Functional expression of cholecystokinin-A receptor on ventromedial hypothalamic neurons in the immature rat brain.
Cholecystokinin-8 (CCK-8) dose-dependently increased the cytosolic Ca2+ concentration ([Ca]i) in ventromedial hypothalamic neurons acutely dissociated from the immature rat brain. The CCK-8 response was mimicked by caerulein, but not by CCK(B) agonists, and was often inhibited by CCK(A) receptor antagonists, but rarely by CCK(B) receptor antagonists. The response was dependent on external Ca2+ and Na+, and was inhibited by voltage-dependent Ca2+ channel blockers. The results suggest that CCK-8-induced depolarization via CCK(A) receptors increased Ca2+ influx through a voltage-dependent Ca2+ channel, which in turn increased [Ca]i.
Sorimachi
M
M
Department of Physiology, Faculty of Medicine, Kagoshima University, Japan. ciliary@m.kufm.kagoshima-u.ac.jp
Yamagami
K
K
Uramura
K
K
D000367:Age Factors; D000818:Animals; D001069:Appetite Regulation / Q000187:drug effects / Q000502:physiology*; D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels / Q000187:drug effects / Q000378:metabolism*; D020013:Calcium Signaling / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured / Q000187:drug effects / Q000378:metabolism; D003600:Cytosol / Q000187:drug effects / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D043886:Receptor, Cholecystokinin A; D043887:Receptor, Cholecystokinin B; D011949:Receptors, Cholecystokinin / Q000819:agonists / Q000037:antagonists & inhibitors / Q000378:metabolism*; D012844:Sincalide / Q000819:agonists* / Q000037:antagonists & inhibitors* / Q000378:metabolism; D014697:Ventromedial Hypothalamic Nucleus / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*
D015220:Calcium Channels; D043886:Receptor, Cholecystokinin A; D043887:Receptor, Cholecystokinin B; D011949:Receptors, Cholecystokinin; D012844:Sincalide; D002118:Calcium