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Abstract
Immunocytochemical β-endorphin (β-EP) staining and ultrastructual observations in
the hypothalamus were compared in normal mature female rats, ovariectomized rats,
and aged female rats. The effects of oestradiol benzoate (EB) on the hypothalamus
were studied. The female Wistar rats were divided into seven groups, as follows: 40-day-old
rats (Mature), 54-day-old rats ovariectomized at 40 days (Ovx), rats ovariectomized
at 40 days and injected with 0.1 mg EB daily for 7 days (Ovx + e), rats ovariectomized
and injected with one dose of 1 mg EB (Ovx + E), 500-day-old (Old), old rats injected
with 0.1 mg EB daily for 7 days (Old + e), and old rats injected with 1 mg EB (Old
+ E). In the Ovx and Old groups, β-EP-positive cells in the arucuate nucleus were
rarely seen, as compared with the Mature group. The staining of β-EP-positive cells
in Ovx + e was slightly recovered and that in Ovx + E was almost completely recovered.
However, no recovery of β-EP-positive cells was seen in the Old + e or Old + E groups.
The number of nerve fibers in the median eminence were reduced in both the Ovx and
Old groups, as compared with the Mature group. There was no relationship between changes
in these numbers and oestrogen replacement in the Old group, but in the Ovx group
oestrogen replacement brought about recovery of these numbers. The number of glial
cells increased after oestrogen replacement in both the Ovx and Old groups. The frequency
of giant mitochondria in the neurons in the arcuate nucleus decreased after oestrogen
replacement in the Old group.
Keywords
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Article info
Publication history
Accepted:
November 20,
1992
Received in revised form:
July 8,
1992
Received:
March 12,
1992
Identification
Copyright
© 1993 Published by Elsevier Inc.
