Objective. To investigate the characteristics of urotensin II (U II) receptor in the rat airway smooth muscle and the effect and signal transduction pathway of U II on the proliferation of airway smooth muscle cells. ...Objective. To investigate the characteristics of urotensin II (U II) receptor in the rat airway smooth muscle and the effect and signal transduction pathway of U II on the proliferation of airway smooth muscle cells. Methods. Using 125I UII binding assay to measure the Bmax and Kd of U II receptor. Using the 3H TdR incorporation to determine the effect of U II on the proliferation of airway smooth muscle cells and its signal transduction pathway. Using Fura 2/AM to measure the effect of U II on the cytosolic free calcium concentration. Results. 1. 125I UII binding increased with the time and reached saturation at 45min. The Bmax was (11.36±0.37)fmol/mg pr and Kd was (4.46±0.61)nmol/L. 2. U II increased 3H TdR incorporation of the airway smooth muscle cells in a dose dependent manner. 3. H7, PD98059 and nicardipine, inhibitors of PKC, MAPK, calcium channel, respectively, significantly inhibited U II stimulated 3H TdR incorporation of airway smooth muscle cells. W7, inhibitor of CaM PK, had no effect. 4. Cyclosporin A, inhibitor of CaN, inhibited 3H TdR incorporation of the airway smooth muscle cells induced by U II in a dose dependent manner. 5. U II promoted cytosolic free calcium concentration increase by 18%. Conclusions. 1. There was U II receptor in the rat airway smooth muscle. 2. The effect of U II stimulated 3H TdR incorporation of airway smooth muscle cells was mediated by such signal transduction pathway as Ca2+, PKC, MAPK and CaN, etc.展开更多
Objective: To design an extravascular trestle model coated phosphorus-32, an isotope radiating beta rays, and investigate its effects on intimal hyperplasia of autologous vein grafts. Methods: ETA cDNA was used as a g...Objective: To design an extravascular trestle model coated phosphorus-32, an isotope radiating beta rays, and investigate its effects on intimal hyperplasia of autologous vein grafts. Methods: ETA cDNA was used as a gene probe specific to vascular SMCs on the basis of in situ hybridization. The femoral veins were transplanted reversely into colateral femoral arteries in rabbits, and the animals were divided into control, chemical agents and phosphorus-32 groups. The morphometry was applied to calculate the ETA cDNA expression and intimal thickness. Spearman correlation method was utilized to investigate their relationship. Results: Intimal thickness in grafts of phosphorus-32 group was markedly reduced. Additionally, intimal ETA gene expression was also decreased in beta rays group. The values increased at a slower rate significantly different from that of control and aspirin groups (P<0.01). The correlation of ETA cDNA expression and intimal thickness exhibited a strongly positive relation. Conclusion: Beta rays in extravascular model could remarkably inhibit intimal thickening and SMC proliferation. The correlation is an indirect evidence indicating that intimal hyperplasia composed of SMCs proliferation. It suggests that ETA cDNA expression could be a quantitative estimation of vascular SMC because of its specifics.展开更多
文摘Objective. To investigate the characteristics of urotensin II (U II) receptor in the rat airway smooth muscle and the effect and signal transduction pathway of U II on the proliferation of airway smooth muscle cells. Methods. Using 125I UII binding assay to measure the Bmax and Kd of U II receptor. Using the 3H TdR incorporation to determine the effect of U II on the proliferation of airway smooth muscle cells and its signal transduction pathway. Using Fura 2/AM to measure the effect of U II on the cytosolic free calcium concentration. Results. 1. 125I UII binding increased with the time and reached saturation at 45min. The Bmax was (11.36±0.37)fmol/mg pr and Kd was (4.46±0.61)nmol/L. 2. U II increased 3H TdR incorporation of the airway smooth muscle cells in a dose dependent manner. 3. H7, PD98059 and nicardipine, inhibitors of PKC, MAPK, calcium channel, respectively, significantly inhibited U II stimulated 3H TdR incorporation of airway smooth muscle cells. W7, inhibitor of CaM PK, had no effect. 4. Cyclosporin A, inhibitor of CaN, inhibited 3H TdR incorporation of the airway smooth muscle cells induced by U II in a dose dependent manner. 5. U II promoted cytosolic free calcium concentration increase by 18%. Conclusions. 1. There was U II receptor in the rat airway smooth muscle. 2. The effect of U II stimulated 3H TdR incorporation of airway smooth muscle cells was mediated by such signal transduction pathway as Ca2+, PKC, MAPK and CaN, etc.
文摘Objective: To design an extravascular trestle model coated phosphorus-32, an isotope radiating beta rays, and investigate its effects on intimal hyperplasia of autologous vein grafts. Methods: ETA cDNA was used as a gene probe specific to vascular SMCs on the basis of in situ hybridization. The femoral veins were transplanted reversely into colateral femoral arteries in rabbits, and the animals were divided into control, chemical agents and phosphorus-32 groups. The morphometry was applied to calculate the ETA cDNA expression and intimal thickness. Spearman correlation method was utilized to investigate their relationship. Results: Intimal thickness in grafts of phosphorus-32 group was markedly reduced. Additionally, intimal ETA gene expression was also decreased in beta rays group. The values increased at a slower rate significantly different from that of control and aspirin groups (P<0.01). The correlation of ETA cDNA expression and intimal thickness exhibited a strongly positive relation. Conclusion: Beta rays in extravascular model could remarkably inhibit intimal thickening and SMC proliferation. The correlation is an indirect evidence indicating that intimal hyperplasia composed of SMCs proliferation. It suggests that ETA cDNA expression could be a quantitative estimation of vascular SMC because of its specifics.
