Objectives To investigate the effects of β2-adrenergic antagonist on cytosolic Ca^2 + ([Ca^2+ ]i) in ventricular myocytes from infarcted rat heart. Methods A ligature was placed around left anterior descending co...Objectives To investigate the effects of β2-adrenergic antagonist on cytosolic Ca^2 + ([Ca^2+ ]i) in ventricular myocytes from infarcted rat heart. Methods A ligature was placed around left anterior descending coronary artery of rat hearts. Rats in the control group were sham-operated. Cardiomyocytes were dissociated at two, four, eight weeks after myocardial infarction (MI) and [Ca^2+]i was measured via fura-2 fluorescence. The response of cardiomyocytes to isoproterenol in presence or absence of betal-adrenergic antagonist atenolol, beta2-adrenergic antagonist ICI118, 551 or non-selective β1, 2- adrenergic antagonists propranolol was examined. Results The followings were found that ICI 118, 551 had no significant effects on the rise of [Ca^2+]i induced by isoproterenol in normal ventricular myocytes (P 〉 0.05), ICI118, 551 only significantly attenuated the rise of [Ca^2+]i induced by isoproterenol at four weeks and eight weeks after MI (24.5%±5.7% vs 57.8% ± 13.2%, P〈 0.01; 12.2%±7.9% vs 44.6%±11.3%, P〈 0.01). Atenolol had suppressive effects only in the control group and the post-MI group of two weeks (P 〈 0.05), and propranolol had suppressive effects in the control and all the three post-MI groups (P 〈 0.01). Conclusions Beta2-adrenergic antagonist ICI118, 551 may exert negative effects on Ca^2+ overload initiated by sympathetic stimulation after MI.展开更多
Central nervous system(CNS)trauma,including traumatic brain injury and spinal cord injury,has a high rate of disability and mortality,and effective treatment is currently lacking.Previous studies have revealed that ne...Central nervous system(CNS)trauma,including traumatic brain injury and spinal cord injury,has a high rate of disability and mortality,and effective treatment is currently lacking.Previous studies have revealed that neural inflammation plays a vital role in CNS trauma.As the initial enzyme in neuroinflammation,cytosolic phospholipase A_(2)(cPLA2)can hydrolyze membranous phosphatides at the sn-2 position in a preferential way to release lysophospholipids andω3-polyunsaturated fatty acid dominated by arachidonic acid,thereby inducing secondary injuries.Although there is substantial fresh knowledge pertaining to cPLA2,in-depth comprehension of how cPLA2 participates in CNS trauma and the potential methods to amelio rate the clinical res ults after CNS trauma are still insufficient.The present review summarizes the latest understanding of how cPLA2 participates in CNS trauma,highlighting novel findings pertaining to how cPLA2 activation initiates the potential mechanisms specifically,neuroinflammation,lysosome membrane functions,and autophagy activity,that damage the CNS after trauma.Moreover,we focused on testing a variety of drugs capable of inhibiting cPLA2 or the upstream pathway,and we explored how those agents might be utilized as treatments to improve the results following CNS trauma.This review aimed to effectively understand the mechanism of cPLA2 activation and its role in the pathophysiological processes of CNS trauma and provide clarification and a new referential framework for future research.展开更多
AIM: To investigate the fluid shear stress induced changes of [Ca^2+]i in neutrophils in pancreatic microcirculation of experimental acute pancreatitis (AP).METHODS: Wistar rats (n = 36) were randomized into three gro...AIM: To investigate the fluid shear stress induced changes of [Ca^2+]i in neutrophils in pancreatic microcirculation of experimental acute pancreatitis (AP).METHODS: Wistar rats (n = 36) were randomized into three groups. A model of AP was established by subcutaneous injection of caerulein. Low-shear 30 viscometer was used to provide steady fluid shear stress on separated neutrophils. The mean fluorescent intensity tested by flow cytometry was used as the indication of [Ca2+]i quantity.RESULTS: Under steady shear, cytosolic [Ca^2+]i showed biphasic changes. The shear rate changed from low to high, [Ca^2+]i in different groups decreased slightly and then increased gradually to a high level (P<0.05). A close correlation was observed between the cytosolic [Ca^2+]i level and the alteration of fluid shear stress in regional microcirculation of AP. CONCLUSION: The increase of [Ca^2+]i is highly related to the activation of neutrophils, which contributes to neutrophil adhesion to endothelium in the early phase of AP. The effect of fluid shear stress on [Ca^2+]i may play a crucial role in pancreatic microcirculatory failure of AP.展开更多
Voltage-gated Na+ channel (Nav channel) scorpion toxins are classified as α- and β-neurotoxins. Ts5 (α-neurotoxin) and Ts1 (β-neurotoxin) from Tityus serrulatus venom (TsV) interact with Nav channels, increasing N...Voltage-gated Na+ channel (Nav channel) scorpion toxins are classified as α- and β-neurotoxins. Ts5 (α-neurotoxin) and Ts1 (β-neurotoxin) from Tityus serrulatus venom (TsV) interact with Nav channels, increasing Na+ influx and activating voltage-dependent Ca2+ channels. This study aimed to investigate the effect of TsV, Ts1 and Ts5 on the cytosolic Ca2+ concentration ([Ca2+]C) in rat aortic smooth muscle cells. Toxins were isolated by ion exchange chromatography (Ts1) followed by RP-HPLC (Ts5). The rat aortic smooth muscle cells were isolated in Hanks buffer pH 7.4 and loaded with 5 μmol/L of Fura-2AM (45 minutes at 37℃), in order to measure [Ca2+]C by fluorescence of Fura-2/AM (ratio 340/380 nm). The fluorescence was measured in one single cell (excitation: 340 and 380 nm;emission: 510 nm). TsV (100 and 500 mg/mL) and its toxins Ts1 and Ts5 (50 and 100 mg/mL each) led to a concentration-dependent increase in [Ca2+]C. Tetrodotoxin (1 mmol/L), a Nav channel blocker, and verapamil (1 mmol/L), a voltage-operated Ca2+ channel blocker, inhibited the increase in [Ca2+]C induced by TsV (500 mg/mL). In conclusion, TsV and its toxins induce a concentration-dependent increase in [Ca2+]C that probably occurs through interaction with Nav channels, thus inducing depolarization and consequent Ca2+ influx. This assumption is based on the fact that this effect is inhibited by tetrodotoxin and verapamil, showing a direct action of TsV toxins on aorta smooth muscle cells.展开更多
文摘Objectives To investigate the effects of β2-adrenergic antagonist on cytosolic Ca^2 + ([Ca^2+ ]i) in ventricular myocytes from infarcted rat heart. Methods A ligature was placed around left anterior descending coronary artery of rat hearts. Rats in the control group were sham-operated. Cardiomyocytes were dissociated at two, four, eight weeks after myocardial infarction (MI) and [Ca^2+]i was measured via fura-2 fluorescence. The response of cardiomyocytes to isoproterenol in presence or absence of betal-adrenergic antagonist atenolol, beta2-adrenergic antagonist ICI118, 551 or non-selective β1, 2- adrenergic antagonists propranolol was examined. Results The followings were found that ICI 118, 551 had no significant effects on the rise of [Ca^2+]i induced by isoproterenol in normal ventricular myocytes (P 〉 0.05), ICI118, 551 only significantly attenuated the rise of [Ca^2+]i induced by isoproterenol at four weeks and eight weeks after MI (24.5%±5.7% vs 57.8% ± 13.2%, P〈 0.01; 12.2%±7.9% vs 44.6%±11.3%, P〈 0.01). Atenolol had suppressive effects only in the control group and the post-MI group of two weeks (P 〈 0.05), and propranolol had suppressive effects in the control and all the three post-MI groups (P 〈 0.01). Conclusions Beta2-adrenergic antagonist ICI118, 551 may exert negative effects on Ca^2+ overload initiated by sympathetic stimulation after MI.
基金supported by the National Natural Science Foundation of China,No.82072192(to KLZ)Public Welfare Technology Research Project of Zhejiang Province,No.LGF20H150003(to KLZ)+1 种基金the Natural Science Foundation of Zhejiang Province,Nos.LY17H060009 and Y21H060050(both to WFN)Wenzhou Science and Technology Bureau Foundation,No.Y20210438(to KLZ)。
文摘Central nervous system(CNS)trauma,including traumatic brain injury and spinal cord injury,has a high rate of disability and mortality,and effective treatment is currently lacking.Previous studies have revealed that neural inflammation plays a vital role in CNS trauma.As the initial enzyme in neuroinflammation,cytosolic phospholipase A_(2)(cPLA2)can hydrolyze membranous phosphatides at the sn-2 position in a preferential way to release lysophospholipids andω3-polyunsaturated fatty acid dominated by arachidonic acid,thereby inducing secondary injuries.Although there is substantial fresh knowledge pertaining to cPLA2,in-depth comprehension of how cPLA2 participates in CNS trauma and the potential methods to amelio rate the clinical res ults after CNS trauma are still insufficient.The present review summarizes the latest understanding of how cPLA2 participates in CNS trauma,highlighting novel findings pertaining to how cPLA2 activation initiates the potential mechanisms specifically,neuroinflammation,lysosome membrane functions,and autophagy activity,that damage the CNS after trauma.Moreover,we focused on testing a variety of drugs capable of inhibiting cPLA2 or the upstream pathway,and we explored how those agents might be utilized as treatments to improve the results following CNS trauma.This review aimed to effectively understand the mechanism of cPLA2 activation and its role in the pathophysiological processes of CNS trauma and provide clarification and a new referential framework for future research.
基金Supported by the National Natural Science Foundation of China,No.39770722 and the Key Project of National Outstanding Youth Foundation of China,No.39925032
文摘AIM: To investigate the fluid shear stress induced changes of [Ca^2+]i in neutrophils in pancreatic microcirculation of experimental acute pancreatitis (AP).METHODS: Wistar rats (n = 36) were randomized into three groups. A model of AP was established by subcutaneous injection of caerulein. Low-shear 30 viscometer was used to provide steady fluid shear stress on separated neutrophils. The mean fluorescent intensity tested by flow cytometry was used as the indication of [Ca2+]i quantity.RESULTS: Under steady shear, cytosolic [Ca^2+]i showed biphasic changes. The shear rate changed from low to high, [Ca^2+]i in different groups decreased slightly and then increased gradually to a high level (P<0.05). A close correlation was observed between the cytosolic [Ca^2+]i level and the alteration of fluid shear stress in regional microcirculation of AP. CONCLUSION: The increase of [Ca^2+]i is highly related to the activation of neutrophils, which contributes to neutrophil adhesion to endothelium in the early phase of AP. The effect of fluid shear stress on [Ca^2+]i may play a crucial role in pancreatic microcirculatory failure of AP.
基金supported by grants from Fundacao de Amparoa Pesquisa do Estado de Sao Paulo(FAPESP)Conselho Nacional de Desenvolvimento Cientifico e Tecnologico(CNPq).
文摘Voltage-gated Na+ channel (Nav channel) scorpion toxins are classified as α- and β-neurotoxins. Ts5 (α-neurotoxin) and Ts1 (β-neurotoxin) from Tityus serrulatus venom (TsV) interact with Nav channels, increasing Na+ influx and activating voltage-dependent Ca2+ channels. This study aimed to investigate the effect of TsV, Ts1 and Ts5 on the cytosolic Ca2+ concentration ([Ca2+]C) in rat aortic smooth muscle cells. Toxins were isolated by ion exchange chromatography (Ts1) followed by RP-HPLC (Ts5). The rat aortic smooth muscle cells were isolated in Hanks buffer pH 7.4 and loaded with 5 μmol/L of Fura-2AM (45 minutes at 37℃), in order to measure [Ca2+]C by fluorescence of Fura-2/AM (ratio 340/380 nm). The fluorescence was measured in one single cell (excitation: 340 and 380 nm;emission: 510 nm). TsV (100 and 500 mg/mL) and its toxins Ts1 and Ts5 (50 and 100 mg/mL each) led to a concentration-dependent increase in [Ca2+]C. Tetrodotoxin (1 mmol/L), a Nav channel blocker, and verapamil (1 mmol/L), a voltage-operated Ca2+ channel blocker, inhibited the increase in [Ca2+]C induced by TsV (500 mg/mL). In conclusion, TsV and its toxins induce a concentration-dependent increase in [Ca2+]C that probably occurs through interaction with Nav channels, thus inducing depolarization and consequent Ca2+ influx. This assumption is based on the fact that this effect is inhibited by tetrodotoxin and verapamil, showing a direct action of TsV toxins on aorta smooth muscle cells.