Relationship between ghrelin and estrogen in the ovary of pregnant sheep

Document Type: Reproduction

Authors

1 Department of Clinical Sciences, School of Veterinary Medicine, Lorestan University, P. O. Box: 465, Khorramabad, Iran

2 Division of Biochemistry, School of Veterinary Medicine, Lorestan University, P. O. Box: 465, Khorram Abad, Iran

Abstract

Background:Ghrelin, an endogenous ligand for the growth
secretagogue receptor is predominantly produced in the stomach and an
expression of ghrelin has recently been identified in placenta and ovary.
OBJECTIVES: Therefore, we decited to measure ovarian ghrelin as quantitative and
evaluate the correlation between ghrelin and estrogen during second half of
ovine pregnancy.
METHODS: The ovarian samples were collected from 40
pregnant sheep in 3, 3.5, 4, 4.5 and 5 months of pregnancy in a local abattoir.
Follicles and active corpora lutea (CL) were dissected from surrounding
tissues, separately. The samples were homogenized with phosphate buffer (0.1 M,
pH=7.4) on liquid nitrogen to provide fluid samples. Ghrelin and estrogen
concentrations were measured by ELISA method and expressed as milligram (mg)
and picogram (pg) per mg of tissue protein, respectively.
RESULTS:
There was a linear correlation between ghrelin and estrogen in ovarian follicles
(r=0.97 and p=0.004), but not in CL. Follicular ghrelin significantly increased
in 4, 4.5 and 5 months (p<0.001) but CL ghrelin significantly decreased in
the 4.5 month of ovine pregnancy (p<0.01). Estrogen concentration was also
significantly higher in 4-5 months of pregnancy in ovarian follicles
(p<0.001) but potent CL indicated higher estrogen level only in the 5th
month of pregnancy (p<0.001).
CONCLUSIONS:
These results emphasize the role of ghrelin in
the reproductive system and open a new window to future studies

Keywords


Article Title [Persian]

رابطه بین گرلین و استروژن در تخمدان گوسفندان آبستن

Authors [Persian]

  • علی سوخته زاری 1
  • مسعود علیرضایی 2
1 گروه علوم درمانگاهی دانشکده دامپزشکی دانشگاه لرستان، صندوق پستی 465، خرم آباد، ایران
2 بخش بیوشیمی دانشکده دامپزشکی دانشگاه لرستان، صندوق پستی 465، خرم آباد، ایران
Abstract [Persian]

زمینه مطالعه: گرلین، بعنوان یک لیگاند داخلی برای گیرنده ترشحی رشد بطور غالب در معده تولید می‌گردد و اخیراً بیان گرلین در جفت و تخمدان گزارش شده است. هدف: بنابراین ما تصمیم گرفتیم که گرلین تخمدانی را بصورت کمی ارزیابی و رابطه گرلین و استروژن را در طول نیمه دوم آبستنی در گوسفند بررسی کنیم. روش کار: نمونه‌های تخمدان از 40 میش آبستن در 3، 5/3، 4، 5/4 و 5 ماهگی از آبستنی در یک کشتارگاه محلی جمع آوری شدند. فولیکول‌ها و جسم زرد فعال از بافت‌های اطراف بصورت جداگانه تهیه گردیدند. نمونه ها با استفاده از بافر فسفات (یک دهم مولار با 7.40= pH)  بر روی ازت مایع هموژنیزه شدند تا نمونه‌های مایع بدست آید. غلظت گرلین و استروژن بوسیله روش الیزا اندازه‌گیری شد و بترتیب بصورت میلی گرم و پیکوگرم در میلی گرم از پروتئین بافت برای گرلین و استروژن بیان گردید. نتایج: یک رابطه خطی بین گرلین و استروژن در فولیکول‌های تخمدان وجود داشت ( 0.97=r,0.004=p) اما در جسم زرد این رابطه نبود. گرلین فولیکول‌ها بطور معنی‌داری در 4، 5/4 و 5 ماهگی افزایش یافت (0.001>p) ولی گرلین جسم زرد بطور معنی‌داری در 5/4 ماهگی از آبستنی گوسفند کاهش یافت (0.01>p). در فولیکول‌های تخمدان همچنین غلظت استروژن در 5-4 ماهگی آبستنی بالا بود (0.001>p) اما جسم زرد فعال فقط در 5 ماهگی غلظت استروژن بالاتری نشان داد (0.001>p). نتیجه گیری نهایی: این نتایج نقش گرلین را در سیستم تولید مثل برجسته می‌کند و دریچه جدیدی رو به مطالعات آینده باز می‌کند.

Keywords [Persian]

  • جسم زرد
  • استروژن
  • فولیکول
  • گرلین
  • گوسفند
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