INVESTIGADORES
LUX Victoria Adela R.
artículos
Título:
Gonadal steroids modulated hypocretin/orexin type-1 receptor expression in a brain
Autor/es:
PATRICIA SILVEYRA; NATALIA I. CATALDI; VICTORIA LUX-LANTOS; CARLOS LIBERTUN
Revista:
REGULATORY PEPTIDES
Editorial:
Elsevier
Referencias:
Año: 2009 vol. 158 p. 21 - 26
ISSN:
0167-0115
Resumen:
Orexins A and B (hypocretins A and B) are regulatory peptides that control a variety of neuroendocrine and
autonomic functions including feeding and sleep-wakefulness. Previously, we described a clear relationship
between the hormonal milieu of the estrous cycle and the mRNA expression of the components of the
orexinergic system, in the hypothalamus, pituitary and ovary. Here, we investigate whether steroid
hormones are involved in the modulation of the hypocretin/orexin type-1 receptor expression at the protein
level, and its time of the day dependence, in hypothalamus and pituitary of castrated male and female rats
and castrated receiving hormone replacement.
Orchidectomy decreased the hypocretin/orexin type-1 receptor expression in anterior hypothalamus, but
not in mediobasal hypothalamus or cortex; in pituitary this treatment resulted in an increase. Testosterone
and dihydrotestosterone were able to restore receptor expression and gonadotropins.
In females, pituitary and ovarian hormones increased during proestrous afternoon. Hypocretin/orexin type-1
receptor expression was higher at 19:00 of proestrus in hypothalamus and pituitary. Ovariectomized treated
with estradiol or oil and sacrificed at 11:00 h showed the receptor expression similar to 11:00 h of proestrus
in hypothalamus and pituitary. At 19:00 h, low expression persisted in these areas in oil-treated
ovariectomized rats; in contrast, estradiol replacement increased the expression to high levels of normal
cycling rats at 19:00 h.
Sexual steroids modulate the orexinergic system and the anatomical regions, hormones and times of the day
all have to be considered when the roles of orexins, and probably other peptides, are under consideration.
in hypothalamus and pituitary. At 19:00 h, low expression persisted in these areas in oil-treated
ovariectomized rats; in contrast, estradiol replacement increased the expression to high levels of normal
cycling rats at 19:00 h.
Sexual steroids modulate the orexinergic system and the anatomical regions, hormones and times of the day
all have to be considered when the roles of orexins, and probably other peptides, are under consideration.
ficed at 11:00 h showed the receptor expression similar to 11:00 h of proestrus
in hypothalamus and pituitary. At 19:00 h, low expression persisted in these areas in oil-treated
ovariectomized rats; in contrast, estradiol replacement increased the expression to high levels of normal
cycling rats at 19:00 h.
Sexual steroids modulate the orexinergic system and the anatomical regions, hormones and times of the day
all have to be considered when the roles of orexins, and probably other peptides, are under consideration.