P物质对培养的大鼠垂体前叶细胞IP3含量的影响

目的:探讨SP对大鼠AP培养细胞IP3水平的影响,进一步阐述SP的生物学效应机制.方法:应用液闪测定AP细胞内IP的计数率(count/min).结果:在一定时间范围内SP以时间依赖的方式增加SD大鼠AP细胞内IP3的含量.结论:兴奋AP细胞,在一定时间内生物学效应有一部分是通过IP3来完成的,在信息转导途径上为SP对生殖轴调控理论作进一步证明和补充.     

P物质在再生视网膜节细胞中的表达及IBMX和CPT-cAMP 对其表达的影响

采用金黄地鼠视神经切断并缝接坐骨神经的再生实验模型,玻璃体内注射IBMX或/和CPT-cAMP,荧光金逆行标记再生的RGCs结合P物质免疫荧光组化双标法,研究外周神经缝接于视神经断端能否促进P物质阳性的视网膜节细胞(RGCs)再生及IBMX或/和CPT-cAMP处理对其再生的影响。实验结果:①术后四周,对照AG组每个视网膜 再生RGCs数1329±104,双标细胞平均数为45±5,占再生RGCs总数的3.4％;②AG+IBMX组每个视网膜再生RGCs数为2099±419,再生P物质阳性节细胞平均数为119±22,占再生RGCs总数的6.55％;③AG+cAMP组每个视网膜再生RGCs数为2048±133,再生P物质阳性节细胞平均数为127±37,占再生RGCs总数的6.15％;④AG+IB-MX+cAMP组每个视网膜再生RGCs数为4370±487,再生P物质阳性节细胞平均数为339±72,占再生RGCs总数的7.98％,与对照组的差异具有统计学意义。表明成年哺乳动物P物质阳性RGCs能再生,玻璃体内注射IBMX或/和CPT-cAMP可以促进该类RGCs再生。     

小鼠脊髓背根神经节细胞共培养中P物质神经元的形态学观察

小鼠脊髓－背根神经节细胞在体外共培养状态Ｐ物质神经元的形态在国内尚未见文献报道。我们利用体外培养及免疫细胞化学方法对Ｐ物质神经元的胞体及突起形态做了观察,发现背根神经节中Ｐ物质免疫反应阳性的胞体为圆形成近似圆形,胞体直径大约为２８μｍ,突起较长,可有多级分枝。脊髓细胞中Ｐ物质反应阳性胞体多为圆形或椭圆形,胞体直径大约为１３μｍ左右,其突起有单极、双极和多极。在这种共培养状态下,Ｐ物质阳性反应纤维均比较纤细,但有的少见膨体,有的则膨体多见     

P物质对大鼠分离的DRG细胞GABA激活电流的抑制作用

本文就用全细胞膜片箝技术,在新鲜分离的大鼠ＤＲＧ细胞上证明,在部分细胞Ｐ物质（１０＾－７－１０＾－５ｍｏｌ／Ｌ）可引起浓度依赖性的内向流（４／２６）;在多数细胞虽未检测到ＳＰ引起的膜电流,但却能对ＧＡＢＡＡ受体激活介导的膜内向流产生抑制效应（１８／２２）,并有加速去敏感的作用。本文就有关ＳＰ以ＧＡＢＡ激活电流抑制效应的可能意义进行了讨论。     

P物质对大鼠DRG神经元胞体膜的作用

本文在大鼠ＤＲＧ神经元标本上应用细胞内记录,以确定ＳＰ对ＤＲＧ细胞的膜反应及其可能的离子机制。实验所测ＤＲＧ细胞静息膜电位为－５８．９±８．２ｍＶ（Ｘ±ＳＥ,ｎ＝８１）。传导速度：Ａ_（α／β）细胞为２０．４±４．８ｍ／ｓ（Ｘ±ＳＥ）,范围１４．１－２８．７ｍ／ｓ（４７／６０）;Ａδ及Ｃ类细胞为９．８±５．２ｍ／ｓ,范围１．２－１３．７ｍ／ｓ（１３／６０）。浴槽滴加ＳＰ（１０￣（－７）－３×１０￣（－４）ｍｏｌ／Ｌ）在大多数细胞可引起明显的膜去极化反应（５６／６０）。少数细胞对ＳＰ无反应（４／６０）。在ＳＰ去极化期间膜电导值有所增加,从平均值２．７２×１０￣（－８）ｍｈｏ增加２４．６％（ｎ＝３）。所测逆转电位值在＋４０－＋５０ｍＶ之间（ｎ＝３）。浊流平衡液（ＢＳＳ）中ＮａＣｌ以氯化胆碱置代,或用含ＴＴＸ（１０￣（－５）ｍｏｌ／Ｌ）的ＢＳＳ灌流,可使ＳＰ－去极化幅值大大减小但不能完全消除。而高（２０ｍｍｏｌ／Ｌ）和低（０ｍｍｏｌ／Ｌ）Ｃａ￣（２＋）的ＢＳＳ灌流时,使ＳＰ－去极化幅值相应的增加和降低。用含１０￣（－４）ｍｏｌ／ＬＣｄ￣（２＋）及１０￣（－２）ｍｏｌ／ＬＴＥＡ的ＢＳＳ灌流,均使ＳＰ－去极化明显减小。     

P物质对动情期大鼠下丘脑—垂体轴系的调控

自Vijayan首次报道P物质(SP)与生殖功能有关以来,SP对生殖活动的影响已开始引起人们的注意。我们的研究工作初步证明在雌性大鼠不同性周期中,下丘脑SP含量最高,垂体次之,卵巢内含量最低,并以间情期含量为最高,情前期次之,动情期最低;而血清中孕酮含量与SP含量呈反比关系。侧脑室注入SP拈抗剂可对抗SP对卵巢孕酮生成的抑     

P物质对蟾蜍离体心脏活动的影响

P物质(substance P,SP)既是一个局部作用激素、又是一个循环激素,在体内可对许多器官发挥作用,对心血管活动的调节具有重要影响,在这方面以对血管活动的影响研究较多,对心脏活动的影响报道较少,对其作用机制尚不十分清楚。本工作试图在蟾蜍离体心脏标本上观察SP对心脏活动的直接效应,并初步探讨其作用机制。     

Orexin 和P物质对顺铂诱发大鼠异食癖的影响

目的:观察食欲素(Orexin)和P物质(SP)对顺铂诱发大鼠异食癖的影响。方法:雄性Wistar大鼠被随机分为对照组和顺铂处理组,顺铂处理组给予大鼠顺铂(3或6 mg/kg,腹腔注射),对照组给予等量生理盐水。记录顺铂大鼠摄食高岭土量、摄食量的改变;Real-time PCR法观察顺铂对大鼠下丘脑Orexin和延髓中SP前体-前速激肽原A(PPT-A)m RNA表达的影响;分别和联合应用SP受体(NK1受体)拮抗剂阿瑞匹坦和Orexin-A对顺铂大鼠异食癖和摄食量的作用。结果:皮下注射3 mg/kg(低剂量组)的顺帕后大鼠高岭土摄入量和摄食量与对照组相比无明显差异(P0.05),而注射6 mg/kg(高剂量组)顺铂后,大鼠高岭土摄入量与对照组和低剂量组相比显著增加(P0.05);高剂量的顺铂作用12 h时,大鼠延髓内PPT-A的m RNA表达有轻微增加,但无统计学差异(P0.05),24 h后,延髓内PPT-A的m RNA表达量显著增加(P0.05)。在此后持续观察的5天中,顺铂可持续引起延髓中PPT-A的mRNA表达增高,在第5天时PPT-A的m RNA仍维持166.23±16.92%的高表达。高剂量顺铂抑制大鼠下丘脑中Orexin的mRNA表达,24 h时Orexin降低幅度最明显,为对照组的34.81±7.22%(P0.05)。此后检测的5天,Orexin浓度均低于对照组;将阿瑞匹坦和orexin联合应用,大鼠高岭土摄入量较单独应用阿瑞匹坦或orexin明显减少,摄食量显著增加(P0.05)。结论:P物质和orexin通路对顺铂化疗大鼠的异食癖和摄食量调控具有协同作用。     

黑质内微量注射P物质对大鼠旋转行为的影响

研究表明 ,帕金森病 (ＰＤ)的发生是因中脑黑质多巴胺 (ＤＡ)能神经元变性 ,导致纹状体内ＤＡ释放量减少所致。目前有补充ＤＡ ,应用Ｍ受体阻断剂 ,脑内刺激及基因移植等治疗方法 ,但不能缓解所有症状。有人证明帕金森病时 ,黑质内Ｐ物质和ＧＡＢＡ的浓度明显低于正常 ,且降低幅度与发病的严重程度呈平行关系。说明帕金森病的发生可能还与黑质 纹体 黑质之间的其它神经递质作用失衡有关。黑质是Ｐ物质和ＧＡＢＡ含量很高的核团之一 ,对黑质的功能有重要的调节作用。本研究采用黑质网状部微量注射方法 ,观察不同浓度的Ｐ物质对ＡＰＯ诱发的…     

Partial characterization of immunoreactive substance P in the rat pituitary gland

Two distinct carboxy-terminus-directed anti-substance P (SP) sera (R-1C and R-6G) were used to characterize immunoreactive SP (I-SP) in acetic acid extracts of anterior pituitary (AP) and posterior pituitary (PP) glands of adult male rats. The tissue concentrations of I-SP measured by R-1C and R-6G were comparable. The contents of I-SP were 600–1150 pg/AP and 25–52 pg/PP. I-luteinizing hormone releasing hormone and I-somatostatin (I-SOM) were undetectable in AP extracts, but PP extracts contained the equivalents of 325–785 pg I-SOM/gland. Serial dilutions of AP and PP extracts produced displacement curves with both SP antisera that were parallel to the respective synthetic SP standard and hypothalamic extract displacement curves. Gel filtrations of AP and PP extracts on a Sephadex G-25 column produced I-SP peaks eluting in the same fractions as synthetic SP and hypothalamic I-SP. However, the AP I-SP profile also revealed a side peak migrating between the void volume and the major I-SP peak. Neither immunoreactive species in the AP extract were eliminated when eluted with 6.0 M guanidine HCl, a strong denaturing agent. $\text{In vitro}$ incubation of paired anterior hemipituitaries for 30 min in the presence of a 56 mM K⁺ concentration resulted in a significant (p<.0001), 25-fold increase in the release of I-SP into the incubation medium above the mean control value. Radiofrequency lesions placed in the median eminence-arcuate region of male rats caused a significant (p<.001) reduction of I-SP in both the AP and PP. These reductions were inversely related to the plasma prolactin values. The elevation in plasma prolactin was taken as an index of completeness of lesions. We conclude that: 1) the rat pituitary contains I-SP as assessed by its immunologic and chromatographic behavior, 2) K⁺ depolarization is a potent stimulator of the release of AP I-SP $\text{in vitro}$, 3) the ME-arcuate region is important for the maintenance of pituitary I-SP levels in the rat.     

Effect of substance P on thyrotropin secretion from the pituitary gland in the rat

The role of substance P (SP) on thyrotropin (TSH) secretion was investigated in ovariectomized (OVX) female, estrogen-primed OVX, and normal male rats. Third ventricular administration of SP induced a significant increase in plasma TSH levels when compared to control animals in E-primed OVX rats (p less than 0.001). The plasma TSH levels increased in a dose-related manner and reached maximum levels at 10 min after injection. In contrast, intraventricularly injected SP failed to alter plasma TSH levels in both OVX rats and normal male rats. Intravenous administration of SP dramatically stimulated TSH release in E-primed OVX rats (p less than 0.001), whereas SP had no effect on the release of TSH when injected in OVX rats and normal male rats. To investigate any direct action of SP on TSH release from the anterior pituitary gland, synthetic SP was incubated with dispersed anterior pituitary cells harvested from E-primed OVX rats and normal male rats. SP, in the dose range between 10(-8) M and 10(-6) M, failed to alter the release of TSH into the culture medium in vitro. These findings indicate that SP has a stimulatory role in the control of TSH release by an action on the hypothalamus but only in estrogen-primed rats.     

Microtubules in thyroidectomy cells of the rat anterior pituitary gland.

Microtubules were successfully illustrated in thyrotrophs and thyroidectomy cells of rat pituitary glands. In contrast, microfilaments were mostly seen in the nonglandular follicular cells. Numerous microtubules were observed in the early stages of development of the thyroidectomy cells. In thyroidectomy cells microtubules were located in close proximity to mitochondria, endoplasmic reticula, secretory granules, and membranes of Golgi complexes. Consequently, it is suggested that microtubules may play a role in degranulation or other processes associated with the hypersecretory state.     

Immunoreactive substance P content in median eminence and pituitary gland during oestrus, dioestrus and after anterior hypothalamic deafferentation

The aim of the present study was to find a relation between the Substance P (SP) content in the median eminence and the pituitary gland in rats and hypothalamic regulaton of the oestrus cycle. SP content was measured by radioimmunoassay in female rat pituitary and median eminence during oestrus, dioestrus and after anterior hypothalamic deafferentation. SP content in rat's pituitary did not vary significantly among individual groups of animals. The greatest average SP content in rat's median eminence was found in dioestrus. Both during cyclic and constant oestrus resulting from anterior hypothalamic deafferentation SP content in median eminence was lower than in dioestrus. This fact indicates the possibility of SP involvement in the control of cyclic LH-RH release from hypothalamus.     

Binding of an iodinated substance P analogue to cultured anterior pituitary prolactin- and luteinizing hormone-containing cells.

Several lines of anatomic, biochemical, and pharmacological evidence suggest that the neuropeptide substance P has a direct action on cells of the anterior pituitary lobe via a specific neurokinin-1 receptor. In the present study we confirmed this association by combining Bolton-Hunter iodinated substance P-receptor autoradiography with immunocytochemistry on cultured anterior pituitary cells. Radiolabeled substance P was bound to living cell cultures at 0 degrees C, and after a brief wash the cultures were fixed and processed immunocytochemically for prolactin and luteinizing hormone. A large proportion of cultured anterior pituitary cells possessed substance P binding sites. When receptor autoradiography was combined with immunocytochemistry, it was evident that both prolactin- and luteinizing hormone-immunoreactive cells were labeled with radiolabeled substance P. However, a small proportion of the radioligand-labeled cells were not stained by the immunocytochemical procedure, suggesting that additional cell types possess substance P receptors. The present study presents morphological evidence that substance P binds to prolactin- and luteinizing hormone-containing cells of the anterior pituitary lobe. Therefore, it is likely that substance P has a direct action on mammotrophs and gonadotrophs.     

Localization of microfilaments in prolactin cells of the rat anterior pituitary gland

Summary Prolactin cells from anterior pituitary glands of normal non-lactating female rats, and lactating animals, some of which were separated from their pups for 48 hours, were examined ultrastructurally for the presence of microfilaments. Microfilaments were found in specific intracellular locations in all cells examined. They were in association with the nuclear envelope, the Golgi complex, the endoplasmic reticulum, small vesicles of the endoplasmic reticulum, and secretory granules. The possible role of microfilaments in the movement of intracellular organelles is considered.This investigation was supported by the National Institutes of Health grants AM 12583 and TW 02023.The authors wish to express their gratitude to Mr. M. G. Williams and Miss Pauline Cisneros for their excellent technical assistance.     

Immunohistochemical localization of anterior pituitary hormones in S-100 protein-positive cells in the rat pituitary gland

In the anterior and intermediate lobes of the rat pituitary gland, non-hormone-producing cells that express S-100 protein coexist with various types of hormone-producing cells and are believed to function as phagocytes, supporting and paracrine-controlling cells of hormone-producing cells and stem cells, among other functions; however, their cytological characteristics are not yet fully understood. Using a transgenic rat that expresses green fluorescent protein under the promoter of the S100β protein gene, we immunohistochemically detected expression of the luteinizing hormone, thyroid-stimulating hormone, prolactin, growth hormone and proopiomelanocortin by S-100 protein-positive cells located between clusters of hormone-producing cells in the intermediate lobe. These findings lend support to the hypothesis that S-100 protein-positive cells are capable of differentiating into hormone-producing cells in the adult rat pituitary gland.