ORIGINAL PAPER
The effect of intracerebroventricular infusions of ghrelin
on the secretory activity of the GnRH/LH system
in peripubertal ewes
1 |
The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, 05-110 Jabłonna, Poland |
J. Anim. Feed Sci. 2014;23(4):299–308
Publication date: 2014-11-27
KEYWORDS
ABSTRACT
Ghrelin is a 28-amino acid orexigenic peptide, synthesized mainly
by cells located in the stomach mucosa, that can be also engaged in modulation
of reproductive functions. The aim of this study was to investigate the effect
of intracerebroventricular (icv) infusion of ghrelin on the secretory activity
of the gonadotropin hormone releasing hormone/luteinizing hormone (GnRH/
LH) system in peripubertal ewes. The animals were randomly divided into three
groups: 1. standard fed, 2. starved for 72 h, and 3. standard fed + icv infused
with ghrelin. Infusions were performed during three consecutive days; blood
samples were collected on day 0 and day 3. Ghrelin infusions and short-term
starvation increased the accumulation of immunoreactive (ir) GnRH material in
the median eminence (P < 0.001) and ir LH material in the secretory granules
of pituitary cells (P < 0.001) in the fasted and ghrelin-infused groups. The short
starvation resulted in a decrease of mean LH plasma concentrations (P < 0.05)
between days 0 and 3 of infusion, which was related to a lower pulse amplitude.
After the icv ghrelin infusion, significant (P < 0.05) changes in LH pulse amplitude
and frequency, but not in LH concentrations were observed. The obtained
results revealed that in peripubertal ewes, exogenous ghrelin administration
affects the GnRH/LH axis mainly at the level of neurohormone/protein accumulation
and LH pulsatility modifications. Ghrelin action at the hypothalamuspituitary
axis is likely involved in the endocrine network that integrates energy
balance and fertility in immature sheep.
CORRESPONDING AUTHOR
A. Wójcik-Gładysz
The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, 05-110 Jabłonna, Poland
CITATIONS (4):
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Effects of intracerebroventricular infusions of ghrelin on secretion of follicle-stimulating hormone in peripubertal female sheep Anna W�jcik-Gładysz, Marta Wańkowska, Alina Gajewska, Tomasz Misztal, Marlena Zielińska-G�rska, Michał Szlis, Jolanta Polkowska Reproduction, Fertility and Development
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Obestatin stimulates the somatotrophic axis activity in sheep Anna Wójcik-Gładysz, Michał Szlis, Anna Misztal, Bartosz Jarosław Przybył, Jolanta Polkowska Brain Research
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3. |
Does obestatin modulate the hypothalamic appetite-regulating network in peripubertal sheep? M. Szlis, J. Polkowska, E. Skrzeczyńska, B. J. Przybył, A. Wójcik-Gładysz Journal of Animal Physiology and Animal Nutrition
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4. |
Central obestatin administration affect the LH and FSH secretory activity in peripubertal sheep. Michał Szlis, Anna Wójcik-Gładysz, Bartosz Przybył Theriogenology
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