To observe microwave induced dynamic pathological changes in the sinus nodes, wistar rats were exposed to 0, 5, 10, 50 mW/cm^2 microwave. In 10 and 50 mW/cm^2 groups, disorganized sinoatrial node cells, cell swelling,...To observe microwave induced dynamic pathological changes in the sinus nodes, wistar rats were exposed to 0, 5, 10, 50 mW/cm^2 microwave. In 10 and 50 mW/cm^2 groups, disorganized sinoatrial node cells, cell swelling, cytoplasmic condensation, nuclear pyknosis, and anachromasis, swollen, and empty mitochondria, and blurred and focally dissolved myofibrils could be detected from 1 to 28 d, while reduced parenchymal cells, increased collagen fibers, and extracellular matrix remodeling of interstitial cells were observed from 6 to 12 months. In conclusion, 10 and 50 mW/cm^2 microwave could cause structural damages in the sinoatrial node and extracellular matrix remodeling in rats.展开更多
Objective: To study the effect of simulated ischemia-reperfusion (I/R) on If of sinoatrial node (SAN) cells and the intervention of KATP channel opener Pinacidil. Methods: The SAN cells of the neonatal rats were detac...Objective: To study the effect of simulated ischemia-reperfusion (I/R) on If of sinoatrial node (SAN) cells and the intervention of KATP channel opener Pinacidil. Methods: The SAN cells of the neonatal rats were detached and purified 2 d before the experiment. The experimental animals were randomly divided into the control group, group of simulated I/R, group intervened with KATP channel opener Pinacidil (P+ I/R) and group intervened with KATP channel blocking agent 5-HD (5-HD + P + I/R & 5-HD + I/R). The If density of each group was measured by technique of routine whole cell patch clamp and multiple-catheter perfusion system and the If activated curve in each group was drawn. Results: ①Under different directive potentials, the If density of the SAN cells in I/R group increased significantly, compared with that in the control group ( P < 0.01); that in P + I/R group decreased significantly, compared with that in I/R group ( P < 0.01); the If density values in 5-HD + P + I/R group and 5-HD + I/R group increased significantly, compared with that in P + I/R group, but showed no significant difference with that in I/R group. ②Compared with that in the control group, the If activated curve of the SAN cells moved rightwards under ultimate activating potential, half of which was from - 108.0 ± 12.4 to - 89.5 ± 7.2 mV ( P <0.01); compared with that in I/R group, If activated curve of the SAN cells moved leftwards under ultimate activating potential, half of which was the range from -99.5± 10.8 mV (P<0.05); KATP channel blocking agent 5-HD could block the effect of Pinacdil on If activated curve. Conclusion: KATP channel opener Pinacidil can antagonize the effect of simulated I/R on the If of SAN cells, which may be beneficial to the maintenance of the relative stability of ion steady state and electrophysiological activities under condition of simulated I/R.展开更多
Junctional rhythm is usually seen in the clinic with different causes.We report a case of bicuspid aortic valve accompa-nied by sinoatrial node dysfunction.The junctional escape beat could accelerate with physiologica...Junctional rhythm is usually seen in the clinic with different causes.We report a case of bicuspid aortic valve accompa-nied by sinoatrial node dysfunction.The junctional escape beat could accelerate with physiological needs and provided for the normal needs of daily life when dysfunction of the sinoatrial node occurred,which provides a new way for the treatment of sinoatrial node dysfunction.Our fi ndings could be potentially signifi cant for identifying causes and choos-ing appropriate treatment strategies by using ECG monitoring in the clinic in the future.展开更多
Objective: To study the effect of KATp channel opener and its possible mechanism on the sinoatrial node cells of neonatal rats which were cultured under simulated ischemia-reperfusion. Methods: Freshly isolated sinoat...Objective: To study the effect of KATp channel opener and its possible mechanism on the sinoatrial node cells of neonatal rats which were cultured under simulated ischemia-reperfusion. Methods: Freshly isolated sinoatrial node (SAN) cells of neonatal rats were purified and cultured for 2 d, and then they were randomly divided into the control, simulated ischemia-reperfusion group (I/R group) , group intervened with KATp channel opener pinacidil (P + I/R group), KATP Channel blocking agent 5-HD (5-HD + I/R group) , and group with the 2 agents at same time (5-HD + P + I/R group) . The survival rate of cells was measured by flow cytometry and the content of intracellular calcium in the cells of each group was detected with laser confocal microscopy. Results: ① The survival rate of SAN cells in I/R group [ (51. 79±6. 28)% ] was remarkably significantly lower than in control [ (95. 08±10. 48)% ] (P < 0.001), and very significantly lower than in P + I/R group [ (63. 77±5. 35) % ] (P<0.01), however, those of 5-HD + P + I/R group [(52. 88±6. 25)% ] and 5-HD+I/R group [ (53. 16±5. 35)% ] was significantly lower compared with that in P + I/R group (P <0. 01) ; ② When the average fluorescence intensity of sinoatrial node cells in the control was regarded as 100% , the relative fluorescence intensities of each group were: ( 374±52) % in I/R group, significantly higher than that of control (P <0. 01) ; ( 162±20)% in P + I/R group, declining significantly than that of I/R group (P<0.01); (385?6)% in 5-HD+ P + I/R group and (379±44)% in 5-HD + I/R group, increasing significantly than that of I/R group (P<0.01). Conclusion: ① Simulated ischemia-reperfusion can significantly reduce the survival rate of SAN cells, and can also lead to the overload of intracellular calcium in them.② KATp channel opener, pinacidil, exerts protective effect on the cells under simulated ischemia-reperfusion, which may be associated with the decrease of intracellular calcium loading in them.展开更多
文摘To observe microwave induced dynamic pathological changes in the sinus nodes, wistar rats were exposed to 0, 5, 10, 50 mW/cm^2 microwave. In 10 and 50 mW/cm^2 groups, disorganized sinoatrial node cells, cell swelling, cytoplasmic condensation, nuclear pyknosis, and anachromasis, swollen, and empty mitochondria, and blurred and focally dissolved myofibrils could be detected from 1 to 28 d, while reduced parenchymal cells, increased collagen fibers, and extracellular matrix remodeling of interstitial cells were observed from 6 to 12 months. In conclusion, 10 and 50 mW/cm^2 microwave could cause structural damages in the sinoatrial node and extracellular matrix remodeling in rats.
基金Supported by National Natural Science Foundation of China (No.30070314)
文摘Objective: To study the effect of simulated ischemia-reperfusion (I/R) on If of sinoatrial node (SAN) cells and the intervention of KATP channel opener Pinacidil. Methods: The SAN cells of the neonatal rats were detached and purified 2 d before the experiment. The experimental animals were randomly divided into the control group, group of simulated I/R, group intervened with KATP channel opener Pinacidil (P+ I/R) and group intervened with KATP channel blocking agent 5-HD (5-HD + P + I/R & 5-HD + I/R). The If density of each group was measured by technique of routine whole cell patch clamp and multiple-catheter perfusion system and the If activated curve in each group was drawn. Results: ①Under different directive potentials, the If density of the SAN cells in I/R group increased significantly, compared with that in the control group ( P < 0.01); that in P + I/R group decreased significantly, compared with that in I/R group ( P < 0.01); the If density values in 5-HD + P + I/R group and 5-HD + I/R group increased significantly, compared with that in P + I/R group, but showed no significant difference with that in I/R group. ②Compared with that in the control group, the If activated curve of the SAN cells moved rightwards under ultimate activating potential, half of which was from - 108.0 ± 12.4 to - 89.5 ± 7.2 mV ( P <0.01); compared with that in I/R group, If activated curve of the SAN cells moved leftwards under ultimate activating potential, half of which was the range from -99.5± 10.8 mV (P<0.05); KATP channel blocking agent 5-HD could block the effect of Pinacdil on If activated curve. Conclusion: KATP channel opener Pinacidil can antagonize the effect of simulated I/R on the If of SAN cells, which may be beneficial to the maintenance of the relative stability of ion steady state and electrophysiological activities under condition of simulated I/R.
基金supported by a grant from the Guidance Project of the Xiamen Medical and Health Program(3502Z20199007).
文摘Junctional rhythm is usually seen in the clinic with different causes.We report a case of bicuspid aortic valve accompa-nied by sinoatrial node dysfunction.The junctional escape beat could accelerate with physiological needs and provided for the normal needs of daily life when dysfunction of the sinoatrial node occurred,which provides a new way for the treatment of sinoatrial node dysfunction.Our fi ndings could be potentially signifi cant for identifying causes and choos-ing appropriate treatment strategies by using ECG monitoring in the clinic in the future.
基金Supported by National Natural Science Foundation of China (No. 30070314)
文摘Objective: To study the effect of KATp channel opener and its possible mechanism on the sinoatrial node cells of neonatal rats which were cultured under simulated ischemia-reperfusion. Methods: Freshly isolated sinoatrial node (SAN) cells of neonatal rats were purified and cultured for 2 d, and then they were randomly divided into the control, simulated ischemia-reperfusion group (I/R group) , group intervened with KATp channel opener pinacidil (P + I/R group), KATP Channel blocking agent 5-HD (5-HD + I/R group) , and group with the 2 agents at same time (5-HD + P + I/R group) . The survival rate of cells was measured by flow cytometry and the content of intracellular calcium in the cells of each group was detected with laser confocal microscopy. Results: ① The survival rate of SAN cells in I/R group [ (51. 79±6. 28)% ] was remarkably significantly lower than in control [ (95. 08±10. 48)% ] (P < 0.001), and very significantly lower than in P + I/R group [ (63. 77±5. 35) % ] (P<0.01), however, those of 5-HD + P + I/R group [(52. 88±6. 25)% ] and 5-HD+I/R group [ (53. 16±5. 35)% ] was significantly lower compared with that in P + I/R group (P <0. 01) ; ② When the average fluorescence intensity of sinoatrial node cells in the control was regarded as 100% , the relative fluorescence intensities of each group were: ( 374±52) % in I/R group, significantly higher than that of control (P <0. 01) ; ( 162±20)% in P + I/R group, declining significantly than that of I/R group (P<0.01); (385?6)% in 5-HD+ P + I/R group and (379±44)% in 5-HD + I/R group, increasing significantly than that of I/R group (P<0.01). Conclusion: ① Simulated ischemia-reperfusion can significantly reduce the survival rate of SAN cells, and can also lead to the overload of intracellular calcium in them.② KATp channel opener, pinacidil, exerts protective effect on the cells under simulated ischemia-reperfusion, which may be associated with the decrease of intracellular calcium loading in them.
