FOLLICULO-STELLATE CELLS OF THE RAT ANTERIOR PITUITARY RESPONDED TO ANGIOTENSIN Ⅱ BY INCREASING INTRACELLULAR Ca^(2+) CONCENTRATION

Objective The main purpose of this study was to investigate whether the folliculo stellate cells (FSC) respond to angiotensin(Ang)Ⅱ by increasing intracellular free Ca 2+ concentration ([Ca 2+ ]i),and where the origin of Ca 2+ mobilization is if that has occurred.Methods Pituitary cells in primary culture were prepared from male Wister rats(250g) by a conventional method and cultured in MEM supplemented with 4% normal rat serum.After 2 days in culutre,cells were loaded with 1 μmol/L fura PE3/AM for 1 h and subjected to a Ca 2+ imaging experiment with Quanti Cell 700 system.Excitation wavelengths of 340 and 380 nm were selected by means of a computer controlled filterwheel.Results The [Ca 2+ ]i of FSC in the rat anterior pituitary was elevated by Ang Ⅱ.The elevation of [Ca 2+ ]i of FSC induced by 0.1,1.0,10 and 100 nmol/L Ang Ⅱ was (56.33±6.18)( ±s ),(117.07±36.07),(175.59±40.01) and (216.02±11.52) nmol/L,respectively.The increase of [Ca 2+ ]i of FSC induced by 100 nmol/L Ang Ⅱ was not influenced by the medium without Ca 2+ (0Ca),but significantly suppressed by thapsigargin(TG),an inhibitor of ATPase.The rate of responsive FSC to Ang Ⅱ (100 nmol/L) was 61.84% which was obviously higher than that of pituitary endocrine cells(43.49%).Conclusion The present experiment demonstrates that the FSC in the rat anterior pituitary responds to Ang Ⅱ by increasing [Ca 2+ ]i,which raises the possibility that Ang Ⅱ released from either lactotrophs or gonadotrophs affects FSC through paracrine mechanism.The elevation of [Ca 2+ ]i induced by Ang Ⅱ presents a dosage dependent relation, and is possibly because of the release of Ca 2+ from an intracellular Ca 2+ pool(s).Fashions of Ca 2+ release are relative to the concentration of Ang Ⅱ.The results indicate that Ang Ⅱ functions as a paracrine factor among pituitary cells including FSC.

大鼠垂体前叶腺细胞增龄变化及其与滤泡星形细胞的关系

目的:研究不同月龄大鼠垂体前叶腺细胞的形态学变化及其与滤泡星形细胞(folliculo-stellate cells,FSCs)之间的形态学关系。方法:透射电镜观察2～3月(青年组)、10～12月(中年组)、18～20月(老年组)3组大鼠垂体前叶的超微结构。结果:3组大鼠的FSCs和腺细胞之间均存在连接复合体样结构;在增龄过程中,FSCs的形态变化不明显,而腺细胞及其细胞间质变化明显:细胞排列散乱、细胞间隙增宽、纤维结缔组织增生,以中年组较为显著;脂褐素、髓样体、凋亡细胞增多,老年组比较明显。结论:FSCs可能通过与腺细胞的直接接触对腺细胞发挥作用;垂体前叶腺细胞及其细胞间隙的变化直接反映其增龄变化。

不同月龄大鼠垂体前叶滤泡星形细胞S100蛋白的表达

目的:观察不同月龄大鼠垂体重量、垂体前叶3类细胞比例及滤泡星形细胞(FS细胞) S100蛋白表达的形态学变化.方法:选取2～3月(青年组)、10～12月(中年组)、18～20月(老年组)3 组大鼠垂体经分析天平称重后,行HE染色和免疫组化ABC法观察垂体前叶S100蛋白的表达.结果:中年组垂体重量最大;垂体前叶嫌色细胞(其中多为滤泡星形细胞)所占比例以中年组最高(39.26%±0.10%);3年龄组S100蛋白阳性细胞的分布方式不同;细胞阳性率以中年组最高(27.13%±0.16%),与其它两组比较有显著差异.结论:中年组大鼠垂体重量、垂体前叶FS细胞的数量、分布与其它两组比较变化最大.在大鼠垂体前叶增龄过程中,FS细胞发挥着重要作用.

间隙连接蛋白Cx43在去卵巢雌鼠腺垂体滤泡星形细胞中的表达

目的 探讨间隙连接蛋白 Cx4 3在骨质疏松 (OP)雌鼠腺垂体滤泡星形细胞 (FS细胞 )中的表达规律及其生物学意义。方法 采用 10月龄未孕产 SD雌性大鼠 4 0只 ,随机分为去卵巢组和对照组 ,于术后 6周处死两组大鼠。处死前测量大鼠全身骨密度。取大鼠垂体 ,应用 SP免疫组化方法检测大鼠腺垂体 FS细胞中间隙连接蛋白 Cx4 3的表达。结果 术后 6周末去卵巢组大鼠全身骨密度明显低于对照组大鼠骨密度 (P<0 .0 1)。腺垂体中 Cx4 3阳性表达主要定位于相邻的 FS— FS、FS—内分泌细胞中 ,上述细胞的胞浆和 /或胞膜呈棕黄色。去卵巢组大鼠腺垂体 Cx4 3的表达阳性率和阳性信号的表达强度均明显降低 (P<0 .0 1)。结论 SD雌性大鼠去卵巢 6周建立 OP模型。OP模型腺垂体中 Cx4 3蛋白在上述细胞中表达下降可能是大鼠 OP发生的一个环节。

58例垂体腺瘤的病理生物学研究

本文应用S100蛋白和6种垂体激素抗血清,通过免疫组织化学方法研究了58例垂体腺瘤的生物学类型。结果表明:功能性垂体腺瘤34. 5％,无功能性垂体腺瘤65. 5％。功能性垂体腺瘤以GH阳性者居多,同时产生两种激素的腺瘤也较常见,其组合方式两例为GH^+PRL,一例为GH+TSH。无功能性垂体腺瘤有两种类型,一类S100和6种激素均阴性,另一类为S100蛋白阳性,前者我们称为无特殊标记之无功能垂体腺瘤,后者称为滤泡星状细胞腺瘤。本文还讨论了滤泡星状细胞,在垂体腺瘤中的存在及意义。

垂体前叶滤泡星状细胞来源的免疫组织化学研究

应用纤维连接素(Fn)、S—100蛋白、胶质纤维酸性蛋白(GFAP)、细胞角蛋白(CK)和神经特异性烯醇蛋白(NSE)5种抗体对63例正常人垂体前叶内滤泡星状细胞(FSC)进行了免疫细胞化学研究。结果表明:人FSC内26.9％S_(100)阳性,9.3％GFAP阳性,63.8％两者都为阳性。CK、NSE和Fn均为阳性。从而提示了FSC来自神经外胚层的原始细胞而非Rathke's囊上皮的残留。