BACKGROUND: Procyanidins is a kind of polyphenol compounds in regnum vegetable, which is composed of different quantities of catechin and epicatechin. Studies show that procyanidins plays a role on protecting vascular endothelium, scavenging free radicals, resisting platelet aggregation, and reducing capillary permeability. Thus, procyanidins has obviously functions of reducing blood pressure, anti-oxidant activity, anti-edema, preventing coronary heart disease and atherosclerosis.
OBJECTIVE: To study the vasorelaxant effect of procyanidins on pulmonic rings and its mechanisms.
METHODS: Rabbit thoracic pulmonary arteries were isolated. Pre-contracted with noradrenalin (1×10-6 mol/L) and their responses to different concentrations of procyanidins (0.625, 1.25, 2.5 mg/L) were investigated. After removal of the endothelium of pulmonary artery smooth muscle, the effects of different signaling pathway inhibitors on procyanidins-induced relaxation, including nitric oxide synthase inhibitor Nω-Nitro-L-arginine (1×10-4 mol/L), methylene blue (1×10-5 mol/L), prostaglandin synthase inhibitor indomethacin (1×10-5 mol/L) and blockage of the adrenergicβ-receptor propranolol (1×10-5 mol/L), were also assessed.
RESULTS AND CONCLUSION: (1) Procyanidins did not change the resting tension of rabbit’s pulmonic rings, but caused an obvious dose-dependent relaxation in 1×10-6 mol/L noradrenalin-precontracted pulmonic rings (r=0.69, P < 0.001). (2) The relaxant effect of procyanidins was significantly reduced by removal of endothelium or by treatment with either Nω-Nitro-L-arginine or methylene blue, but not by treatment with prostaglandin synthase inhibitor or blockage of the adrenergic β-receptor. (3) Procyanidins (20 mg/L) dropped the dose-effect curves of noradrenalin, KCl and on pulmonic rings denuded endothelium. Moreover, affinity index of noradrenalin, KCl and CaCl2 decreased (P < 0.01). (4) Procyanidins also inhibited the vasoconstriction caused by noradrenalin in the first phase, but had no impact on the constriction induced by CaCl2 in the second phase. (5) Procyanidins has an endothelium-dependent vasorelaxation on isolated rabbit’s pulmonic rings, which is possibly mediated by nitric oxide/cyclic guanosine monophosphate pathways. Procyanidins blocked receptor-operated and voltage-dependent calcium channels to reduce intracel ular Ca2+, and induced vasorelaxation.

0.05) respectively. CONCLUSION: DMR can relax isolated rabbit pulmonary artery on the basis of endothelium-dependent and may involve in nitric oxide (NO), but is not related to blockage of receptor-operated and voltage-dependent calcium channels.

BACKGROUND: Recent research has shown that Gastrodia elata Bl (GEB) has a cardiovascular protective effect and relaxes blood vessels with important therapeutic implication to treat coronary heart disease and hypertension. However, the mechanism is still unclear.OBJESTIVE: To study the effect of the water decoction of GEB on noradrenaline (NA) or KC1 precontracted aortic rings and the possible mechanisms.DESIGN: A grouping observational experiment of animal tissue in vitro.SETTING: Department of Physiology, North Sichuan Medical College.MATERIALS: Twelve health New Zealand、White rabbits (2.5-3.0 kg, 7-8 months, SPF, either gender) were provided by the Experimental Animal Center, North Sichuan Medical College. The water decoction of GEB was prepared by Huirentang Drugstore and diluted into 10%, 20%, 40%and 80% solution. The following drugs were used: Nω-nitro-L-arginine (L-NNA, Sigma, USA); Methylene blue (MB, Merck, Germany); Acetylcholine (ACh) and Propranolol (Prop) (The Second Beijing Pharmaceutical Company, China); Indomethacin (Indo, Jingsu Taicang Pharmaceutical Company, China).METHODS: The experiment was performed in the Institute of Materia Medica, North Sichuan Medical College between January 2006 and January 2007. Rabbit smooth muscles of aortic rings were isolated and precontracted with NA. The thoracic aortic rings were treated with GEB with cumulative concentrations of 1.0,2.0,4.0,8.0 and 16g/L respectively. The aortic tings were treated with one of the following signaling inhibitors for 15 minutes, including 1×104mol/L L-NNA, 1×10-5mol/L MB, 1×10-5mol/L Indo and 1×10-5mol/L Prop. The changes of tension in aortic rings were recorded using a force transducer and processed by BL-410 Experimental System of Biological Function. The aortic rings were incubated with 8g/L GEB followed by the NA and KCl dose response experiments.MAIN OUTCOME MEASURES: Blood vessel tension ex vivo.RESULTS: GEB did not change the resting tension of rabbit aortic rings, but GEB treatment resulted in an obvious relaxation in NA-precontracted aortic rings (r=0.85, t=18.45, P＜0.01) and the relaxant effect was dose-dependent. The relaxant effect of GEB was significantly reduced by removal of endothelium and by treatment with 1×10-4mol/L nitric oxide synthase inhibitor L-NNA (1×10-4mol/L), or 1×10-5mol/L guanylyl cyclase inhibitor methylene blue (1×10-5mol/L MB), but not by treatment with prostaglandin synthase inhibitor of blockage of the adrenergic β-receptor (1×10-5mol/L Prop). In addition, GEB (8g/L) decreased the dose response curves of aortic rings to NA or KCl in the absence of endothelial cells, and changed the PD2 values for NA from (6.90±0.93)mol/L in control group to[(5.61±0.70)mol/L, t=2.41, P＜0.05] and for KCl from (1.53±0.55) mmol/L in control group to (1.10±0.25)mmol/L, t=3.82, P＜0.05] respectively.CONCLUSION: GEB can relax isolated rabbit aorta not only in an endothelium-dependent, nitric oxide involved manner, but also is related to blockage of receptor-operated and potential-dependent calcium channels.

BACKGROUND:Aconitum carmichaeli Debx (ACD) is the tuberous root of Aconium carmicgaekum, used as cardiotonic to restore yang for the treatment of colapse and shock, to warm the kidney and reinforceyang, and to expel cold and promote the flow ofyang-qi. Studies have found that ACD has obviously cardiotonic, antihypertensive, vasodilatory, analgesic, anti-inflammatory and toxic effects. OBJESTIVE: To observe the vasodilatory effects of a water decoction of ACD on rabbit’s aorta rings and its mechanism. METHODS:Rabbits aorta arteries were isolated, pre-contracted with noradrenaline (10-6 mol/L) and their responses to different concentrations of ACD (0.5, 1.0, 2.0, 4.0, 8.0 g/L) were investigated. The effects of removal of vascular endothelium and different signaling pathway inhibitors (Nω-nitro-L-arginine: 1×10-4 mol/L, methylene blue: 1×10-5 mol/L, indomethacin: 1×10-5 mol/L, propranolol: 1×10-5 mol/L) on ACD-induced vasodilation were also assessed. RESULTS AND CONCLUSION:ACD could not change the resting tension of rabbit aortic rings, but ACD treatment resulted in an obvious relaxation in narodrenaline-precontracted aortic rings and the relaxant effect was dose-dependent. The vasodilatory effect of ACD was significantly reduced by removal of endothelium, 1×10-4 mol/L Nω-nitro-L-arginine and 1×10-5 mol/L methylene blue but not reduced by indomethacin and propranolol. In addition, 4 g/L water decoction of ACD did not decrease the dose-response curves of artery rings to narodrenaline or KCl in the absence of endothelial cels. ACD can relax isolated rabbit’s aorta, which may be related to endothelium-released nitric oxide, but has no significant relevance with receptor-operated and voltage-dependent calcium channels.

OBJECTIVETo study the vasodilation effects of the Total alkali Sophora alopecuroids L (TASa) on rabbit thoracic aortic rings in vitro and the possible mechanisms.

METHODRabbit aortic rings were isolated and precontracted with noradrenaline (NA) and then were divided into six groups including control group, TASa group, TASa + 1 x 10(-5) mol x L(-1) indomethacin (Indo), TASa + 1 x 10(-5) mol x L(-1) propranolol (Prop), TASa + 1 x 10(-10 mol x L(-1) N(omega)-nitro-L-arginine (L-NNA), TASa + removal of endothelium. The vasodilation effects of TASa were investigated. In addition, the thoracic aortic rings were pre-treated with TASa (40 mg x L(-1)) and then the thoracic aortic rings were treated with cumulative NA (110(-8)-110(-5) mol x L(-1)), KCl (6.3-100 mmol x L(-1)) or CaCl2 (110(-5)-110(-2) mol x L(-1)). The dose response curves of aortic rings were recorded.

RESULTTASa can relax isolated rabbit aorta and has an obvious concentration-dependent relaxation (r = 0.94, P < 0.01). The relaxant effect of TASa was no significant reducing by removal of endothelium and by treatment with L-NNA, Indo or Prop. In addition, TASa can decrease the dose response curves of aortic rings to NA, KCl or CaCl2.

CONCLUSIONThe vasodilation effects of TASa are related to not only inhibition of intracellular calcium release, but also reduction to calcium flow to the interior of the cell with blockage of calcium channels.

Alkalies ; pharmacology ; Animals ; Aorta, Thoracic ; drug effects ; physiology ; Female ; In Vitro Techniques ; Male ; Muscle, Smooth, Vascular ; drug effects ; physiology ; Myocardial Contraction ; drug effects ; Plant Extracts ; chemistry ; pharmacology ; Rabbits ; Sophora ; chemistry ; Vasodilator Agents ; chemistry ; pharmacology

OBJECTIVETo study the vasorelaxant effect of procyanidin (PC) extracted from grape seeds on rabbit thoracic pulmonic rings in vitro.

METHODRabbits thoracic pulmonic rings were isolated, pre-contracted with noradrenalin (NA) and their responses to different concentrations of PC were investigated. The effects of endothelium and different signaling pathway inhibitors on PC-induced relaxation, including nitric oxide synthase inhibitor N(omega)-nitro-L-arginine (L-NNA), methylene blue (MB), prostaglandin synthase inhibitor indomethacin (Indo) and blockage of the adrenergic beta-receptor propranolol (Prop), were also assessed.

RESULTPC change the resting tension of rabbit's pulmonic rings but caused an obvious dose-dependent relaxation in 1 x 10(-6) mol x L(-) NA precontracted pulmonic rings (r = 0.69, P < 0.01). The relaxant effect of PC was significantly reduced by removal of endothelium or by treatment with either 1 x 10(-4) mol x L(-1) L-NNA or 1 x 10(-5) mol L(-1) MB, but not by treatment with prostaglandin synthase inhibitor or blockage of the adrenergic beta-receptor. In addition, PC (20 mg x L(-1)) dropped the dose-effect curves of NA, KCl and respectively on pulmonic rings denuded endothelium. PC can also inhibit the vasoconstriction caused by NA in the first phase, but has no impact on the constriction induced by CaCl2 in the second phase.

CONCLUSIONPC has an endothelium-dependent vasorelaxation on isolated rabbit's pulmonic rings, which is possibly mediated by nitric oxide (NO) pathways and blockage of receptor operated and voltage dependent calcium channels.

Animals ; Disease Models, Animal ; Female ; Heart Diseases ; drug therapy ; physiopathology ; Humans ; In Vitro Techniques ; Male ; Proanthocyanidins ; pharmacology ; Pulmonary Artery ; drug effects ; physiopathology ; Rabbits ; Random Allocation ; Vasodilation ; drug effects ; Vasodilator Agents ; pharmacology

The mixed evaluation system uses the network platform as a carrier to construct a dynamic evaluation model that spans time and space between online and offline, between individuals and teams. Mixed evaluation system of physiology was performed for two years, and the process evaluation and the summative evaluation in the mixed evaluation system showed a good correlation, and the students' learning ability and learning effect showed consistency with the evaluation results. Practice has proved that the mixed evaluation system not only optimizes the traditional evaluation system, but also fully expands the five principles of formative evaluation; however, while reflecting the advantages of the network platform, it also exposes the defects of insufficient supervision of the network platform. Thus, we should further improve the mixed evaluation system of physiology.