S. Vanhatalo et al., COLCHICINE DIFFERENTIALLY INDUCES THE EXPRESSIONS OF NITRIC-OXIDE SYNTHASES IN CENTRAL AND PERIPHERAL CATECHOLAMINERGIC NEURONS, Experimental neurology, 150(1), 1998, pp. 107-114
This study was aimed at elucidating differences in nerve injury induce
d expression of nitric oxide synthases (NOS) between the peripheral an
d central catecholaminergic neurons. Colchicine was used to disrupt ch
emically the neuronal cytoskeletal integrity. A marked increase in the
expression of neuronal NOS-IR and NADPH-diaphorase activity, a marker
of neuronal NOS (nNOS), was seen in distinct populations of postgangl
ionic sympathetic neurons of the superior cervical ganglion after intr
aganglionic colchicine injection. Similarly, immunoreactivity for the
inducible form of NOS (iNOS) was induced in some sympathetic neuron so
mata. However, this immunoreactivity did not coincide with nNOS-IR, In
contrast to the sympathetic neurons, hypothalamic arcuate and periven
tricular dopaminergic neurons did not show NOS-IR or NADPH-DA either i
n intact animals or in animals treated with an intracerebroventricular
injection of colchicine. Immunoreactivity for the inducible form of N
OS revealed no neuronal staining in the hypothalamic neurons in either
group, while a large number of glia-resembling cells around the third
ventricle showed slight expression of iNOS-IR. The present results sh
ow that expression of both neuronal and inducible forms of NOS may be
induced by colchicine in some catecholaminergic neurons. It is suggest
ed that these inductions are specific to certain catecholaminergic neu
ronal systems, like the sympathetic neurons, rather than a general pro
perty of catecholaminergic neurons. (C) 1998 Academic Press.