRNA (detected by quantitative RT-PCR) only in aging rats. To test DHEA's in vivo effects, 18-month-old female rats were injected with DHEA or vehicle for 2.5 d, followed by a bolus of GHRH 1 h before death. DHEA treatment increased serum GH 1.8-fold (7 +/- 0.5 to 12 +/- 1.3 ng/ml; P = 0.02, by RIA) along with a similar increase (P = 0.02) in GH immunolabel. GHRH target cells also increased from 11 +/- 1% to 19 +/- 2% (P = 0.03). Neither GH nor GHRH receptor mRNAs levels were changed. To test the mechanisms behind DHEA's actions, AP cells from aging rats were treated with DHEA with or without inhibitors of DHEA metabolism. Trilostane, aminogluthemide, or ICI 182,780 completely blocked the stimulatory effects of DHEA, suggesting that DHEA metabolites may stimulate aging somatotropes via estrogen receptors.     

Age-related changes in estrogen receptor beta in rat hypothalamus: a quantitative analysis

Although the estrogen receptor beta (ER beta) is a major target for actions of estrogen on the brain, little is known about its neural expression during aging, when levels and the mode of estrogen release undergo substantial changes. Therefore, in the present study we examined effects of aging and estrogen treatment on the number of cells expressing the ER beta in female rats. Two regions relevant to reproductive function were analyzed: the anteroventral periventricular nucleus (AVPV) and the principal nucleus of the bed nucleus of the stria terminalis (pBST). The numbers of ER beta-expressing cells were quantified using an unbiased stereological approach. Female rats were used at three ages [young (3-4 months), middle-aged (10-12 months), and old (24-26 months)], with or without estrogen replacement. Because the estrogen milieu impacts the function of neurotransmitter receptors such as the N-methyl-D-aspartate receptor in the brain, we also investigated the colocalization of ER beta and the obligatory N-methyl-D-aspartate receptor subunit, NR1. We observed a significant age-related decrease in ER beta cell number in the AVPV, but not the pBST. No significant effect of estrogen on ER beta cell number was detected in either brain region at any age. Approximately 10% and 3% of cells expressing ER beta also coexpressed NR1 in AVPV and pBST, respectively, and this did not differ with age or treatment. Taken together, our results demonstrate 1) there are age-related changes in ER beta cell number that are region specific; 2) this expression is not altered by estrogen replacement; and 3) a subset of ER beta-positive cells coexpresses NR1.     

Effects of age on hormone levels and in vitro steroidogenesis by rat ovary and adrenal

In order to evaluate age-related changes in ovarian and adrenal steroid production, in vitro steroid production by adrenal glands and ovaries from young (3-4 mo) and middle-aged (10-11 mo) cycling rats was compared to serum steroid and gonadotropin levels on each morning of the estrous cycle. Basal LH levels were not different between young and mid-aged cycling rats except on estrus, when elevated estrogen (E) levels were correlated with depressed LH in the mid-aged rats. Basal FSH levels were generally elevated in mid-aged cycling and mid-aged constant estrus (CE) rats, but the FSH rise on estrus morning was not seen in the mid-aged rats. Serum progesterone levels were not changed with age or reproductive state, although in vitro ovarian progesterone secretion was decreased in mid-aged CE rats. Adrenal progesterone secretion increased significantly with age. Serum total testosterone was similar in young and mid-aged cycling and mid-aged CE rats, despite a highly significant increase in in vitro testosterone secretion by the CE ovary. Serum estradiol (E2) levels were significantly elevated on proestrus and estrus in the mid-aged rats. Although estrone (E1) levels appeared higher in the mid-aged than in the young cycling rats, the differences were not significant. Mid-aged CE rats had significantly elevated serum levels of both E1 and E2. In vitro ovarian estrone production was depressed in mid-aged cycling rats. Adrenal total estrogen production was similar in young and mid-aged animals. These results demonstrate that serum gonadotropin and steroid levels are altered in aging female rats prior to the loss of reproductive cycles. Changes in serum steroid levels are probably due to changes in circulating LH and FSH levels or the ovarian response to these gonadotropins, but changes in vitro basal steroid production suggest that intrinsic ovarian function may also change with advancing age. As rats enter a CE state, alterations in basal ovarian and adrenal steroid production are seen and may be partially responsible for maintenance of the acyclic state.     

Sexually dimorphic and estrogen-dependent expression of estrogen receptor beta in the ventromedial hypothalamus during rat postnatal development

The ventromedial hypothalamus (VMH) is a sexually dimorphic region of the brain related to female reproductive behavior. The effect of estrogen in the adult rat VMH is thought to be mediated predominantly via estrogen receptor (ER)alpha, because this receptor is expressed at considerably higher levels than ER beta. The present study revealed, using in situ hybridization and immunohistochemistry, that both ER beta mRNA and protein were expressed in the ventrolateral portion of the caudal VMH, at remarkably higher levels during early postnatal development than in adulthood. In addition, the expression was sexually dimorphic, with females having significantly more ER beta-immunoreactive (-ir) cells than males, between postnatal d 5 (P5) and P14, although the sex difference was not significant by P21. Double-label immunofluorescence revealed that 66% of ER beta-ir cells coexpressed ER alpha in the caudal VMH of the P5 female rat. Furthermore, neonatal treatment with E2 benzoate down-regulated ER beta mRNA in the female rat VMH at P5 and decreased VMH ER beta-ir cells during the period between P5 and P14. In contrast to females, no differences in expression of ER beta mRNA or protein were detected between control and E2 benzoate-treated males. These results suggest that estrogen is involved in regulating the sexually dimorphic expression of ER beta in the VMH during early postnatal development of the rat.     

Effect of Estradiol and Progesterone Treatment on Carbohydrate Metabolizing Enzymes in Tissues of Aging Female Rats

The aim of this study was to determine the effect of administration of estradiol (E2), progesterone (P4), and combination of estradiol and progesterone (EP) in aging female rats. The changes in the activities of hexokinase (HK), glucose-6-phosphatase (G6P'tase) and glucose-6-phosphate dehydrogenase (G6PDH) enzymes, and in protein levels in tissues of rats namely brain (cerebral hemisphere), heart, liver, kidney and uterus have been measured in different age groups. The random blood sugar level was measured in serum and liver. The different age groups of rats were given 0.1 microg/g body weight estradiol, 2.5 microg/g body weight progesterone and a similar concentration of both in a combined treatment for 1 month. This dose was selected after determining estrogen and progesterone levels in 3 month adult female animals so that the aging female animals had circulating hormone levels nearly the same as those of young female animals. The random sugar level was determined in serum and liver cytosolic fractions, and it was increased by combination treatment. The protein content in tissues showed significant changes only with combined hormone administration when compared with age-matched controls. The activity of HK decreased in aged animals and significantly increased by hormone treatments in all the tissues of the aged rats studied. The activity of G6P'tase increased with age up to 1.5 years and decreased in 2 years. Treatment with E2 and EP further decreased the activity significantly in all the tissues. G6PDH showed a similar pattern as was observed in HK in all the age groups. Therefore, the E2 and EP treatments caused an entire series of growth-related responses, including an increased uptake of glucose, increased the protein level in the tissues of aging rats, thereby reducing the risk factors associated with aging by normalizing hormone levels which decreased with aging and resulted in diseases such as Alzheimer's diseases and diabetes.     

Evidence for genomic and nongenomic actions of estrogen in growth plate regulation in female and male rats at the onset of sexual maturation

Recently, both estrogen receptor (ER) alpha and beta were detected in growth plate chondrocytes of rats before sexual maturation, implying a role for estrogen at this stage. In this study, therefore, we investigated the effects of ovariectomy (OVX) or estrogen supplementation on parameters of longitudinal growth in 26-day-old rats, which were sexually immature at the start of the experiment. OVX caused an increase in body weight gain, tibial length and growth plate width due to an increased proliferating zone. This increase correlated with an increase in cell number, with a decrease in cell diameter and with increased proliferating cell nuclear antigen (PCNA) immunostaining compared with sham. Interestingly, the increase in proliferation was not caused by an increase in insulin-like growth factor-I (IGF-I) mRNA expression in the growth plate as assessed by real-time PCR. In contrast to OVX, 17beta-estradiol (E(2)) supplementation (0.5 mg/21 days) of 26-day-old female rats caused a strong decrease in body weight gain, tibial length and growth plate width. The latter was explained by a reduction of the proliferating zone width, which correlated with a reduced number of PCNA-positive cells (not significant) and by a reduction of the hypertrophic zone width. In male rats supplemented with E(2), similar effects were observed compared with the females. ERalpha and beta immunostaining was found predominantly in late proliferating and early hypertrophic chondrocytes. OVX did not affect ER expression but E(2) supplementation strongly decreased immunostaining for both ERalpha and beta in both sexes. Besides E(2), desoxyestrone (DE), an activator of nongenomic estrogen-like signaling (ANGEL) and 2-methoxyestradiol (2-MeO-E(2)), a tissue-selective naturally occurring metabolite of E(2), were administered to female and male rats of the same age. Compared with E(2), these compounds had less pronounced, though significant, effects on some parameters of longitudinal growth in both sexes, especially on growth plate characteristics. In conclusion, E(2) may exert effects on longitudinal growth before and at the onset of sexual maturation, despite very low endogenous serum levels at these stages. There may be a role for nongenomic signaling in body weight gain, tibial length and growth plate width but genomic signaling prevails.