caa a22 4500 397555776 CHVBK 20180308164801.0 cr unu---uuuuu 161202e199601 xx s 000 0 eng 10.1093/oxfordjournals.jbchem.a021214 doi (NATIONALLICENCE)oxford-10.1093/oxfordjournals.jbchem.a021214 Analytical Studies of Spontaneous and Vasopressin-Induced Calcium Oscillations in Cultured Vascular Smooth Muscle Cells [Elektronische Daten] [Sheng-Nan Wu, Hsin-Su Yu, Yousuke Seyama] Spontaneous and vasopressin-induced Ca2+ oscillations in cultured vascular smooth muscle (A7r5) cells were further examined and characterized. Intracellular Ca2+ concentrations ([Ca2+]1) were measured by use of a high-performance laser cytometer. When the oscillatory patterns in [Ca2+]1 were analyzed with a power spectrum method, about 80% of cells exhibited spontaneous Ca2+ oscillations with the frequency of 0.02-0.5 Hz. Nifedipine abolished these repetitive spikes, whereas pinacidil partially attenuated their amplitude and frequency. When vasopressin (100 nM) was applied to A7r5 cells, there was an initial rise in [Ca2+]1, followed by a delayed sustained increase in [Ca2+]1,. The one-pool, nonoscil-latory model was employed to fit this biphasic change, and the difference between the observed response and the simulated response was then analyzed with a power spectral method. About 50% of cells were noted to display oscillatory patterns in [Ca2+]1, after sustained increase in [Ca2+]1,. The present study indicates that spontaneous [Ca2+ oscillations in A7r5 cells are modulated by the activity of ATP-sensitive K+ channels and are not related to pertussis toxin-sensitive GTP-binding protein(s). On the basis of the one-pool, nonoscillatory model, it is suggested that the buffering capacity of internal stores appears to be stronger in the cells with spontaneous Ca2+ oscillations than in those in a quiescent state, and the vasopressin-mediated inhibition of accumulation by internal stores was attenuated when the cells exhibited spontaneous Ca2+ oscillations. The implementation of this minimum kinetic model integrated with a power spectrum method would be an alternative to understand the oscillating behavior in [Ca2+]1,. © by the Journal of Biochemistry Regular Papers nationallicence Ca2+ oscillations nationallicence power spectrum nationallicence smooth muscle cell nationallicence vasopressin nationallicence Wu Sheng-Nan Department of Medical Education and Research, Kaohsiung-Veterans General Hospital Kaohsiung, Taiwan aut Yu Hsin-Su Department of Dermatology, Kaohsiung Medical College Kaohsiung, Taiwan aut Seyama Yousuke Department of Physiological Chemistry and Nutrition, Faculty of Medicine The University of Tokyo, Bunkyo-ku, Tokyo 113 aut The Journal of Biochemistry Oxford University Press 119/1(1996-01), 42-48 0021-924X 119:1<42 1996 119 jbchem https://doi.org/10.1093/oxfordjournals.jbchem.a021214 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1093/oxfordjournals.jbchem.a021214 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Wu Sheng-Nan Department of Medical Education and Research, Kaohsiung-Veterans General Hospital Kaohsiung, Taiwan aut NATIONALLICENCE 700 1- Yu Hsin-Su Department of Dermatology, Kaohsiung Medical College Kaohsiung, Taiwan aut NATIONALLICENCE 700 1- Seyama Yousuke Department of Physiological Chemistry and Nutrition, Faculty of Medicine The University of Tokyo, Bunkyo-ku, Tokyo 113 aut NATIONALLICENCE 773 0- The Journal of Biochemistry Oxford University Press 119/1(1996-01), 42-48 0021-924X 119:1<42 1996 119 jbchem Metadata rights reserved CC BY-NC-4.0 http://creativecommons.org/licenses/by-nc/4.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-oxford