کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
2808168 | 1157737 | 2013 | 5 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Alarin 6-25Cys antagonizes alarin-specific effects on food intake and luteinizing hormone secretion Alarin 6-25Cys antagonizes alarin-specific effects on food intake and luteinizing hormone secretion](/preview/png/2808168.png)
Previous data from our labs and from others have demonstrated that intracerebroventricular (ICV) injection of alarin has orexigenic activity and significantly increases plasma luteinizing hormone (LH) secretion in a gonadotropin-releasing hormone (GnRH) dependent manner. The purpose of the current experiments was to determine if the amino acids at the amino-terminal end of the alarin peptide are critical for alarin’s effects on reproductive and feeding systems. First, we injected male mice ICV with full-length alarin (Ala1-25) or peptide fragments missing residues at the amino-terminal end (Ala3-25 or Ala6-25Cys). Neither peptide fragment alone, significantly increased food intake in male mice compared to controls. Second, ICV injection of Ala1-25, but not Ala3-25, significantly (p < 0.01) increased GnRH-mediated LH secretion. Surprisingly, Ala6-25Cys significantly (p < 0.05) inhibited plasma LH secretion and inhibited Ala1-25 actions.In conclusion, elimination of the first five amino acids of alarin not only abolishes the biological activity of alarin, but becomes an antagonist to alarin-specific effects. Furthermore, Ala6-25Cys seems to act as a specific antagonist to putative alarin receptors and therefore may be an important tool in identifying alarin-specific receptors.
Journal: Neuropeptides - Volume 47, Issue 1, February 2013, Pages 37–41