Ghrelin (rat), a growth hormone-releasing peptide first discovered in rat stomach in 1999, is a ligand for the growth hormone secretagogue receptor[1，2].
Retroperitoneal (RP) adipocytes were cultured in the absence or presence of either Ghrelin (rat) or desacyl Ghrelin (rat) and in combination with either inhibitors of protein synthesis, insulin, dexamethasone (DXM), or GHSR1a antagonist. The results indicate that both Ghrelin (rat) forms possess a direct leptin-releasing activity (LRA) on RP adipocytes and significantly enhanced adipocyte ob mRNA expression[4].
Ghrelin (rat) and the GHS-R1α receptor antagonist GHRP-6 were injected intravenously in rats followed by blood flow measurements using a microsphere technique. Ghrelin (rat) decreased, while GHRP-6 in fasted, but not fed, rats selectively increased islet blood flow fourfold[3]. The initial electrophysiological results displayed that ex vivo administration of Ghrelin (rat) increased NAc shell output in brain slices from drug- and training-na?ve rats. In rats with an acquired skilled reach performance, acute as well as repeated treatment with a Ghrelin (rat) receptor (GHSR-1 A) antagonist decreased the number of sucrose pellets consumed[5]. Ghrelin (rat) administration attenuated sepsis symptoms induced by CLP. Blood flow in the stomach greater curvature was significantly higher in the CLP induced sepsis group rats compared with the sham operation group, whereas there was no difference between the CLP group treated with Ghrelin (rat) and the sham rats. Ghrelin (rat) administration also reduced the secretion of pro inflammatory cytokines compared with the CLP induced sepsis group rats[6]. Ghrelin (rat) signaling increases the reward from social interaction in a manner that reflects the degree of divergence in body weight between the social pair[7].
References:
[1]. Tokudome T, Kangawa K. Physiological significance of ghrelin in the cardiovascular system. Proc Jpn Acad Ser B Phys Biol Sci. 2019;95(8):459-467. doi: 10.2183/pjab.95.032. PMID: 31611501; PMCID: PMC6819151.
[2]. Kojima M, Hosoda H, et,al.in is a growth-hormone-releasing acylated peptide from stomach. Nature. 1999 Dec 9;402(6762):656-60. doi: 10.1038/45230. PMID: 10604470.
[3]. Drott CJ, Franzén P, et,al. Ghrelin in rat pancreatic islets decreases islet blood flow. Am J Physiol Endocrinol Metab. 2019 Jul 1;317(1):E139-E146. doi: 10.1152/ajpendo.00004.2019. Epub 2019 May 7. PMID: 31063397.
[4]. Giovambattista A, Gaillard RC, et,al.Ghrelin gene-related peptides modulate rat white adiposity. Vitam Horm. 2008;77:171-205. doi: 10.1016/S0083-6729(06)77008-X. PMID: 17983857.
[5]. Vestlund J, Bergquist F, et,al. Ghrelin signalling within the rat nucleus accumbens and skilled reach foraging. Psychoneuroendocrinology. 2019 Aug;106:183-194. doi: 10.1016/j.psyneuen.2019.04.008. Epub 2019 Apr 8. PMID: 30999229.
[6]. Li B, Lin Q, et,al.Ghrelin regulates sepsis?induced rat acute gastric injury. Mol Med Rep. 2019 Jun;19(6):5424-5432. doi: 10.3892/mmr.2019.10208. Epub 2019 Apr 30. PMID: 31059095; PMCID: PMC6522907.
[7]. Schéle E, Pfabigan DM, et,al. Ghrelin Induces Place Preference for Social Interaction in the Larger Peer of a Male Rat Pair. Neuroscience. 2020 Nov 1;447:148-154. doi: 10.1016/j.neuroscience.2020.01.027. Epub 2020 Feb 5. PMID: 32032669.
Ghrelin (rat) 是一种生长激素释放肽，于 1999 年首次在大鼠胃中发现，是生长激素促分泌素受体[1，2] 的配体。
腹膜后 (RP) 脂肪细胞在生长素释放肽（大鼠）或去酰基生长素释放肽（大鼠）不存在或存在的情况下进行培养，并结合蛋白质合成抑制剂、胰岛素、地塞米松 (DXM) 或 GHSR1a 拮抗剂。结果表明，两种Ghrelin（大鼠）形式均对RP脂肪细胞具有直接的瘦素释放活性（LRA），并显着增强脂肪细胞ob mRNA的表达[4]。
在大鼠体内静脉注射 Ghrelin（大鼠）和 GHS-R1α 受体拮抗剂 GHRP-6，然后使用微球技术测量血流量。 Ghrelin（大鼠）减少，而 GHRP-6 在禁食但未进食的大鼠中选择性地使胰岛血流量增加四倍[3]。最初的电生理学结果表明，Ghrelin（大鼠）的离体给药增加了未接受药物和训练的大鼠脑切片中的 NAc 壳层输出。在具有后天熟练触及能力的大鼠中，用 Ghrelin（大鼠）受体 (GHSR-1A) 拮抗剂进行急性和重复治疗可减少消耗的蔗糖颗粒数量[5]。 Ghrelin（大鼠）给药减轻了 CLP 引起的败血症症状。与假手术组相比，CLP 引起的脓毒症组大鼠胃大弯的血流量显着高于假手术组，而 Ghrelin（大鼠）治疗的 CLP 组与假手术大鼠之间没有差异。与 CLP 诱导的脓毒症组大鼠相比，Ghrelin（大鼠）给药也减少了促炎细胞因子的分泌[6]。生长素释放肽（大鼠）信号以一种反映社交对之间体重差异程度的方式增加社交互动的奖励[7]。