The hepatocyte calcium oscillator.
Hepatocytes stimulated with calcium-mobilising agonists generate free Ca transients whose frequency is modulated by hormone concentration. Importantly, the time-course of individual free Ca transients is independent of agonist dose but does change with agonist species. A receptor-controlled model in which protein kinase C provides negative feedback directed against the different receptors, or receptor-specific G proteins, has been proposed in order to explain the agonist-specificity of the falling phase of the free Ca spikes. Here we show further evidence, from mixing of hormones and from the effects of elevated cAMP, of receptor-specific information within the spikes.
Cobbold
P H
PH
Department of Human Anatomy & Cell Biology, University of Liverpool, UK.
Sanchez-Bueno
A
A
Dixon
C J
CJ
D000818:Animals; D001692:Biological Transport / Q000502:physiology; D002118:Calcium / Q000502:physiology*; D002478:Cells, Cultured; D008099:Liver / Q000378:metabolism*; D008954:Models, Biological; D010507:Periodicity; D015398:Signal Transduction / Q000502:physiology*
D002118:Calcium