کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9894479 | 1542460 | 2005 | 5 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Effects of ghrelin on growth hormone secretion in vivo in ruminants
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موضوعات مرتبط
علوم زیستی و بیوفناوری
بیوشیمی، ژنتیک و زیست شناسی مولکولی
زیست شیمی
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چکیده انگلیسی
Ghrelin, a novel endogenous growth hormone (GH) secretagogue, has been shown to exert very potent and specific GH-releasing activity in rats and humans. However, little is known about its GH-releasing activity and endocrine effects in domestic animals. To clarify the effect of ghrelin on GH secretion in vivo in ruminants, plasma GH responses to intra-arterial and intra-hypothalamic injections of rat ghrelin (rGhrelin) were examined in goats and cattle. The intra-arterial injection of 1 μg/kg BW of rGhrelin in ovariectomized goats failed to stimulate GH release, however, a dosage of 3 μg/kg BW significantly increased plasma GH concentrations (P<0.05). GH levels peaked at 15 min after the injection, then decreased to basal concentrations within 1 h after the injection. However, the secretory response to 3 μg/kg BW of rGhrelin was weaker than that of growth hormone-releasing hormone (GHRH) (0.25 μg/kg BW) (P<0.05). An infusion of 10 nmol of ghrelin into the medial basal hypothalamus (arcuate nucleus) significantly stimulated the release of GH in male calves (P<0.05). GH levels began to rise just after the infusions and peaked at 10 min, then decreased to the basal concentrations within 1 h after the injection. The present results show that ghrelin stimulates GH release in ruminants.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Regulatory Peptides - Volume 126, Issues 1â2, 15 March 2005, Pages 61-65
Journal: Regulatory Peptides - Volume 126, Issues 1â2, 15 March 2005, Pages 61-65
نویسندگان
Tsutomu Hashizume, Mami Horiuchi, Sumie Nonaka, Etsuko Kasuya, Masayasu Kojima, Hiroshi Hosoda, Kenji Kangawa,