INVESTIGADORES
LABOMBARDA Maria Florencia
artículos
Título:
Cellular basis for progesterone neuroprotection in the injured spinal cord
Autor/es:
LABOMBARDA F; GONZALEZ S; GONZALEZ DENISELLE, C; GUENNOUN R; SCHUMACHER M; DE NICOLA A
Revista:
JOURNAL OF NEUROTRAUMA.
Referencias:
Año: 2002 vol. 19 p. 343 - 355
ISSN:
0897-7151
Resumen:
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Progesterone
(PROG) exerts beneficial and neuroprotective effects in the injured central and
peripheral nervous system. In the present work, we examine PROG effects on
three measures of neuronal function under negative regulation (choline
acetyltransferase [ChAT] and Na,K-ATPase) or stimulated (growth-associated
protein [GAP-43]) after acute spinal cord transection injury in rats. As
expected, spinal cord injury reduced ChAT immunostaining intensity of ventral
horn neurons. A 3-day course of intensive PROG treatment of transected rats
restored ChAT immunoreactivity, as assessed by frequency histograms that
recorded shifts from predominantly light neuronal staining to medium, dark or
intense staining typical of control rats. Transection also reduced the
expression of the mRNA for the a3 catalytic and b1 regulatory subunits
of neuronal Na,K-ATPase, whereas PROG treatment restored both subunit mRNA to
normal levels. Additionally, the upregulation observed for GAP-43 mRNA in
ventral horn neurons in spinal cordtransected rats, was further enhanced by
PROG administration. In no case did PROG modify ChAT immunoreactivity, Na,K-ATPase
subunit mRNA or GAP-43 mRNA in control, sham-operated rats. Further, the
PROGmediated effects on these three markers were observed in large, presumably
Lamina IX motoneurons, as well as in smaller neurons measuring approximately ,500 m2. Overall, the
stimulatory effects of PROG on ChAT appears to replenish acetylcholine, with
its stimulatory effects on Na,K-ATPase seems capable of restoring membrane
potential, ion transport and nutrient uptake. PROG effects on GAP-43 also
appear to accelerate reparative responses to injury. As the cellular basis for
PROG neuroprotection becomes better understood it may prove of therapeutic
benefit to spinal cord injury patients.