四种阿片受体激动剂对大鼠腹腔巨噬细胞释放过氧化氢的影响

本实验观察了四种阿片受体亚型的激动剂对大鼠腹腔巨噬细胞(Mφ)释放过氧化氢(H_2O_2的影响。吗啡、β-内啡肽和κ受体激动剂NDAP能抑制Mφ释放H_2O_2。纳洛酮能翻转吗啡和β-内啡肽的这一作用,κ受体阻断剂nor-BNI能拮抗NDAP的作用。δ受体激动剂DADLE仅在高浓度时才抑制Mφ释放H_2O_2。以上结果表明,Mφ上可能存在若干类型阿片受体,其中μ、ε和κ受体对Mφ释放H_2O_2具有明显的调节作用。     

不同浓度吗啡对心肌动作电位的作用及其机制

用微电极技术研究不同浓度吗啡对豚鼠右心室乳头肌动作电位的作用及作用机制。低浓度吗啡(0.2—1.6 umol/L)使动作电位时程(APD)和有效不应期(ERP)缩短,呈剂量依赖性。此作用可被1μmol/L 纳洛酮、酚妥拉明,四乙胺和氯化铯阻断,但不能被异搏定阻断。高浓度吗啡(15—120μmol/L)则使 APD 和 ERP 延长,呈剂量依赖性,这作用不被1.2μmol/L纳洛酮阻断,但可被10μmol/L 纳洛酮、酚妥拉明、四乙胺、氯化铯和异搏定阻断。这些实验提示低浓度和高浓度的吗啡可能作用于不同的阿片受体亚型,低浓度吗啡的作用可能与钾通道有关,高浓度吗啡的作用可能与钾通道、钙通道或钙激活的钾通道有关。阿片受体的作用与α受体存在密切关系。     

Na~+、K~+离子通道阻滞剂对离体大鼠黄体细胞孕酮生成的影响

本工作用二种离子通道阻断剂四乙胺(TEA)和河豚毒素(TTX)来研究 Na~+、K~+通道的改变对大鼠黄体细胞孕酮生成的影响。10~(-3)mol/L 的 TEA 或 TTX 均使孕酮分泌量显著增加,而这种促进效应可被酪氨酸(Tyr)完全阻断。Tyr 对 TEA 或 TTX 与 hCG 联合所引起的孕酮分泌也有抑制作用。上述实验说明跨黄体细胞内外的 K~+和 Na~+浓度差与孕酮分泌有关。     

在空肠环肌检测到特异性阿片受体

阿片能神经是肠肌间神经丛的主要肽能神经元,含有丰富的内源性阿片样肽。最近,Bitar 等将豚鼠和人空肠环肌和纵肌分离,检测阿片受体的分布。作者采用甲啡肽、甲啡肽Arg~6-Phe~7、β-内啡肽、强啡肽-13及亮啡肽等5种阿片样肽收缩环肌和纵肌。当浓度在10~(-12)～10~(-5)mol/L 时,上述阿片样肽均可呈浓度     

二十一种氨基酸对hCG致大鼠黄体细胞孕酮生成作用的影响

本文选用PMSG-hCG预处理的未成年雌性大鼠卵巢黄体经DNA酶-胶原酶消化后,制成黄体细胞悬浮液。在黄体细胞悬浮液的培养管内,加入hCG100mIU/ml 100μl,同时加入三种浓度(0.02,0.2,2mmol/L)的二十一种氨基酸,充入95％O_2+5％CO_2,37℃孵育1.5h,用放射免疫分析方法测孕酮含量。结果表明:二十一种氨基酸中,只有酪氨酸、苏氨酸、丝氨酸可对抗hCG致孕酮生成作用。这三种氨基酸在结构上均具有羟基,都是蛋白质磷酸化的位点,据此推测:这三种氨基酸抗hCG致孕酮生成作用可能与干扰蛋白激酶的磷酸化有关。     

卵巢激素亦可作用于心脏受体

卵巢激素可调节脑、子宫、膀胱和肺内的β肾上腺素能受体;亦可作用于脑和膀胱的毒蕈碱样受体。因此推测,卵巢激素也可能作用于心脏的β肾上腺素能受体和毒蕈碱样受体。有人根据Baker和Potter介绍的方法制备心肌细胞膜,将膜的沉淀部分重新悬浮于60mol/L的磷酸钠钾缓冲液和50mmol/L的HEPES缓冲液中,分别用于毒蕈碱样受体和β肾上腺素能受体的结合测定。所得数据全部用微机处理,并通过直线回归分析和Scathacrd作图得到结合常数、解离常数和受体密度等分析参数。离体实验表明,所有的孕激素,只要浓度达到100μmol/L都可明显抑制~3H-二苯羟乙酸奎宁酯(~3H-QNB)与去卵巢大鼠心肌毒蕈碱样受体的结合,其中以孕酮和16α-甲基孕酮的作用最强,并呈现快速、可逆性的剂量依赖式抑制;而雌激     

不同阿片受体的特异性激活对黄体生成素和催乳素分泌的影响有差异

Leadem 等分别用μ,δ和κ三种阿片受体不同浓度的激动剂灌流去卵巢大鼠的第三脑室,结果发现:μ受体的激动剂 DAGO[Tyr-D-ALa-Gly-(Me)Phe-Glyol]在浓度为1μg/h 和10μg/h 时明显抑制黄体生成素(LH)的分泌作用;而对催乳素(PRL)的释放有显著加强作用。δ受体激动剂 DPDPE(D-Pen~2,     

孕酮和米非司酮对蒙古绵羊输卵管上皮细胞β-防御素mRNA表达的影响

β-防御素(β-defensin)在雌性动物生殖道广泛存在,起免疫防御作用.为了研究孕酮与雌性生殖道β-防御素mRNA表达的关系,本实验建立绵羊(Ovis aries)输卵管上皮细胞培养体系,添加不同浓度孕酮(10~(-6),10~(-7),10~(-8),10~(-9)和10~(-10) mol/L)和孕酮拮抗剂米非司酮后提取细胞总RNA,利用实时定量PCR测定β-防御素mRNA的相对表达量.结果显示,一定浓度的孕酮(10~(-6),10~(-7),10~(-8)和10~(-9) mol/L)对培养的输卵管上皮细胞β-defensin mRNA的表达有促进作用,且不同浓度的孕酮对β-defensin mRNA的表达的影响程度不同.米非司酮极显著抑制了孕酮诱导的β-defemin mRNA的表达.结果表明,孕酮通过与孕酮受体结合促进β-defensin mRNA的表达,推断雌性生理周期下孕酮可能通过作用于β-defensin等影响自身免疫.     

吗啡和血管紧张素Ⅱ对大鼠脑突触小体Ca~(2 )摄取的拮抗效应

行为实验已多次证明,脑室注射血管紧张素Ⅱ(AⅡ)可以对抗吗啡的镇痛作用,但机制不明。吗啡阻止神经末梢钙摄取被认为是其镇痛的机理之一,因此本工作研究了AⅡ和吗啡对大鼠脑突触小体~(45)Ca摄取的作用及相互关系。结果表明,吗啡(10~(-8)—10~(-6)mol/L)对~(45)Ca摄取有明显的抑制作用,10~(-7)mol/L时抑制41％(P<0.001),该效应可被吗啡受体阻断剂纳洛酮(10~(-6)mol/L)完全翻转。与吗啡的作用相反,AⅡ(10~(-8)—110~(-6)mol/L)可促进突触小体对~(45)Ca的摄取,10~(-7)mol/L时增加75％(P<0.001),该效应可被AⅡ受体阻断剂Saralasin(10~(-6)mol/L)完全翻转。将不同剂量的AⅡ(10~(-8)—10~(-6)mol/L)和10~(-8)mol/L吗啡与突触小体共同孵育,则吗啡抑制~(45)Ca摄取的作用被完全翻转。以上结果表明,AⅡ促进脑突触小体Ca~(2 )摄取,对抗了吗啡抑制Ca~(2 )摄取的作用,可能是AⅡ抗吗啡镇痛的机制之一。     

强啡肽A和CCK—8对大鼠脊髓突触小体摄取^45Ca的影响

为了探讨血管紧张素Ⅱ(AⅡ)和八肽胆囊收缩素(CCK-8)这两种肽的抗阿片作用机理,本实验中观察了三种阿片类物质(吗啡、强啡肽和 DPDPE)和两种抗阿片物质(AⅡ和 CCK-8)对大鼠脊髓突触小体摄取~(45) Ca 的影响。结果表明:(1)在脊髓腹柱突触小体上,10nmol/L—1μmol/L 的吗啡、强啡肽 A(Dyn A)和 DPDPE 对~(45)Ca 摄取均有较弱的抑制作用;(2)CCK-8在浓度高达lμmol/L 时对~(45)Ca 摄取有较弱的抑制作用;(3)AⅡ在浓度高达lμmol/L时也不影响腹柱突触小体摄取~(45)Ca;(4)在背柱的突触小体制备中,上述阿片物质中 Dyn A 对~(45)Ca 摄取有较强的抑制作用,并被 k 受体阻断剂 nor-BNI 所阻断。10和100nmol/L 的 CCK-8能翻转lμmol/L Dyn A 对~(45)Ca 摄取的抑制作用;(5)A Ⅱ不能翻转Dyn A 的抑制作用。以上结果提示,CCK-8阻断 Dyn A 抑制脊髓背柱突触小体摄取 Ca~(2+)的作用可能是其行为学中抗阿片作用的机理之一。AⅡ对脊髓 Ca~(2+)摄取和 Dyn A 抑制脊髓 Ca~(2+)摄取的作用皆无影响,与行为学中观察到的 AⅡ在脊髓内不能对抗阿片镇痛的现象一致,进一步说明 CCK-8和AⅡ拮抗阿片类物质对神经末梢 Ca~(2+)摄取的影响可能是其抗阿片作用的重要机理之一。     

内皮素—1对大鼠排卵前卵泡颗粒细胞产生孕酮的影响

本文用离体细胞体外孵育法研究了内皮素－１（ＥＴ）对大鼠排卵前卵泡颗粒细胞孕酮生成的影响及其作用机理。结果发现,ＥＴ能显著抑制ｈＣＧ刺激下的孕酮产生,抑制作用在浓度为１０－８ｍｏｌ／Ｌ时,即有显著意义（Ｐ＜０．０５,ｎ＝６）,至１０－７ｍｏｌ／Ｌ时则有非常显著的意义（Ｐ＜０．０１,ｎ＝６）;不同浓度ＥＴ（１０－７—１０－７ｍｏｌ／Ｌ）,对颗粒细胞基础孕酮的产生无明显影响。进一步研究表明,ＥＴ对ｈＣＧ刺激下孕酮生成的抑制作用,在用免抗人内皮素抗血清（ＥＴ－Ａ）１：１０００及ｃＡＭＰ后能明显被逆转。实验中还观察到,ＥＴ使颗粒细胞ＬＨ／ｈＣＧ受体数下降,亲和力降低。本文结果提示,ＥＴ可能为卵巢内的一种局部调节肽,通过作用于ＥＴ受体,干扰ＬＨ／ｈＣＧ受体功能和ｃＡＭＰ生成而抑制颗粒细胞孕酮的产生。     

吗啡和血管紧张素II对大鼠脑突触小体Ca^2＋摄取的拮抗效应

Behavioral observations have repeatedly shown that the analgesic effect of morphine can be antagonized by intracerebroventricular injection of angiotensin I (A I), although mechanisms underlying the action were obscure. Since a prevention of Ca2+ uptake into the nerve terminals was considered as one of the mechanisms for morphine analgesia, we examined the effect of A I and morphine on the 45Ca uptake by rat brain synaptosomal preparations. Morphine of 10(-8)-10(-6) mol/L produced a dose-related suppression on synaptosomal 45Ca uptake, which was completely reversed by the opioid antagonist naloxone of 10(-6) mol/L. A I of 10(-8)-10(-6) mol/L, on the contrary, enhanced 45Ca uptake. This effect was totally abolished by saralasin, a A I antagonist, at 10(-6) mol/L. When synaptosomal preparations were incubated in a mixture of morphine (10(-6) mol/L) and A I (10(-8)-10(-6) mol/L), the effect of morphine was almost completely reversed. The results suggest that the distinct effect of A I may account for, at least in part, the antagonistic effect of A I on morphine analgesia.     

Morphine and Enkephalins Potently Inhibit [3H]Noradrenaline Release from Rat Brain Cortex Synaptosomes: Further Evidence for a Presynaptic Localization of μ-Opioid Receptors

Synaptosomes prepared from rat cerebral cortex and labeled with [3H]noradrenaline (NA) were superfused with calcium-free Krebs-Ringer-bicarbonate medium and exposed to 10 mM K+ plus 0.1 mM Ca2+ so that [3H]NA release was induced. 6,7-Dihydroxy-N,N-dimethyl-2-aminotetralin (TL-99) strongly inhibited synaptosomal K+-induced [3H]NA release (EC50 = 5-10 nM) by activating alpha 2-adrenoceptors. Release was also inhibited (maximally by 40-50%) by morphine (EC50 = 5-10 nM), [Leu5]enkephalin (EC50 = approximately 300 nM), [D-Ala2,D-Leu5]enkephalin (DADLE), and Tyr-D-Ala-Gly-(NMe)Phe-Gly-ol (DAGO) (EC50 values = approximately 30 nM). In contrast to the mu-selective opioid receptor agonists morphine and DAGO, the highly delta-selective agonist [D-Pen2,D-Pen5]enkephalin (1 microM) did not affect [3H]-NA release. Furthermore, the inhibitory effect of DADLE, an agonist with affinity for both delta- and mu-opioid receptors, was antagonized by low concentrations of naloxone. The findings strongly support the view that, like alpha 2-adrenoceptors, mu-opioid receptors mediating inhibition of NA release in the rat cerebral cortex are localized on noradrenergic nerve terminals.     

人早孕子宫蜕膜催乳素分泌的调节

子宫内膜蜕膜化对胚泡植入与妊娠维持是非常重要的。为探讨蜕膜化维持的调节机制 ,本文研究了妊娠早期人子宫蜕膜细胞催乳素 (PRL)分泌的调节。结果表明 :(1)孕酮显著地刺激PRL的分泌。 (2 )雌激素的作用与其浓度有关 ,生理浓度的雌激素对PRL分泌无明显影响 ,而高水平的雌激素抑制孕酮的刺激作用。合适的雌孕激素比例对蜕膜化的维持是必要的。 (3)RU486明显地抑制PRL的分泌 ,故认为孕酮的作用至少是部分通过受体介导的机制。 (4 )高浓度的cAMP (≥ 10 -5mol/L)显著增加PRL的分泌 ,cAMP信号系统可能在蜕膜化反应中发挥重要作用。     

C57BL/6J-bgJ (beige) mice: differential sensitivity in the tail flick test to centrally administered mu- and delta-opioid receptor agonists

The antinociceptive effects of two mu-opioid receptor agonists, morphine and [D-Ala2, MePhe4, Gly-ol5]enkephalin (DAGO), and a selective delta-receptor agonist, [D-Pen2, L-Pen5]enkephalin (DPLPE), were determined in C57BL/6J-bgJ (beige) and control mice (CRS-CDl and C57BL/6By) using a standard tail-flick assay. The antinociceptive response of C57BL/6J-bgJ mice to intracerebro-ventricularly administered morphine and DAGO was significantly reduced compared to controls, but there was no difference in the antinociceptive response to DPLPE. These results suggest that there is a genetic deficit of mu-opioid receptor number or a genetically-induced alteration in receptor function in regions of C57BL/6J-bgJ brains involved in antinociception, that delta-opioid receptors can mediate antinociception in mice, and that the C57BL/6J-bgJ strain may offer a practical new animal model for studying the function of opioid receptor subtypes.     

Na^＋,K^＋离子通道阻滞剂对离体大鼠黄体细胞...

Two ionic channel blockers, TEA and TTX, were used in the present investigation to test whether blocking of Na+, K+ ion channels would affect the production of progesterone by corpus luteum (CL) cells of rat. Both TEA (10(-3) mol/L) and TTX (10(-3) mol/L) increased progesterone production significantly after treatment. This effect of the blockers could be completely inhibited by tyrosine (Tyr). In addition, Tyr was capable of reversing the combined effect of TEA, TTX and hCG on progesterone secretion. It is suggested that the concentration gradient of Na+ and K+ across the CL cell membrane in experiments mentioned above is implicated in steroidogenesis.     

Opioid Control of the In Vitro Release of Cholecystokinin-Like Material from the Rat Substantia Nigra

Possible interactions between Met-enkephalin and cholecystokinin (CCK)-containing neurons in the rat substantia nigra were investigated by looking for the effects of various opioid receptor ligands and inhibitors of enkephalin-degrading enzymes on the K(+)-evoked overflow of CCK-like material (CCKLM) from substantia nigra slices. The delta-opioid agonists D-Pen2, D-Pen5-enkephalin (50 microM) and Tyr-D-Thr-Gly-Phe-Leu-Thr (DTLET; 3 microM) enhanced, whereas the mu-opioid agonists Tyr-D-Ala-Gly-MePhe-Gly-ol (DAGO; 10 microM) and MePhe3, D-Pro4-morphiceptin (PL 017; 10 microM) decreased, the K(+)-evoked release of CCKLM. By contrast, the kappa-opioid agonist U-50488 H (5 microM) was inactive. The stimulatory effect of DTLET could be prevented by the delta antagonist ICI-154129 (50 microM), but not by the mu antagonist naloxone (1 microM). Conversely, the latter drug, but not ICI-154129, prevented the inhibitory effect of DAGO and PL 017. A significant increase in CCKLM overflow was observed upon tissue superfusion with the peptidase inhibitors kelatorphan or bestatin plus thiorphan. This effect probably resulted from the stimulation of delta-opioid receptors by endogenous enkephalins protected from degradation, because it could be prevented by ICI-154129 (50 microM). Furthermore the peptidase inhibitors did not enhance CCKLM release further when delta-opioid receptors were stimulated directly by DTLET (3 microM). These data indicate that opioids acting on delta and mu receptors may exert an opposite influence, i.e., excitatory and inhibitory, respectively, on CCK-containing neurons in the rat substantia nigra.(ABSTRACT TRUNCATED AT 250 WORDS)     

乙酰胆碱对培养T细胞功能的作用

本文研究不同浓度（１０＾－１０－１０＾－４ｍｏｌ／Ｌ）乙酰胆碱（ＡＣｈ）对离体培养的大鼠脾脏Ｔ淋巴细胞增殖的影响,并探讨其作用机制。实验结果表明：１０＾－９－１０＾－４ｍｏｌ／Ｌ可显著增强Ｔ细胞由刀豆素Ａ（Ｃ－Ａ）诱导的增殖反应,以１０＾－７－１０＾－６ｍｏｌ／Ｌ时最强。淋巴细胞先用ＡＣｈ刺激１ｈ或者刺激１ｈ后洗弃ＡＣｈ,再用ＣｏｎＡ诱导６ｈ的Ｔ细胞的增殖。１０＾－７－１０－６ｍｏｌ／Ｌ阿托品可阻     

3H][D-Ala2,NMePhe4,Gly-ol5]-enkephalin (mu-opioid) binding in beige-J mice

Tritiated [D-Ala2,NMePhe4,Gly-ol5]-enkephalin ([3H]DAGO) was used to examine mu-opioid receptor number and mu-ligand binding in brain synaptic membranes (P2 fraction) from C57BL/6J-bgJ/bgJ (beige-J) mice, a strain with combined deficiencies in immunological function (resembling Chediak-Higashi syndrome) and analgesic response to mu-opioid agonists such as morphine and DAGO. As controls, white mice, beige-J littermates (normally responsive to mu-opioid agonists), and a known mu-deficient strain (CXBK) were also examined. Neither the KD (0.47 to 0.49 nM) nor the Bmax (153 to 168 fmol/mg protein) determined for beige-J mice was significantly different from values determined for littermates or white mice. In contrast, the Bmax of CXBK mice (66 fmol/mg protein) was clearly less than that of the other strains. The analgesic defect of beige-J mice, therefore, is not likely due to an insufficient number of mu-opioid receptors, as it presumably is in CXBK mice. Carbachol (200 micrograms/ml), which partly corrects the analgesic defect of beige-J mice, had no effect on [3H]DAGO binding either acutely in vitro or chronically ex vivo after administration to beige-J mice for three weeks. Hence, the analgesic defect of beige-J mice appears to be due to some defect in the mu-opioid receptor-effector coupling mechanism or to some endogenous substance that inhibits binding of mu-opioid ligands to otherwise functional receptors.