caa a22 4500 469079223 CHVBK 20180323132944.0 cr unu---uuuuu 170328e19920301xx s 000 0 eng 10.1007/BF00168695 doi (NATIONALLICENCE)springer-10.1007/BF00168695 Different and common intracellular calcium-stores mobilized by noradrenaline and caffeine in vascular smooth muscle [Elektronische Daten] [M. Noguera, M. D'Ocon] Summary: Noradrenaline (NA) 1 μM and caffeine (CAF) 10 mM induce a contractile response in isolated rat aorta maintained at 37°C either in the presence or absence of extracellular calcium. In Ca-free media the contractile response was reduced and contractile activity of CAF only occurred at 25°C. NA induced a biphasic response in Ca-free medium, with a fast phasic contraction followed by a smaller more sustained contraction. The response induced by CAF consisted of a fast transient contraction which returned to a level below the resting tone. After washing, further addition of NA or CAF evoked no increase in smooth muscle tension. The influence of Mg-depletion in the extracellular medium on the contractile responses induced by NA and CAF in Ca-free medium was determined: similar response to NA or CAF in media with or without Mg after 2 min loading were observed, but after 15 min loading in Mg, Ca-free solution, the responses to NA or CAF were significantly higher than after incubation in Ca-free medium containing Mg. Differences were observed when contractile response to NA was elicited after the refilling process by loading the aortic strip in Ca-containing Mg-free solution. In this case, instead of recovering the magnitude of contraction there was a significant decrease. The existence of two independent intracellular Ca-pools releasable by NA, one of them also sensitive to CAF, is postulated. The refill of the Ca-store specific to NA is dependent on the presence of Mg in the extracellular medium. In contrast, the refill of the common Ca-pool releasable by NA and CAF is independent of the extracellular Mg, but its spontaneous emptying is temperature-, and Mg-dependent. This suggests the intermediacy of an enzymatic process to extrude the Ca-content of this store to the extracellular space. Springer-Verlag, 1992 Intracellular Ca-stores nationallicence Caffeine nationallicence Noradrenaline nationallicence Rat-aorta nationallicence Mg nationallicence Noguera M. Laboratorio de Farmacognosia y Farmacodinamia, Departamento de Farmacologia, Facultad de Farmacia, Universidad de Valencia, Avda. Blasco Ibáñez, 13, E-46010, Valencia, Spain aut D'Ocon M. Laboratorio de Farmacognosia y Farmacodinamia, Departamento de Farmacologia, Facultad de Farmacia, Universidad de Valencia, Avda. Blasco Ibáñez, 13, E-46010, Valencia, Spain aut Naunyn-Schmiedeberg's Archives of Pharmacology Springer-Verlag 345/3(1992-03-01), 333-341 0028-1298 345:3<333 1992 345 210 https://doi.org/10.1007/BF00168695 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00168695 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Noguera M. Laboratorio de Farmacognosia y Farmacodinamia, Departamento de Farmacologia, Facultad de Farmacia, Universidad de Valencia, Avda. Blasco Ibáñez, 13, E-46010, Valencia, Spain aut NATIONALLICENCE 700 1- D'Ocon M. Laboratorio de Farmacognosia y Farmacodinamia, Departamento de Farmacologia, Facultad de Farmacia, Universidad de Valencia, Avda. Blasco Ibáñez, 13, E-46010, Valencia, Spain aut NATIONALLICENCE 773 0- Naunyn-Schmiedeberg's Archives of Pharmacology Springer-Verlag 345/3(1992-03-01), 333-341 0028-1298 345:3<333 1992 345 210 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer