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Fig. 20.5
Effects of acute (2 mg/kg, s.c. injection) or chronic (2 × 200 mg 21-day release s.c. pel-
lets) CORT administration on kisspeptin (
Kiss1
) mRNA expression in the medial preoptic area
(mPOA) (
a
) and arcuate nucleus (ARC) (
b
), and on
Kiss1r
mRNA expression in the mPOA (
c
) and
ARC (
d
) in ovariectomized estradiol (E
2
)-replaced rats.
Kiss1
and
Kiss1r
mRNA levels were mea-
sured in brain micropunch samples from the mPOA or ARC using real-time RT-PCR. Quantifi cation
for
Kiss1
,
Kiss1r,
and 28S rRNA was carried out on all samples and the values are expressed as a
ratio of
Kiss1
mRNA and 28S rRNA, or
Kiss1r
mRNA and 28S rRNA (mean ± SEM). *
P
< 0.05 vs.
respective controls;
n
= 6-8 per group (from Kinsey-Jones JS, Li XF, Knox AM, Wilkinson ES,
Zhu XL, Chaudhary AA, et al. Down-regulation of hypothalamic kisspeptin and its receptor,
Kiss1r, mRNA expression is associated with stress-induced suppression of luteinising hormone
secretion in the female rat. J Neuroendocrinol. 2009 Jan;21(1):20-9. Reprinted with permission
from John Wiley & Sons)
rhesus monkeys [
62
]. The inhibitory effect of insulin-induced hypoglycemia on
pulsatile secretion of LH in adult female monkey and rats is CRF-dependent [
38
,
62
],
and involves CRF-R2, but not CRF-R1, at least in the rat [
40
]. Like other stressors,
such as restraint (psychological) and LPS (immunological), hypoglycemia down-
regulates
Kiss1
mRNA expression in the ARC and
Kiss1r
mRNA expression in
the ARC and mPOA (Figs.
20.3
and
20.4
) [
35
]. However, since kisspeptin expres-
sion is sensitive to metabolic cues [
10
], overnight fasting alone was suffi cient to
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