کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2007522 1066377 2007 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Adrenomedullin 2 (AM2)/intermedin is a more potent activator of hypothalamic oxytocin-secreting neurons than AM possibly through an unidentified receptor in rats
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
Adrenomedullin 2 (AM2)/intermedin is a more potent activator of hypothalamic oxytocin-secreting neurons than AM possibly through an unidentified receptor in rats
چکیده انگلیسی

Central administration of either adrenomedullin 2 (AM2) or adrenomedullin (AM) activates hypothalamic oxytocin (OXT)-secreting neurons in rats. We compared AM2 with AM, given intracerebroventricularly (icv), across multiple measures: (1) plasma OXT levels in conscious rats; (2) blood pressure, heart rate and circulating catecholamine levels in urethane-anesthetized rats; and (3) the expression of the c-fos gene in the supraoptic (SON) and the paraventricular nuclei (PVN). We also tested the effects of the AM receptor antagonist, AM22-52 and calcitonin gene-related peptide (CGRP) antagonist, CGRP8-37 on these measures. Plasma OXT levels at 10 min after icv injection of AM (1 nmol/rat) were increased (compared with vehicle), but OXT levels after AM2 (1 nmol/rat) were nearly double the levels seen after AM injection. OXT levels remained elevated at 30 min. Pretreatment with AM22-52 (27 nmol/rat) and CGRP8-37 (3 nmol/rat), nearly abolished the increase in plasma OXT level after AM injection, but partially blocked OXT level changes due to AM2. Increases in blood pressure, heart rate and circulating catecholamines were all greater in response to central AM2 than to AM at the same dose. In situ hybridization histochemistry showed that both AM2 and AM induced expression of the c-fos gene in the SON and the PVN, but AM22-52 + CGRP8-37 could only nearly abolish the effects of centrally administered AM. These results suggest that the more potent central effects of AM2 and only partial blockade by AM/CGRP receptor antagonists may result from its action on an additional, as yet unidentified, specific receptor in the central nervous system.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Peptides - Volume 28, Issue 5, May 2007, Pages 1104–1112
نویسندگان
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