Journal of Neuroscience, Vol 1, 1085-1095, Copyright © 1981 by Society for Neuroscience
The action of nerve growth factor and dibutyryl adenosine cyclic 3':5'- monophosphate on rat pheochromocytoma reveals distinct stages in the mechanisms underlying neurite outgrowth
PW Gunning, PC Letourneau, GE Landreth and EM Shooter
The clonal rat pheochromocytoma, PC12, responds to nerve growth factor
(NGF) and dibutyryl adenosine cyclic 3':5'monophosphate (dbc AMP) by the
elevation of cellular protein and RNA levels in all three parameters that
are additive or greater than the sum of those caused by either agent alone,
indicating that the mechanisms by which the two agents act to produce these
changes are distinct. The concentration of dbcAMP required for half-maximal
stimulation of these changes is also different for each, while NGF is
active in all instances at 10(-11) M. PC12 cells initially generate
neurites slowly in response to NGF and, at the same time, develop the
capacity to regenerate neurites rapidly, a process termed priming. The
cells, however, are not primed by dbcAMP nor does it influence the ability
of NGF to prime them. Time lapse cinematography demonstrates that both NGF
and dbcAMP each have unique effects on cellular morphology. The latter
produces' rapid, unstable neurite initiation but does not promote sustained
neurite extension. In contrast, NGF has immediate effects at the cell
surface with no neurite initiation but later produces sustained neurite
outgrowth. Utilizing dbcAMP, it is possible to dissect four morphological
response of PC12 cells to NGF. Three of these may be mechanistically
closely tied to occupancy of the NGF plasma membrane receptor.