Effects of intracerebroventricular infusions of ghrelin on secretion of follicle-stimulating hormone in peripubertal female sheep.
Reproduction depends on mechanisms responsible for the regulation of energy homeostasis and puberty is a developmental period when reproductive and somatic maturity are achieved. Ghrelin affects the activity of the hypothalamo-pituitary-gonadal axis under conditions of energy insufficiency. An in vivo model based on intracerebroventricular (i.c.v.) infusions was used to determine whether centrally administered acyl ghrelin affects transcriptional and translational activity of FSH in peripubertal lambs and whether ghrelin administration mimics the effects of short-term fasting. Standard-fed lambs received either Ringer-Lock (R-L) solution (120µL h-1) or ghrelin (120µL h-1, 100µg day-1). Animals experiencing a short-term (72h) fast were treated only with R-L solution. In each experimental group, i.c.v. infusions occurred for 3 consecutive days. Immunohistochemistry, in situ hybridisation and real-time reverse transcription quantitative polymerase chain reaction analyses revealed that short-term fasting, as well as exogenous acyl ghrelin administration to standard-fed peripubertal lambs, augmented FSHβ mRNA expression and immunoreactive FSH accumulation. In addition to the effects of ghrelin on FSH synthesis in standard-fed animals, effects on gonadotrophin release were also observed. Acyl ghrelin increased the pulse amplitude for gonadotrophin release, which resulted in an elevation in mean serum FSH concentrations. In conclusion, the present data suggest that ghrelin participates in an endocrine network that modulates gonadotrophic activity in peripubertal female sheep.
Polish Academy of Sciences, The Kielanowski Institute of Animal Physiology and Nutrition, 3 Instytucka st, 05-110 Jab?onna, Poland.
Anna
A
Wójcik-Gładysz
Polish Academy of Sciences, The Kielanowski Institute of Animal Physiology and Nutrition, 3 Instytucka st, 05-110 Jab?onna, Poland.
Marta
M
Wańkowska
Polish Academy of Sciences, The Kielanowski Institute of Animal Physiology and Nutrition, 3 Instytucka st, 05-110 Jab?onna, Poland.
Alina
A
Gajewska
Polish Academy of Sciences, The Kielanowski Institute of Animal Physiology and Nutrition, 3 Instytucka st, 05-110 Jab?onna, Poland.
Tomasz
T
Misztal
Polish Academy of Sciences, The Kielanowski Institute of Animal Physiology and Nutrition, 3 Instytucka st, 05-110 Jab?onna, Poland.
Marlena
M
Zielińska-Górska
Polish Academy of Sciences, The Kielanowski Institute of Animal Physiology and Nutrition, 3 Instytucka st, 05-110 Jab?onna, Poland.
Michał
M
Szlis
Polish Academy of Sciences, The Kielanowski Institute of Animal Physiology and Nutrition, 3 Instytucka st, 05-110 Jab?onna, Poland.
Jolanta
J
Polkowska
D000818:Animals; D005215:Fasting; D005260:Female; D005640:Follicle Stimulating Hormone / Q000378:metabolism*; D054439:Ghrelin / Q000494:pharmacology*; D017403:In Situ Hybridization; D057967:Infusions, Intraventricular; D012756:Sheep
D054439:Ghrelin; D005640:Follicle Stimulating Hormone