Cyclic Adenosine Monophosphate Production by Embryonic Chick Cells

Abstract
Cells dissociated from 1-day-old chick embryos produce a pulse of cyclic adenosine monophosphate (cyclic AMP) when stimulated with cyclic AMP. There is a stimulus threshold concentration of about 10(-8) molar cyclic AMP and an upper limit, above which the response is suppressed, of about 6 X 10(-6) molar. The response occurs within 5 seconds of stimulation and corresponds to an average pulse size in the range of 10(7) molecules per cell.