RESUMO
Objective To investigate the effect of potassium channel blocker tetraethtylamine (TEA) on the proliferation and apoptosis of human laryngeal carcinoma cells (Hep-2) through the PI3K/Akt signaling pathway.Methods TEA acted on HEp-2.The methyl thiazolyl blue (MTT) method was used to determine the Hep-2 cell activity and the proliferation inhibition rate of TEA on Hep-2 was calculated;the Hoechest33258 staining was used to detect cell apoptosis,and the Hep-2 apoptosis rate was detected by flow cytometry (FCM) assay.Results After inoculation by 5,10,20 mmol/L TEA,the Hep-2 cell proliferation inhibition rate reached 12.573%,31.385% and 56.132%,respectively.After 96 h Hep-2 cell action,the cellular apoptosis rates were (41.64±2.67)%,(58.76±4.32)% and (72.65±6.54)% respectively,the inhibition rate and apoptosis rate in the TEA treating group were significantly higher than those in the non-TEA treating group,the differences were statistically significant (P<0.05).Conclusion TEA can inhibit the proliferation and in vivo growth of human laryngeal carcinoma cells and promotes the apoptosis of laryngeal cancer cells.
RESUMO
OBJECTIVE:To study the diastolic effect and mechanism of Hui medicine Hexin oil solution on isolated thoracic aortic vascular rings of rats,and provide reference for its treatment for cardiovascular diseases. METHODS:Thoracic aortic vascu-lar rings of rats were taken and then soaked in Kelvin's nutrient solution(K-H). Using 1×10-6 mol/L norepinephrine(PE)or 60 mmol/L potassium chloride (KCl) for inducing the contraction of vascular rings,biological signal acquisition and analysis system was used to determine the diastolic effect and mechanism of Hexin oil solution with concentrations of 0.0204,0.0408,0.0612, 0.0816,0.1020 mg/mL on vascular rings,and diastolic rate was calculated. After culturing vascular rings by 0.1 mmol/L nitric ox-ide synthase inhibitor L-nitro-arginine methyl ester (L-NAME),cyclooxygenase inhibitor indomethacin (INDO),and potassium ion channel blocker glibenclamide(Gli)for 20 min,the diastolic effects of above-mentioned 5 mass concentrations of Hexin oil so-lution on the contraction of vascular rings pre-contracted by PE were determined,and diastolic rate was calculated. The test was based on K-H solution as blank control. RESULTS:Compared with blank control,Hexin oil solution with concentration of 0.0204-0.1020 mg/mL had obvious diastolic effect on the contraction of vascular rings induced by PE and KCl (P<0.05 or P<0.01), showing concentration-dependent relationship. INDO pre-treatment can relieve the diastolic effect of Hexin oil solution on vascular rings pre-contracted by PE;and compared with blank control group,the diastolic rate had no statistical significance (P>0.05). While the pre-treatment of Gli,L-NAME did not affect the diastolic effect of Hexin oil solution on vascular rings pre-contracted by PE;and compared with blank control group,diastolic rate was obviously increased(P<0.05 or P<0.01). CONCLUSIONS:Hex-in oil solution can concentration-dependently conduct the relaxation of thoracic aortic vascular rings pre-contracted by PE,KCl. The mechanism may be associated with activation of cyclooxygenase pathway.
RESUMO
OBJECTIVE:To study the diastolic effect and mechanism of Hui medicine Hexin oil solution on isolated thoracic aortic vascular rings of rats,and provide reference for its treatment for cardiovascular diseases. METHODS:Thoracic aortic vascu-lar rings of rats were taken and then soaked in Kelvin's nutrient solution(K-H). Using 1×10-6 mol/L norepinephrine(PE)or 60 mmol/L potassium chloride (KCl) for inducing the contraction of vascular rings,biological signal acquisition and analysis system was used to determine the diastolic effect and mechanism of Hexin oil solution with concentrations of 0.0204,0.0408,0.0612, 0.0816,0.1020 mg/mL on vascular rings,and diastolic rate was calculated. After culturing vascular rings by 0.1 mmol/L nitric ox-ide synthase inhibitor L-nitro-arginine methyl ester (L-NAME),cyclooxygenase inhibitor indomethacin (INDO),and potassium ion channel blocker glibenclamide(Gli)for 20 min,the diastolic effects of above-mentioned 5 mass concentrations of Hexin oil so-lution on the contraction of vascular rings pre-contracted by PE were determined,and diastolic rate was calculated. The test was based on K-H solution as blank control. RESULTS:Compared with blank control,Hexin oil solution with concentration of 0.0204-0.1020 mg/mL had obvious diastolic effect on the contraction of vascular rings induced by PE and KCl (P<0.05 or P<0.01), showing concentration-dependent relationship. INDO pre-treatment can relieve the diastolic effect of Hexin oil solution on vascular rings pre-contracted by PE;and compared with blank control group,the diastolic rate had no statistical significance (P>0.05). While the pre-treatment of Gli,L-NAME did not affect the diastolic effect of Hexin oil solution on vascular rings pre-contracted by PE;and compared with blank control group,diastolic rate was obviously increased(P<0.05 or P<0.01). CONCLUSIONS:Hex-in oil solution can concentration-dependently conduct the relaxation of thoracic aortic vascular rings pre-contracted by PE,KCl. The mechanism may be associated with activation of cyclooxygenase pathway.
RESUMO
BACKGROUND:Potassium channel is the main ion channel to regulate vascular smooth muscle contraction and relaxation, and closely related with vascular tone. However, the reports about the mechanism of potassium channels in the body’s aging process are rare. OBJECTIVE:To investigate the effects of aging on the arterial ultrastructure and smooth muscle potassium channel reaction, and then to explore the possible mechanisms. METHODS:Sixteen healthy male Wistar rats were col ected, 19-month-old rats were assigned to the old group (n=8), 2-month-old rats were used as young group (n=8). The thoracic arteries were isolated and cut into rings to conduct contractility measurement in six rats of each group. The thoracic arteries were stimulated with specific calcium-activated potassium channel blocker tetraethylammonium, specific voltage-dependent potassium channel blocker 4-aminopyridine, specific ATP-sensitive potassium channel blocker glibenclamide, and specific inward rectifier potassium channel blocker BaCl 2 ultrastructure changes under electron microscope. , and then the arterial contractile response to the blockers were observed. The thoracic arteries of the remaining two rats in each group were taken to observe the arterial RESULTS AND CONCLUSION:Compared with the young group, the ultrastructures of the thoracic aortic endothelial cells and smooth muscle cells were changed in the old group;KCI induced the maximum thoracic aortic contractile tension, and then recovered to the baseline tension, and the recovery time in the old group was significantly longer than that in the young group;al the four kinds of blockers could increase vascular tone, and the tetraethylammonium and 4-aminopyridine induced thoracic aortic contractile response in the old group was significantly lower than that in the young group;there was no significant difference in vasoconstriction induced by glibenclamide and BaCl 2 . Aging can induce arterial ultrastructure changes and declination of vasodilatation capacity, which may partly due to the decreasing of the potassium channels function in smooth muscle cells, especial y the calcium-activated potassium channel and inward rectifier potassium channel.
RESUMO
Idiopathic optic neuritis (ION) is a common disorder in neuro-ophthalmology. It harms vision function seriously. However, there are a lots of controversy and confusion about its etiology, etiopathogenesis and outcome of treatments. Recently, potassium channel, such as stichodactyla helianthus peptide (ShK) and TRAM-34, was found to be involved in the immunopathogenesis of ION, and regulation of potassium channel provide a novel immunomodulatory therapy for ION. This paper reviewed the research advance of potassium channel in ION. It is expected to further clarify the pathogenesis and search for effective treatment.
RESUMO
This study was designed to evaluate the effects of calcium and potassium channel blockers on local anesthetics-induced vascular relaxation of isolated rat thoracic aorta. In the presence of lidocaine and bupivacaine, the aortic rings previously contracted with phenylephrine(10(-4)M) were slightly contracted at the beginning of the administration of local anesthetics. But in the presence of tetracaine, aortic rings were not contracted at the beginnings. Verapamil, diltiazem and nifedipine in concentration of 10(-9)M to 10(-5)M produced cumulative concentration-dependent vasorelaxation significantly in the aortic rings previously contracted with phenylephrine(10(-4)M). In the presence of lidocaine, bupivacaine and tetracaine, verapamil, diltiazem and nifedipine in concentration of 10(-9)M to 10(-5)M caused dose-dependent vasorelaxation in aortic rings significantly. Tetraethylammonium HCl(TEA) in concentration of 10(-9)M to 10(-5)M did not produce dose-dependent vasorelaxation but slight contraction showed at the beginning of the administration. In the presence of lidocaine, bupivacaine, TEA in concentration of 10(-9)M to 10(-5)M did not produce vasorelaxation remarkably. But in the presence of tetracaine, TEA in concentration of 10(-9)M to 10(-5)M produced cumuIative concentration-dependent vasorelaxation significantly. These findings suggest that local anesthetics, especially tetracaine, which interact with calcium and potassium channel bleckers, lead to blockade of the sodium and calcium channels as well as potassium channels.