OBJECTIVE Uridine adenosine tetraphosphate(Up4A),a dinucleotide,contains both purine and pyrimidine moieties,and exerts its vascular influence via activation of purinergic receptors.Here,we aimed to investigate the ef...OBJECTIVE Uridine adenosine tetraphosphate(Up4A),a dinucleotide,contains both purine and pyrimidine moieties,and exerts its vascular influence via activation of purinergic receptors.Here,we aimed to investigate the effects of Up4 A on angiogenesis and the putative purinergic receptors(PR)involved in this process.METHODS Tubule formation assay was performed in 3D matrix system.In this assay,human umbilical vein endothelial cells(HUVECs)were co-cultured with pericytes with various Up4 A doses(0,1,2.5,5,10 and 20μmol·L-1)in the absence and presence of P2Y6 R antagonist MRS2578(10μmol·L-1)for 5d.Expression profile of PR subtypes and angiogenic factors was assessed in HUVECs by q-PCR with and without P2Y6 R antagonist.RESULTS No difference in initial tubule formation was detected between Up4 A stimulation and control conditions at day 2.In contrast,a significant increase in vascular density in response to Up4 A was observed at day 5.Up4 A at a dose of 2.5and 5μmol·L-1 promoted total tubule length(by-1.89 fold and-2.23fold),number of tubules(by-1.71 fold and-1.89fold)as well as number of junctions(by-2.24 fold and-2.80fold),all of which were inhibited by MRS2578.Further increase in Up4 A dose to10 and 20μmol·L-1 did not induce an increase in these vascular parameters as compared to non-treated controls.Moreover,Up4 A increased mRNA level of P2YRs(P2Y2R,P2Y4 R and P2Y6R)but not P2XR(P2X4R and P2X7R)or P1R(A2AR and A2BR),while Up4 A upregulated VEGFA and ANGPT1 but not VEGFR2,ANGPT2,Tie1 and Tie2at mRNA level.Transcriptional upregulation of P2 YRs and angiogenic factors by Up4 A was inhibited by MRS2578.CONCLUSION Up4 A is functionally capable of promoting tubule formation in vitro co-culture system.This process is likely mediated by activation of pyrimidine-favored P2 YRs but not P2 XR or P1 Rs,and involves stimulation of well known angiogenic factors.展开更多
OBJECTIVE Prepulse inhibition(PPI)of the acoustic startle response provides a measure of sensorimotor gating system mecha⁃nisms,which is known to be impaired in schizo⁃phrenia patients.We assessed the effects of the 5...OBJECTIVE Prepulse inhibition(PPI)of the acoustic startle response provides a measure of sensorimotor gating system mecha⁃nisms,which is known to be impaired in schizo⁃phrenia patients.We assessed the effects of the 5-HT2A/2C receptor agonist(±)2,5-dimethoxy-4-methylamphetamine(DOM),the NMDA receptor antagonist ketamine,the dopamine receptor ago⁃nist methamphetamine(Meth)on PPI and the startle magnitude in SD rats.METHODS AND RESULTS Systemic administration of the three compounds all dose-dependently reduced PPI.However,as far as startle magnitude,only DOM at the doses of 3 mg·kg-1 reduced that,while both ketamine and Meth did not change the startle magnitudes.Furthermore,to determine whether 5-HT2A receptor mediate this effect,the non-spe⁃cific 5-HT2 receptor antagonist cyproheptadine,specific 5-HT2A receptor antagonist ketanserin and specific 5-HT2C receptor antagonist SB242084 were tested.Cyproheptadine,ketan⁃serin and SB242084 did not alter startle ampli⁃tude by themselves in SD rats and only ketanserin slightly increased PPI at higher dose(3 mg·kg-1).PPI impairment induced by DOM was restored by pretreatment of cyproheptadine(1 mg·kg-1)and ketanserin(1 mg·kg-1),while not by pretreat⁃ment of SB242084(1 mg·kg-1).Damage of PPI induced by ketamine and Meth was not reversed by cyproheptadine(1 and 5 mg·kg-1).CONCLU⁃SION The receptor mechanisms underlying the disruption of PPI caused by DOM,ketamine and Meth were different from each other,at least 5-HT2A receptor was not the junction receptor for which the three chemicals acted.展开更多
文摘OBJECTIVE Uridine adenosine tetraphosphate(Up4A),a dinucleotide,contains both purine and pyrimidine moieties,and exerts its vascular influence via activation of purinergic receptors.Here,we aimed to investigate the effects of Up4 A on angiogenesis and the putative purinergic receptors(PR)involved in this process.METHODS Tubule formation assay was performed in 3D matrix system.In this assay,human umbilical vein endothelial cells(HUVECs)were co-cultured with pericytes with various Up4 A doses(0,1,2.5,5,10 and 20μmol·L-1)in the absence and presence of P2Y6 R antagonist MRS2578(10μmol·L-1)for 5d.Expression profile of PR subtypes and angiogenic factors was assessed in HUVECs by q-PCR with and without P2Y6 R antagonist.RESULTS No difference in initial tubule formation was detected between Up4 A stimulation and control conditions at day 2.In contrast,a significant increase in vascular density in response to Up4 A was observed at day 5.Up4 A at a dose of 2.5and 5μmol·L-1 promoted total tubule length(by-1.89 fold and-2.23fold),number of tubules(by-1.71 fold and-1.89fold)as well as number of junctions(by-2.24 fold and-2.80fold),all of which were inhibited by MRS2578.Further increase in Up4 A dose to10 and 20μmol·L-1 did not induce an increase in these vascular parameters as compared to non-treated controls.Moreover,Up4 A increased mRNA level of P2YRs(P2Y2R,P2Y4 R and P2Y6R)but not P2XR(P2X4R and P2X7R)or P1R(A2AR and A2BR),while Up4 A upregulated VEGFA and ANGPT1 but not VEGFR2,ANGPT2,Tie1 and Tie2at mRNA level.Transcriptional upregulation of P2 YRs and angiogenic factors by Up4 A was inhibited by MRS2578.CONCLUSION Up4 A is functionally capable of promoting tubule formation in vitro co-culture system.This process is likely mediated by activation of pyrimidine-favored P2 YRs but not P2 XR or P1 Rs,and involves stimulation of well known angiogenic factors.
文摘OBJECTIVE Prepulse inhibition(PPI)of the acoustic startle response provides a measure of sensorimotor gating system mecha⁃nisms,which is known to be impaired in schizo⁃phrenia patients.We assessed the effects of the 5-HT2A/2C receptor agonist(±)2,5-dimethoxy-4-methylamphetamine(DOM),the NMDA receptor antagonist ketamine,the dopamine receptor ago⁃nist methamphetamine(Meth)on PPI and the startle magnitude in SD rats.METHODS AND RESULTS Systemic administration of the three compounds all dose-dependently reduced PPI.However,as far as startle magnitude,only DOM at the doses of 3 mg·kg-1 reduced that,while both ketamine and Meth did not change the startle magnitudes.Furthermore,to determine whether 5-HT2A receptor mediate this effect,the non-spe⁃cific 5-HT2 receptor antagonist cyproheptadine,specific 5-HT2A receptor antagonist ketanserin and specific 5-HT2C receptor antagonist SB242084 were tested.Cyproheptadine,ketan⁃serin and SB242084 did not alter startle ampli⁃tude by themselves in SD rats and only ketanserin slightly increased PPI at higher dose(3 mg·kg-1).PPI impairment induced by DOM was restored by pretreatment of cyproheptadine(1 mg·kg-1)and ketanserin(1 mg·kg-1),while not by pretreat⁃ment of SB242084(1 mg·kg-1).Damage of PPI induced by ketamine and Meth was not reversed by cyproheptadine(1 and 5 mg·kg-1).CONCLU⁃SION The receptor mechanisms underlying the disruption of PPI caused by DOM,ketamine and Meth were different from each other,at least 5-HT2A receptor was not the junction receptor for which the three chemicals acted.
