Abstract: Objective To compare the effects of nitroglycerine (NTG)， Verapamil(VP), papaverine(PA) and the mixed solution of Verapamil and nitroglycerine (VG) on relaxing function of human radial arteries. Methods The radial arteries of thirty patients were used during the operation of coronary artery bypass grafting (CABG). A short segment (1.0-1.5cm) of radial arteris were taken from the distal end of radial arteries of each patient and were cut into vascular rings, which were mounted in the organ bath chamber and then subject to a series of tests for vascular smooth muscle viability and endothelial integrity. The effects of five storage solutions on the relaxing function were evaluated by “OrganBath” technique. The five solutions included: (1) Ringer’ s solution (control group); (2) VP solution (VP group); (3) NTG solution (NTG group); (4) PA solution (PA group); (5) VG solution (VG group). First, challenged with phenylephrine (10-5mol/L), vasorelaxant effect of these drugs (effect onset and efficacy) was observed at different time point and resting tension was recorded. Second, after 30min preincubation with either verapamil, papaverine, phenoxybenzamine or VG mixture, potassium chloride (final concentration of 60mmol/L) was added in the organ bath chamber and then vasoconstriction was observed subsequently. Finally, after 30min pretreatment of different antispasmodic agent in the same way as described above, the vascular rings were mounted in organ bath chamber and challenged with phenylephrine(10-5mol/L). Vascular spasticity and vosospasm duration were observed at different time point which might provide guidance for optimal timing of clinical application. Results The radial arteries in VG, VP, NTG and PA solutions were relaxed in 11 min after vasospasm and there was no difference between them (Pgt;0.05). But during the initial three minutes，the relaxation effect of VG and NTG was significantly better than other two groups. Relaxation curve showed that the ability of vasodilatation of VG, NTG, VP and PA decreased in order. In the experiment about antivasospasm pretreatment of radial arteries, there was no difference between VG and VP group (Pgt;0.05 ), whose effects were better than NTG and PA group(Plt;0.05 ). After cold storage for 24h, VG and VP still could prevent vasospasm. But NTG and PA hardly had any function and there was no difference compared with the control group (Pgt;0.05 ). Conclusion Although in the final all these drugs could prevent and relieve vasospasm of radial arteries in the different level, it appeared that a combination of verapamil and nitroglycenn is more fit for treating radial artery during CABG operation than other drugs.
Objective To investigate the therapeutic effects of subconjunctival verapamil on outcome in an experimental model of traumatic proliferative vitreoretinopathy. Methods An experimental model of traumatic proliferative vitreoretinopathy was induced in pigme nt rabbits,which then were selected randomly to receive either subconjunctival verapamil injection treatment or a placebo injection(control)daily for 3 weeks.Animals were examined by indirect ophthalmoscopy at weekly intervals for 5 weeks. Eyes were enucleated for light microscopy 5 weeks later. Results Fifty-six percent(18 of 32)of the rabbits receiving subconjunctival verapamil injection had developed tractional retinal detachment,whereas eighty-one percent(26 of 32)of control animals had developed tractional retinal detachment(chi;2=4.655,P=0.031).The results of clinical examination and light microscopy didn't show evidence of toxicity between the verapamil treated animals and control animals. Conclusion Subconjunctival verapamil decreased the incidence of tractional retinal detachment due to traumatic proliferative vetreoretinopathy in this rabbit model.Verapamil at the dose used in this model has no evident toxicity on rabbit eyes.Further studies are needed to determine the doseresponse and efficacy of the drug. (Chin J Ocul Fundus Dis,1999,15:69-71)
目的 观察维拉帕米对兔脊髓缺血再灌注神经损伤的影响。 方法 选用健康兔30只，随机分为3组，A组为假手术组（只穿线不结扎），B组为缺血再灌注组（腹主动脉缺血30 min后，再灌注48 h），C组为维拉帕米组（0.2 mg/kg维拉帕米静脉注射后，腹主动脉缺血30 min，再灌注48 h）。对3组动物行神经功能评价并通过病理组织学观察神经元细胞的变化，以此评价维拉帕米对兔脊髓缺血再灌注神经损伤的保护作用。 结果 A组神经功能评价、神经元细胞的病理组织学观察均正常。B组神经功能出现明显障碍，神经元细胞形态异常。C组亦出现神经功能障碍，神经元细胞形态异常，但均较B组轻。 结论 应用维拉帕米可减轻因脊髓缺血再灌注造成的神经损伤。
ObjectiveIn order to evaluate that whether the P-glycoprotein-inhibitor verapamil (VPM) could effect the distribution of antiepileptic drug phenytoin (PHT) in a rat model of mesial temporal lobe epilepsy (MTLE).MethodsThe rat models of MTLE were induced by li-pilocarpine and were randomly divided into two groups (PHT group and VPM+PHT treatment group) to compare the PHT distribution in brain, liver and kidney. Brain dialysate samples were collected by microdialysis technology. And the analysis of samples for PHT concentration was performed by high performance liquid chromatography (HPLC). The comparisons were carried out by t test (or Wilcoxon test).ResultsIn VPM+PHT treatment group, 4 out of 9 rats were dead within 30 minutes after drug administration. The significantly decreased area under the curve (AUC) ratio of brain/plasma in VPM+PHT group was 0.11±0.06 when compared with PHT group 0.21±0.02 (t=3.237, P=0.025), while there were no significant differences in ratios of liver/plasma ［PHT (1.12±0.37) vs. VPM+PHT (0.99±0.27), Z=−0.490, P=0.624］ and kidney/plasma ［PHT (0.74±0.16) vs. VPM+PHT (0.49±0.26), t=1.872, P=0.103］ between two groups.ConclusionsThe P-glycoprotein-inhibitor VPM significantly decreased PHT level in brain of rat with MTLE.