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1.
P L Cohen J J Ellner E M Shevach 《Journal of immunology (Baltimore, Md. : 1950)》1977,118(6):2034-2039
Guinea pig spleen cells cultured together with peritoneal exudate lymphocytes (PEL) were found to generate large numbers of antibody-forming cells (AFC) in vitro in response to hapten-protein antigens. Neither cell type cultured alone yielded appreciable responses. Strain 13 or F1 (Strain 2 X Strain 13) lymphocytes, but not those from strain 2 animals, are able to respond to the genetically controlled antigen, DNP-guinea pig albumin (DNP-GPA). Antisera directed against responder (strain 13) parent Ia antigens selectively blocked the generation of AFC by F1 (strain 2 X strain 13) spleen-PEL mixtures in response to DNP-GPA. Both allogeneic (strain 2) and syngeneic macrophages functioned equally well in presentation of DNP-GPA to strain 13 lymphocytes. 相似文献
2.
铃蟾肽介导的豚鼠肠系膜下神经节非胆碱能迟慢兴奋性突触后电位 总被引:1,自引:0,他引:1
应用细胞内记录技术,对铃蟾肽(bombesin,BOM)在豚鼠离体肠系膜下神经节(inferior mesenteric ganglion,IMG)非胆碱能兴奋性突触传递中的作用进行了研究。重复电刺激突触前结肠神经,有74.3%(52/70)IMG细胞可诱发迟慢兴奋性突触后电位(ls-EPSP)。在可引出ls-EPSP的细胞中,22%(4/18)细胞同时对BOM和SP敏感。用BOM持续灌流IMG,可明显抑制对BOM敏感细胞的ls-EPSP,对BOM不敏感细胞的ls-EPSP则无影响,且BOM受体与SP受体间无交叉脱敏。BOM受体阻断剂tyr^4[D-phe^12]bombesin能明显可逆性地抑制BOM敏感细胞的ls-EPSP和去极化,但对BOM不敏感细胞则无影响。研究结果提示,BOM可能是介导豚鼠IMG细胞ls-EPSP的一种递质。 相似文献
3.
S Dokita W R Morgan M A Wheeler M Yoshida J Latifpour R M Weiss 《Life sciences》1991,48(25):2429-2436
Electrical field stimulation induced a relaxation response in female rabbit urethral smooth muscle strips precontracted with phenylephrine. The relaxation response was inhibited by tetrodotoxin, but not by atropine, propranolol, or hexamethonium. The relaxation response thus results from stimulation of inhibitory non-adrenergic, non-cholinergic nerves. The electrically induced relaxation response was inhibited by an inhibitor of nitric oxide biosynthesis, NG-nitro-L-arginine. This inhibition was overcome by addition of a precursor of nitric oxide, L-arginine. An inhibitor of soluble guanylate cyclase, methylene blue, reduced the relaxation response, and a selective cyclic GMP phosphodiesterase inhibitor, M & B 22948, potentiated the relaxation response. These data indicate that agents which affect the biosynthesis of nitric oxide are associated with the urethral relaxation response evoked by electrical field stimulation, and that cyclic GMP may mediate the relaxation response. 相似文献
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The effect of repeated weekly antigen challenges by aerosol on bronchopulmonary responses to ACh, histamine, neurokinin A or atropine-resistant (NANC) component of vagal stimulation, has been studied in guinea pigs. Bronchospastic responses were measured in anaesthetized animals, 7 days after the last challenge with antigen (or vehicle). No difference was observed between control and antigen challenged guinea pigs in their responsiveness to acetylcholine (1-300 mumol kg-1 i.v.) or histamine (1-300 mumol kg-1 i.v.). On the other hand, amplitude of bronchospasm induced by neurokinin A (1-3 mumol kg-1 i.v.) or NANC vagal stimulation (20 Hz, 1 msec, 10 V, trains of 5-20 sec) was significantly increased in guinea pigs previously challenged with antigen, as compared to controls. These results suggest that repetitive antigen exposure in sensitized guinea pigs generates an increase in the responsiveness to exogenously administered or endogenously released tachykinins, at a time when no generalized hyperresponsiveness to other spasmogens could be observed. 相似文献
6.
Kantar A Oggiano N Giorgi PL Coppa GV Gabbianelli R Bruni S Cutrona FM Fiorini R 《Mediators of inflammation》1994,3(7):S21-S24
The effect of nedocromil sodium on the plasma membrane fluidity of polymorphonuclear leukocytes (PMNs) was investigated by measuring steady-state fluorescence anisotropy of 1-[4-trimethylammonium-phenyl]-6-phenyl- 1,3,5-hexatriene (TMA-DPH) incorporated in the membrane. Our results show that nedocromil sodium 300 muM significantly decreased membrane fluidity of PMNs. The decrease in membrane fluidity of PMNs induced by fMLP was abolished in the presence of nedocromil sodium. These data suggest that nedocromil sodium interferes with the plasma membranes of PMNs and modulates their activities. 相似文献
7.
The innervation of the rat anococcygeus muscle has been investigated ultrastructurally following fixation with a modified chromaffin reaction for the demonstration of biogenic amines (Tranzer and Richards, 1976). Three types of nerve profiles were revealed: (1) 60-70% of the profiles are adrenergic; (2) less than 5% of the profiles appear to be cholinergic; (3) up to 40% of the profiles are distinguished by the presence of a characteristically high proportion of electron-opaque, chromaffin-negative vesicles, 85-110 nm in diameter. This third type of profile was not affected by 6-OHDA, and is considered to represent the non-adrenergic, non-cholinergic inhibitory innervation of this tissue. Because of the morphological similarity of this nerve type, apart from the smaller vesicle size, to classical peptidergic nerve endings, they have been termed "small p-type" (sp-type). These results are discussed in relation to a previous report describing only two types of nerve profiles in this tissue (Gillespie and Lüllmann-Rauch, 1974). 相似文献
8.
Fiocchi A Signoroni P Bruni P Galeone M Decet E Bogacki S 《Mediators of inflammation》1994,3(7):S43-S47
The purpose of this study was to evaluate whether nedocromil sodium benefits urban asthmatic children showing seasonal bronchial hyper-reactivity to ultrasonic nebulization of distilled water (UNDW). A prospective, randomized, placebo-controlled, parallel-group, double-blind study was carried out at the outpatient pulmonology service at a tertiary-care teaching hospital. Twelve children living in Milan, who were 7-17 years of age, who were SPT and RAST-negative to perennial allergens, who were suffering from episodic asthma, and showing seasonal bronchial hyper-reactivity to UNDW during winter, participated in this study. All the children received either placebo or nedocromil sodium, 4 mg every 6 h for 6 weeks. Spirometry and UNDW challenge were done at the following times: day-7; day 0; day 1; day 7; day 14; day 28; day 42. No differences were found in the basal spirometric parameters, which were normal in both nedocromil and placebo groups. Bronchial reactivity to UNDW was found to be significantly decreased in the group treated with nedocromtl starting from day 7. It is therefore concluded that nedocromil sodium can reverse bronchial hyper-reactivity caused by seasonal factors such as cold, viral infections and atmospheric pollutants in children suffering from asthma. 相似文献
9.
1. Temperature-dependent properties of synaptic transmission were studied by recording orthodromic responses of the population spike and excitatory postsynaptic potential in CA1 pyramidal neurons of guinea pig hippocampal slices.2. Increasing the temperature of the perfusing medium from 30 to 43°C resulted in a decrease in the amplitude of the population spike (A-PS) and a reduced slope of the excitatory postsynaptic potential (S-EPSP). Bath application of the -aminobutyric acid receptor antagonist, picrotoxin, or a change in the calcium concentration of the perfusate did not affect the A-PS during heating.3. Increasing the strength of the synaptic input to that eliciting a PS with an amplitude 50, 75, or 100% of maximal at 30°C resulted in a significant increase in the A-PS during the middle phase of hyperthermia (35–39°C).4. The long-term potentiation (LTP) induced at either 30 or 37°C showed the same percentage increase in both the amplitude of the population spike and the S-EPSP after delivery of a tetanus (100 Hz, 100 pulses) to CA1 synapses.5. The results of the present study, therefore, indicate that the decrease in CA1 field potential was linearly related to the temperature of the slice preparation, while LTP was induced in these responses during heating from 30 to 37°C. 相似文献
10.
Endomorphins 1 and 2 reduce relaxant non-adrenergic,non-cholinergic neurotransmission in rat gastric fundus 总被引:6,自引:0,他引:6
It is now well established that opioids modulate cholinergic excitatory neurotransmission in the gastrointestinal tract. The aim of the present study was to characterize a possible effect of endomorphins on nonadrenergic, noncholinergic (NANC) relaxant neurotransmission in the rat gastric fundus in vitro. The drugs used in the experiments were the endogenous mu-opioid receptors (MORs) endomorphin 1 and 2 and the mu-opioid receptor antagonist CTAP (D-Phe-Cys-Tyr-D-Trp-Arg-Thr-Pen-Thr-NH2). CTAP left the basal tonus and the spontaneous activity of the preparation unchanged. Electrical field stimulation (EFS) under NANC conditions at frequencies ranging from 0.5 to 16 Hz caused a frequency-dependent relaxant response on the 5-hydoxytryptamine (5-HT) (10(-7) M) precontracted smooth-muscle strip. Both endomorphin 1 and endomorphin 2 significantly reduced this relaxation in a concentration-dependent manner. Endomorphin 1 proved to be more potent in reducing the relaxant responses. The endomorphin effects were significantly reversed by the MOR antagonist CTAP. CTAP itself did not influence the EFS-induced relaxation. In summary, these data provide evidence that the endogenous MOR agonists endomorphin 1 and 2 can reduce nonadrenergic, noncholinergic neurotransmission in the rat gastric fundus smooth muscle via a pathway involving MORs. The physiological relevance of these findings remains to be established, since the data presented suggest that the endomorphins act as neuromodulators within NANC relaxant neurotransmission. 相似文献
11.
The actions of peptide YY (PYY) were studied in longitudinal organ-bath preparations of the guinea pig intestine. PYY induced concentration-dependent (10(-9)-5 x 10(-8) M) relaxations of tissue from the duodenum, jejunum, ileum, and colon. These responses were unaffected by adrenergic blockade and atropine treatment but could be prevented by tetrodotoxin. The pharmacology of PYY actions in segments of the small and large intestine indicated the involvement of intrinsic nonadrenergic, noncholinergic inhibitory neurones in the relaxation response to this peptide. All tissues could be made tachyphylactic to PYY without affecting their ability to respond to the direct acting muscle relaxants ATP or papaverine. Moreover, nicotinic ganglion stimulated relaxations and cholinergic nerve-mediated contractions were also unaffected. These results show applied PYY to have potent neurogenic actions in the guinea pig intestine with some similarities to PYY actions in the rat intestine. 相似文献
12.
Currents through DPI 201-106 modified single sodium channels have been measured in cell-free inside-out patches from guinea-pig ventricular myocytes. Single-channel conductance and reversal potential of the sodium channel have been calculated at different intracellular sodium concentrations [( Na+]i) from microscopic I-V curves, which were obtained by application of linear voltage ramps. The relation between the reversal potential and [Na+]i could be fitted with a modified Goldman-Hodgkin-Katz equation with a relative permeability for K+ over Na+ ions of 0.054. The zero-current conductance of the Na channel as a function of [Na+]i shows a plateau value at low Na concentrations, and increases in a sigmoidal manner at higher concentrations. It is concluded that the Na channel can carry outward currents and that its conductance depends on [Na+]i. 相似文献
13.
P Portincasa G Baldassarre G Palmieri G Palasciano 《Bollettino della Società italiana di biologia sperimentale》1989,65(9):869-875
Calcitonin (CT) is a 32 amino acidic polypeptide hormone which has been found in almost all species and whose effects are mainly concerned with calcium and phosphorous homeostasis. Three preparations are employed for therapeutic uses: salmon (sCT), porcine (pCT) and human CT (hCT). The sCT is the most powerful one and in human volunteers a strong relaxing effect has been shown on gallbladder (GB) basal volume and emptying in response to a meal, intraduodenal instillation of a liquid meal and i.v. cholecystokinin (CCK) infusion. Our study was aimed at investigating if a direct sCT effect could be demonstrated on smooth muscle strips from guinea pig GBs "in vitro" (organ bath). Isometric contractions were measured in response to maximal doses of acetylcholine (ACh: 10(-4) M), KCl (80 mM) and cholecystokinin octapeptide (CCK-OP: 10(-6) M), in absence and in presence of four doses of sCT (1 x 10(-9), 1 x 10(-8), 1 x 10(-7) and 1 x 10(-6) M). sCT did not affect the initial strip basal tone. ACh, CCK-OP and KCl caused, as expected, a powerful contraction of the strips, but no effect was shown when each of the sCT doses was administered before ACh (1.28+ 0.69 SEM without sCT vs 1.28g+ 0.69 with sCT; n = 6) and CCK-OP (1.46g+ 0.19 without sCT vs 1.46g+ 0.19 with sCT; n = 8) or 5 min after the induced KCl contraction. On the basis of these preliminary results, we conclude that no evidence of a direct sCT effect was found on guinea pig GBs when considering either basal smooth muscle tone or isometric contraction in response to ACh, KCl and CCK-OP. Further studies are therefore required to clarify the influence of CT on GB dynamics in vivo and to elucidate its the physiological significance. 相似文献
14.
F Mulè R Serio A Postorino 《Archives internationales de physiologie et de biochimie》1990,98(4):149-154
In rat isolated duodenal segments, adenosine induced, in the presence of atropine and guanethidine, a dose-dependent, long-lasting (about 20 s), tetrodotoxin (TTX)-resistant relaxation both in endoluminal pressure and in isometric tension. Electrical field stimulation (EFS) induced, in the presence of atropine and guanethidine, a TTX-sensitive short-lasting (about 6 s) relaxation followed by a sustained rebound contraction. Theophylline, a P1 receptor antagonist, at the concentration of 100 microM caused a marked inhibition of the adenosine-induced relaxation, while the EFS-induced relaxation was not modified. Our results suggest that adenosine induces relaxation of the rat duodenal smooth muscle acting on P1 receptors localized at muscular level. However, differences in the morphology and in the sensitivity to theophylline between adenosine- and EFS-induced relaxation ruled out adenosine as neurotransmitter of the non-adrenergic, non-cholinergic inhibitory system. 相似文献
15.
The smooth muscle of thoracic aorta from guinea pig sensitized with egg albumin (EA) produced an anaphylactic contraction when it was exposed to EA. Experiments were performed to evaluate stress effects on the anaphylactic contraction in guinea pig aortic rings. Two types of stressors were used as immunosuppressor stimuli: physical restraint and shaking of the animals. Both stressors diminished the amplitude of the Schultz-Dale contraction in aortic rings from sensitized guinea pig. The shake stress stimulus interrupted several times during each session induced higher immunosuppression in animals in which the active sensitization and the stress sessions began the same day. Severe restraint stress, prior to active immunization, also suppressed significantly the anaphylactic response. The Schulz-Dale reaction in guinea pig aorta seems to be a valuable technique to study the stress effects on the anaphylactic response. 相似文献
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M. F. Shuba I. A. Vladimirova T. O. Ermakova N. Jurkiewicz A. Jurkiewicz 《Neurophysiology》1998,30(4-5):208-212
Non-adrenergic non-cholinergic (NANCh) inhibitory synaptic potentials in smooth muscle cells (SMC) of the gastrointestinal
tract are of a complex transmitter and ion nature. A blocker of ATP receptors, suramin, blocks the fast component, while a
blocker of NO synthase, L-NOARG, blocks the slow component of NANCh inhibitory synaptic potentials. In the presence of both
suramin and L-NOARG, SMC respond to stimulation of the intramural plexus by generating a low-amplitude hyperpolarization,
and VIP is likely to be the transmitter for this effect. Low-conductance Ca2+-dependent potassium channels are involved in generation of the fast component of NANCh inhibitory synaptic potentials, and
these channels are effectively blocked by apamin. The slow component of this potential is generated by high-conductance Ca2+-dependent potassium channels. In the presene of both apamin and L-NOARG (or charibdotoxin), SMC respond to intramural stimulations
with non-cholinergic excitatory synaptic potentials, and ATP application evokes depolarization. Both effects are blocked by
suramin. In the presence of apamin, noradrenaline also evokes depolarization in SMC, and this effect, similarly to hyperpolarization
under normal conditions, is blocked by phentolamine. Our studies allow us to suggest that in smooth muscles of the gastrointestinal
tract there are two types of synaptic transmission: the excitatory cholinergic, adrenergic, and ATP-ergic transmission and
the inhibitory adrenergic, ATP-ergic, NO-ergic, and VIP-ergic transmission. 相似文献
19.
胍基丁胺在离体豚鼠乳头肌的电生理效应 总被引:2,自引:0,他引:2
应用细胞内微电极技术,观察了胍基丁胺(agmatine,AGM)对豚鼠乳头肌细胞的电生理效应。结果表明:(1)AGM浓度依赖地缩短正常乳头肌动作电位的时程;(2)对部分去极化的乳头肌,AGM(1mmol/L)除缩短动作电位时程外,还抑制动作电位零相最大上升速度,并降低其幅值和超射值;(3)预先应用一氧化氮合酶抑制剂LNAME(05mmol/L),不能影响AGM(1mmol/L)的电生理效应;(4)预先应用咪唑啉受体(imidazolinereceptor,IR)和α2肾上腺素能受体(alpha2adrenergicreceptor,α2AR)拮抗剂idazoxan(01mmol/L),则可完全阻断AGM(1mmol/L)的电生理效应。以上结果提示,AGM对乳头肌的电生理效应似由α2AR和IR介导,并与胞浆内Ca2+减少有关。 相似文献