We immunohistochemically investigated the GR expression in the brain of aged-rats by means of. In comparison with young adult rats
the reduction of intensity for GR-immunoreactivity was observed in the cerebral cortex
hippocampus and amygdala
which were well associated to the limbic system
in the aged-rats
although the circulating cortiosteroids have been indicated to show an increase with aging.The ultra structural changes on the neurons with aging
especially using a high voltage electron microscopy (HVEM) was also observed. HVEM could reveal the significant reduction of the number of spines in dendrites of CA1 pyramidal neurons and cortical neurons
and the morphological changes of these spines. On the other hand
we immunohistochemically investigated the change of several neurotransmitter relevant enzymes
such as ChAT
GAD
and TH. In the aged rats
the reduction of immunoreactivity for ChAT
as well as GAD were observed in comparison with those in the young rats. On the other hand
the intensity of TH immunoreactivity did not show any significant changes in aged rats
although the number of TH-immunoreactive cell bodies and fibers seemed to reduce.Moreover
we studied about the expression of annexin-1 in the folliculo-stellate cells in the anterior pituitary under different corticosteroid conditions. After adrenalectomy
LC1 immunoreactivity was almost disappeared
while the immunoreactivity was recovered by corticosterone replacement. The expression of GR immunoreactivity in the nucleus of FS cells also showed a similar pattern to annexin-1 associated with the corticosteroids conditions
however S100 (a marker for FS cells) immunoreactivity was not changed whatever corticosteroids conditions.These results suggest that glucocorticoids regulate the LC1 expression and promote the translocation of annexin-1 from intracellular to pericellular sites in the FS cells of rat anterior pituitary gland to interact with neighboring endocrine cells as a paracrine action. The change of annexin-1 expression in the aged rat is now going to investigate.
