Electrophysiological responses to bradykinin and microinjected inositol polyphosphates in neuroblastoma cells

FEBS Letters

Tertoolen, Leon G.J.¹  Moolenaar, Wouter H.¹  Irvine, Robin F.²  Tilly, Ben C.¹ 

[1] Hubrecht Laboratory, Netherlands Institute for Developmental Biology, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands;Agricultural and Food Research Council, Institute of Animal Physiology, Department of Biochemistry, Babraham, Cambridge CB2 4 AT, England

关键词: Inositol trisphosphate;    Inositol tetrakisphosphate;    Ca2+;    Membrane potential;    Bradykinin;   

DOI  :  10.1016/0014-5793(87)80089-3

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Addition of bradykinin to mouse N1E-115 neuroblastoma cells evokes a rapid but transient rise in cytoplasmic free Ca²⁺ concentration ([Ca²⁺]i). The [Ca²⁺]_i rise is accompanied by a transient membrane hyperpolarization, due to a several-fold increase in K⁺ conductance, followed by a prolonged depolarizing phase. Pre-treatment of the cells with a Ca²⁺-ionophore abolishes the hormone-induced hyperpolarization but leaves the depolarizing phase intact. The transient hyperpolarization can be mimicked by iontophoretic injection of IP₃(1,4,5) or Ca²⁺, but not by injection of IP₃(1,3,4), IP₄(1,3,4,5) or Mg²⁺ into the cells. Instead, IP₃(1,3,4) evokes a small but significant membrane depolarization in about 50% of the cells tested. Microinjected IP₄(1,3,4,5) has no detectable effect, nor has treatment of the cells with phorbol esters. These results suggest that, while IP₃(1,4,5) triggers the release of stored Ca²⁺ to hyperpolarize the membrane, IP₃(1,3,4) may initiate a membrane depolarization.

【 授权许可】

Unknown