Objective： To investigate the expression of P2X receptors on rat intracardiac and paratracheal ganglion neurons. Methods： For preparation of intracardiac neurons, hearts were excised, the atria were separated and th...Objective： To investigate the expression of P2X receptors on rat intracardiac and paratracheal ganglion neurons. Methods： For preparation of intracardiac neurons, hearts were excised, the atria were separated and the medial region containing intracardiac ganglia was isolated and cut into pieces. For preparation of paratracheal neurons, the tracheas were removed and the superficial membranous layer containing paratracheal ganglia was rapidly isolated. Intracardiac and paratracheal ganglion neurons were dissociated after digestion by collagenase and trypsin. Whole-cell patch clamp recording was used to identify the pharmacological properties of P2X receptors in cultured neurons. Results：Neurons from these two ganglia responded to ATP with a rapidly activating, sustained inward current, αβ-meATP failed to evoke any re- sponses in paratracheal ganglion neurons while a few of intracardiac ganglion neurons responded to αβ- meATP with a tiny sustained inward current. ADP and UTP had no effect on intracardiac neurons. Lowering pH potentiated ATP responses in neurons from these two ganglia whereas increasing pH inhibited ATP responses. Co-application of Zn^2＋ potentiated ATP responses in intracardiac and paratracheal ganglion neurons. Conclusion： The receptor subtypes involved in intracardiac and paratracheal ganglia appear to be homomeric P2X2, while heteromeric P2X2/3 could not be completely excluded from intracardiac neurons.展开更多
The aim of this study was to compare six methods of detecting apoptosis induced by extracellular adenosine triphosphate (ATP) in human leukemic lymphocytes with purinergic P2Z receptors.These...The aim of this study was to compare six methods of detecting apoptosis induced by extracellular adenosine triphosphate (ATP) in human leukemic lymphocytes with purinergic P2Z receptors.These methods used were electron microscopy(EM), detection of internucleosomal DNA fragmentation by agarose gel electrophoresis, autoradiographic analysis of DNA fragmentation, in situ labeling of DNA strand breaks with fluorescein dUTP and exogenous terminal deoxynucleotidyl transferase (TUNEL), quantitation of 3 ends of DNA breaks by labeling with α 32 PdCTP(TdT assay), and quantitation of apoptotic cells with fluorescein annexin V using flow cytometry(FCA).We found EM and detection of DNA ladder pattern by agarose gel electrophoresis to be specific,but lacking in sensitivity. The combination of autoradiography and gel electrophoresis gave an increase in sensitivity of at least 50 fold although, of all the methods, the TdT assay was shown to be most sensitive. The four methods for quantifying apoptosis EM, FCA, TUNEL and TdT assay proved to be reliable and gave statistically similar results on apoptotic lymphocytes. These observations indicate it is essential to combine specific, sensitive and quantitative techniques in detecting apoptosis.展开更多
In peripheral artery disease patients,the blood supply directed to the lower limbs is reduced.This results in severe limb ischemia and thereby enhances pain sensitivity in lower limbs.The painful perception is induced...In peripheral artery disease patients,the blood supply directed to the lower limbs is reduced.This results in severe limb ischemia and thereby enhances pain sensitivity in lower limbs.The painful perception is induced and exaggerate during walking,and is relieved by rest.This symptom is termed by intermittent claudication.The limb ischemia also amplifies autonomic responses during exercise.In the process of pain and autonomic responses originating exercising muscle,a number of receptors in afferent nerves sense ischemic changes and send signals to the central nervous system leading to autonomic responses.This review integrates recent study results in terms of perspectives including how nerve growth factor affects muscle sensory nerve receptors in peripheral artery disease and thereby alters responses of sympathetic nerve activity and blood pressure to active muscle.For the sensory nerve receptors,we emphasize the role played by transient receptor potential vanilloid type 1,purinergic P2X purinoceptor 3 and acid sensing ion channel subtype 3 in amplified sympathetic nerve activity responses in peripheral artery disease.展开更多
基金Supported by the National Natural Foundation of China (No. 30570597)
文摘Objective： To investigate the expression of P2X receptors on rat intracardiac and paratracheal ganglion neurons. Methods： For preparation of intracardiac neurons, hearts were excised, the atria were separated and the medial region containing intracardiac ganglia was isolated and cut into pieces. For preparation of paratracheal neurons, the tracheas were removed and the superficial membranous layer containing paratracheal ganglia was rapidly isolated. Intracardiac and paratracheal ganglion neurons were dissociated after digestion by collagenase and trypsin. Whole-cell patch clamp recording was used to identify the pharmacological properties of P2X receptors in cultured neurons. Results：Neurons from these two ganglia responded to ATP with a rapidly activating, sustained inward current, αβ-meATP failed to evoke any re- sponses in paratracheal ganglion neurons while a few of intracardiac ganglion neurons responded to αβ- meATP with a tiny sustained inward current. ADP and UTP had no effect on intracardiac neurons. Lowering pH potentiated ATP responses in neurons from these two ganglia whereas increasing pH inhibited ATP responses. Co-application of Zn^2＋ potentiated ATP responses in intracardiac and paratracheal ganglion neurons. Conclusion： The receptor subtypes involved in intracardiac and paratracheal ganglia appear to be homomeric P2X2, while heteromeric P2X2/3 could not be completely excluded from intracardiac neurons.
文摘The aim of this study was to compare six methods of detecting apoptosis induced by extracellular adenosine triphosphate (ATP) in human leukemic lymphocytes with purinergic P2Z receptors.These methods used were electron microscopy(EM), detection of internucleosomal DNA fragmentation by agarose gel electrophoresis, autoradiographic analysis of DNA fragmentation, in situ labeling of DNA strand breaks with fluorescein dUTP and exogenous terminal deoxynucleotidyl transferase (TUNEL), quantitation of 3 ends of DNA breaks by labeling with α 32 PdCTP(TdT assay), and quantitation of apoptotic cells with fluorescein annexin V using flow cytometry(FCA).We found EM and detection of DNA ladder pattern by agarose gel electrophoresis to be specific,but lacking in sensitivity. The combination of autoradiography and gel electrophoresis gave an increase in sensitivity of at least 50 fold although, of all the methods, the TdT assay was shown to be most sensitive. The four methods for quantifying apoptosis EM, FCA, TUNEL and TdT assay proved to be reliable and gave statistically similar results on apoptotic lymphocytes. These observations indicate it is essential to combine specific, sensitive and quantitative techniques in detecting apoptosis.
基金This work was supported by the National Institutes of Health,No.NIH P01 HL134609 and R01 HL141198(to JL).
文摘In peripheral artery disease patients,the blood supply directed to the lower limbs is reduced.This results in severe limb ischemia and thereby enhances pain sensitivity in lower limbs.The painful perception is induced and exaggerate during walking,and is relieved by rest.This symptom is termed by intermittent claudication.The limb ischemia also amplifies autonomic responses during exercise.In the process of pain and autonomic responses originating exercising muscle,a number of receptors in afferent nerves sense ischemic changes and send signals to the central nervous system leading to autonomic responses.This review integrates recent study results in terms of perspectives including how nerve growth factor affects muscle sensory nerve receptors in peripheral artery disease and thereby alters responses of sympathetic nerve activity and blood pressure to active muscle.For the sensory nerve receptors,we emphasize the role played by transient receptor potential vanilloid type 1,purinergic P2X purinoceptor 3 and acid sensing ion channel subtype 3 in amplified sympathetic nerve activity responses in peripheral artery disease.
