哈乐在良性前列腺增生伴急性尿潴留中的应用

目的 :探讨α1A肾上腺素能受体阻滞剂哈乐 (tamsulosin)对良性前列腺增生 (BPH)伴急性尿潴留病人的治疗作用。方法 :对 72例BPH伴急性尿潴留病人采用随机、对照研究 ,分为治疗组和对照组。病人均行保留导尿 ,口服抗生素治疗。治疗组加用哈乐 0 .4mg ,1次 /d ,连续服用 3次。 72h后拔除导尿管。　结果 :拔除导尿管后 4 4 % (32 / 72 )的病人能自行排尿。有效率治疗组为 6 1% (2 2 / 36 ) ,对照组为 2 8% (10 / 36 ) ,两组比较差异有显著性 (P <0 .0 1)。　结论 :对BPH伴急性尿潴留应用哈乐治疗 ,可提高早期拔除导尿管后病人自行排尿的成功率 ,且疗效与前列腺体积大小无关。     

Effect of the NK3 receptor antagonist, talnetant, on rectal sensory function and compliance in healthy humans

Visceral hypersensitivity is important in the pathophysiology of irritable bowel syndrome and thus a target for modulation in drug development. Neurokinin (NK) receptors, including NK(3) receptors, are expressed in the motor and sensory systems of the digestive tract. The aim of this study was to compare the effects of two different doses (25 and 100 mg) of the NK(3) receptor antagonist, talnetant (SB223412) with placebo on rectal sensory function and compliance in healthy volunteers studied at two centres. Rectal barostat tests were performed on 102 healthy volunteers, randomized to receive either oral talnetant 25 or 100 mg or placebo over 14-17 days. Studies were performed on three occasions: day 1 immediately prior to 1st dose, day 1 4 h postdose, and after 14- to17-day therapy. Compliance, and pressure thresholds for first sensation, urgency, discomfort and pain were measured using ascending method of limits, and sensory intensity ratings for gas, urgency, discomfort and pain determined during four random phasic distensions (12, 24, 36 and 48 mmHg). Talnetant had no effect on rectal compliance, sensory thresholds or intensity ratings compared with placebo. In general, the results obtained at the two centres differed minimally, with intensity scores at one centre consistently somewhat lower. At the doses tested, talnetant has no effect on rectal compliance or distension-induced rectal sensation in healthy participants.     

Effects of adrenergic and cholinergic antagonists on diameter of nasolacrimal drainage system

Background To determine the effect of an adrenergic and a cholinergic antagonist on the diameter of the lumen of the nasolacrimal drainage system. Methods The asymptomatic side of 38 patients (29 women, nine men) with unilateral stenosis/obstruction of the nasolacrimal drainage system was studied. The tear meniscus height (TMH) of the asymptomatic side was normal, and the lacrimal drainage system was patent as revealed by dacryocystography. The nasolacrimal drainage system of the asymptomatic side was infused with 100 μl of 0.01% bunazosin hydrochloride, a selective α-1 adrenergic antagonist, or 100 μl of 0.4% tropicamide, a muscarinic and cholinergic antagonist. Dacryocystography was performed to determine the diameter of the lumen of the nasolacrimal drainage system before and after the antagonists. Results Bunazosin reduced the diameter of the lumen significantly, and the changes were more marked in the nasolacrimal duct (NLD), especially the middle and the lower regions. The diameter of the lumen of the lacrimal sac was not changed significantly. In contrast, tropicamide did not cause any significant change in the diameter of the lumen of the nasolacrimal drainage system. Conclusions The alterations of the size of the lumen of the nasolacrimal drainage system, especially the NLD, by an adrenergic antagonist suggest that the lumen diameter is under continuous sympathetic tone, and the parasympathetic tone is weak. This study has not received any financial support.     

Pharmacological characterization of the receptor mediating the adrenergic inhibition of responses to substance P in the cingulate cortex

The excitatory responses of neurones in the anterior cingulate cortex of the rat to iontophoretically applied substance P (SP) are reduced by noradrenaline (NA) applied iontophoretically or released from noradrenergic pathways. In order to determine the receptor involved in this inhibitory effect we have studied the effects of a number of receptor-specific adrenergic agonists and antagonists on responses of cingulate neurones to SP in rats anaesthetized with chloral hydrate. Low iontophoretic currents (0-15 nA) of NA, adrenaline and the beta-agonist, clenbuterol, all strongly reduced responses to SP. Isoprenaline was also effective but less consistently so, although problems were experienced with its iontophoretic release from micropipettes. The alpha 1-agonists, phenylephrine and methoxamine were also able to reduce responses to SP. However, this reduction required higher iontophoretic currents (15-60 nA) and was associated with depressant effects on baseline firing rate. The alpha 2-agonist clonidine was only weakly active at high currents and this too was associated with depression of baseline firing. Similar weak effects were noted with dopamine. The inhibitory effects of NA on SP responses were convincingly blocked or reversed by the beta-antagonist, practolol, but not by the alpha 1-antagonist, prazosin. The reduction of SP responses by phenylephrine was also blocked by practolol but unaffected by prazosin. Finally, reduction of SP excitations by activation of the coeruleocortical pathway was also blocked by practolol applied iontophoretically to the cortical cells. These results are consistent with the hypothesis that the effect of NA on SP responsiveness in the cingulate cortex is mediated by beta-adrenoreceptors.     

球囊成形术后氯沙坦对兔血管内膜增殖及巨噬细胞表达的影响

目的　通过观察AT1受体的特异性拮抗剂氯沙坦 (Losartan)对兔腹主动脉球囊成形术后内膜增殖和巨噬细胞表达的影响 ,探讨氯沙坦治疗血管再狭窄的机制。方法　采用内皮剥脱加高脂饮食 (含 1 5 %胆固醇 )喂养 8周制作兔腹主动脉粥样硬化膜型 ,然后对狭窄部位行球囊成形术。术后氯沙坦组给予氯沙坦 10mg·kg-1·day-1口服 ,对照组喂生理盐水。 4周后取腹主动脉行组织形态学观察 ,用免疫组织化学方法分析巨噬细胞。结果　对照组内膜厚度 /中膜厚度比值为 0 65± 0 17,氯沙坦组则减少为0 44± 0 11(P <0 0 1) ,对照组内膜面积 /中膜面积比值为 0 74± 0 16,氯沙坦组则减少为 0 5 4± 0 13(P <0 0 1)。氯沙坦组新生内膜中巨噬细胞数亦较对照组显著减少 (P <0 0 1)。结论　氯沙坦通过抑制AngⅡ的作用进而抑制巨噬细胞的浸润 ,抑制炎症反应 ,从而减轻再狭窄     

氨氯地平与尼群地平治疗高血压的多中心平行对照研究

采用多中心、随机、单盲、组间、平行对照的方法对488例原发性高血压患者进行氨氯地平或尼群地平4周治疗观察，显示氨氯地平的降压有效率为90．4％，较尼群地平显著为高。不良反应较少，安全性好。每日只需服药1次，剂量5～10mg，方便病人。     

Effects of naftidrofuryl oxalate, a 5HT2 antagonist, on neurotransmission and transduction systems in the gerbil hippocampus

We investigated the effects of age and naftidrofuryl oxalate (Naftidrofuryl), a 5-HT₂ antagonist, on neurotransmission and transduction systems in the gerbil hippocampus using quantitative autoradiography. [³H]Quinuclidinyl benzilate (QNB), [³H]cyclohexyl-adenosine (CHA), [³H]MK-801, and [³H]muscimol were used to label muscarinic acetylcholine, adenosine A1, N-methyl-d-aspartate (NMDA), and γ-aminobutyric acid-A (GABA_A) receptors, respectively. [³H]PN200-110 labeled L-type Ca²⁺ channels. [³H]Forskolin, [³H]cyclic adenosine monophosphate (cAMP), [³H]phorbol 12,13-dibutyrate (PDBu), and [³H]inositol 1,4,5-triphosphate (IP₃) were used to label adenylate cyclase, cAMP-dependent protein kinase, protein kinase C (PKC), and IP₃ receptors, respectively. Approximately 20% reductions in [³H]QNB, [³H]forskolin, and [³H]PDBu binding were observed in the hippocampus of 9-month-old gerbils in comparison with 5-week-old gerbils. Treatment with Naftidrofuryl (10 mg/kg, i.p., once a day for 7 days) ameliorated these reductions. No changes were found in [³H]CHA, [³H]MK-801, [³H]muscimol, [³H]PN200-110, [³H]cAMP, and [³H]IP₃ binding. The results suggest that Naftidrofuryl may have beneficial effects on the age-related alterations in signal transmission and transduction systems in the brain. Because the acetylcholine system, adenylate cyclase, and PKC are considered to be involved in learning and memory processes, the result may have clinical implications.     

Dose-dependent kinetics of the enantiomers of MK-571, an LTD4-receptor antagonist

Summary The disposition of the enantiomers of MK-571 (MK-0679 and L-668,018) following single i. v. doses of MK-571 (L-660,711) was studied in a three way cross-over study in 12 healthy male volunteers. Each volunteer received 75 mg, 300 mg and 600 mg i. v. doses of MK-571 at weekly intervals.The disposition of both enantiomers appeared dose-dependent, since the AUC increased disproportionately faster than the dose. The dose dependency was much more pronounced for L-668,018: its AUC increased 6-fold from the 75 to the 300 mg dose, 16-fold from 75 to 600 mg and 2.7 fold from 300 to 600 mg. For MK-0679, the corresponding increases in AUC were 4.8-, ll-, and 2.3 fold. Regardless of dose, the elimination of L-668,018 was more rapid than that of MK-0679.The disposition of MK-0679 needs to be investigated independently to detect any potential influence of L-668,018 on its disposition.     

Triflavin, an Arg-Gly-Asp containing snake venom peptide, inhibits aggregation of human platelets induced by human hepatoma cell line

Triflavin, an Arg-Gly-Asp (RGD)-containing peptide, purified from snake venom of Trimeresurus flavoviridis, inhibits human platelet aggregation through the blockade of fibrinogen binding to fibrinogen receptors associated with glycoprotein IIb/IIIa complex. In this report, we examined the effect of triflavin on tumor cells (human hepatoma J-5)-induced platelet aggregation (TCIPA) of heparinized platelet-rich plasma (PRP). ADP-scavenger agents, apyrase (10 U/ml) and creatine phosphate (5 mM)/creatine phosphokinase (5 U/ml) did not inhibit TCIPA while hirudin (5u/ml) completely inhibited it. J-5 cells initially induced platelet aggregation, then blood coagulation occurred. J-5 cells concentration-dependently shortened the recalcification time of normal as well as Factor VIII, IX-deficient human plasmas, while it was inactive at shortening the recalcification time of Factor VII-deficient plasma, suggesting J-5 cells induced platelet aggregation through activation of extrinsic pathway, leading to thrombin formation as evidenced by the amidolytic activity on S-2238 by expressing tissue factor-like activity. Triflavin inhibited TCIPA in a dose-dependent manner (IC₅₀, 0.02 μM). When compared on molar ratio, triflavin was approximately 30,000 times more potent than GRGDS (IC₅₀,0.58 mM). On the other hand, GRGES showed no significant effect on TCIPA, even its concentration was raised to 4 mM. Additionally, the monoclonal antibodies, raised against glycoprotein IIb/IIIa complex (i.e., 7E₃ and 10 E₅) inhibited J-5 TCIPA. In conclusion, we suggest the inhibitory effect of triflavin on J-5 TCIPA may be chiefly mediated by the binding of triflavin to the fibrinogen receptor associated with glycoprotein IIb/IIIa complex on platelet surface membrane.     

A VIP antagonist distinguishes VIP receptors on spinal cord cells and lymphocytes

Vasoactive intestinal peptide (VIP) is a neuropeptide which also interacts with cells of the immune system. The paucity of specific VIP receptor antagonists has hampered studies of possible receptor heterogeneity and of VIP function. To aid in achieving these goals, a new VIP antagonist, a hybrid between neurotensin and VIP, has been synthesized. This peptide interacted with VIP receptors on spinal cord cells with an affinity 10-fold greater than VIP itself. In contrast, 1000-fold higher concentrations of the antagonist were required to displace labeled VIP from its receptor on lymphoid cells as compared to VIP itself, suggesting VIP receptor heterogeneity between immune and spinal cord cells.