Bradykinin causes a transient rise of intracellular Ca2+-activity in cultured neural cells.
The concentration of intracellular free calcium ions was measured by spectrofluorometry in suspensions of quin2 loaded neural cell lines: neuroblastoma X glioma hybrid cells (clones 108CC15 and 108CC25) and polyploid rat glioma cells (clone C6-4-2). In these cells, bradykinin elicits a transient increase of the cytosolic Ca2+-activity in a dose-dependent manner (half-maximal effect at about 10 nM). The effect requires the presence of extracellular Ca2+. The time to peak is at most 10 s, the decay to the original level lasts 1 min and is followed by a period of 1-4 min during which Ca2+ activity is slightly below control value. Lys-bradykinin and Met-Lys-bradykinin evoke similar effects as bradykinin, but at concentrations 10 times lower. The cells desensitize upon repeated addition of bradykinin. Under the same conditions des-Arg1-bradykinin, des-Arg9-bradykinin, angiotensin II, substance P, apamin and histamine exerted no influence on the concentrations of free Ca2+. Similar to their effect in neural cell lines, bradykinin and Lys-bradykinin induce in primary astroglia-rich cultures from rat brain an increase in the concentration of cytosolic Ca2+ with the peak reached within 30 s and the decay to the original level lasting approximately 4 min. The significance of this effect of bradykinin on the cytosolic Ca2+-activity is discussed in relation to previous findings that bradykinin in the same cell lines induces a hyperpolarization, a rise of the cyclic GMP level and a breakdown of phosphoinositides.
D000634:Aminoquinolines; D000818:Animals; D001920:Bradykinin / Q000494:pharmacology*; D001921:Brain / Q000166:cytology / Q000378:metabolism; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D005453:Fluorescence; D005910:Glioma / Q000473:pathology; D006822:Hybrid Cells / Q000473:pathology; D007425:Intracellular Membranes / Q000378:metabolism*; D051379:Mice; D009447:Neuroblastoma / Q000473:pathology; D009474:Neurons / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D010042:Ouabain / Q000494:pharmacology; D051381:Rats
D000634:Aminoquinolines; D010042:Ouabain; C035738:Quin2-acetoxymethyl ester; D001920:Bradykinin; D002118:Calcium