Tesauro Manfredi, Schinzari Francesca, Caramanti Miriam, Lauro Renato, Cardillo Carmine
Department of Medicina Interna, Università di Tor Vergata, 00133 Rome, Italy.
Int J Pept. 2010;2010. doi: 10.1155/2010/864342. Epub 2010 Mar 16.
Ghrelin, an endogenous ligand for the growth hormone secretagogue receptor, is synthesized as a preprohormone and then proteolytically processed to yield a 28-amino acid peptide. This peptide was originally reported to induce growth hormone release; large evidence, however, has indicated many other physiological activities of ghrelin, including regulation of food intake and energy balance, as well as of lipid and glucose metabolism. Ghrelin receptors have been detected in the hypothalamus and the pituitary, but also in the cardiovascular system, where ghrelin exerts beneficial hemodynamic activities. Ghrelin administration acutely improves endothelial dysfunction by increasing nitric oxide bioavailability and normalizes the altered balance between endothelin-1 and nitric oxide within the vasculature of patients with metabolic syndrome. Other cardiovascular effects of ghrelin include improvement of left ventricular contractility and cardiac output, as well as reduction of arterial pressure and systemic vascular resistance. In addition, antinflammatory and antiapoptotic actions of ghrelin have been reported both in vivo and in vitro. This review summarizes the most recent findings on the metabolic and cardiovascular effects of ghrelin through GH-dependent and -independent mechanisms and the possible role of ghrelin as a therapeutic molecule for treating cardiovascular diseases.
胃饥饿素是生长激素促分泌素受体的内源性配体,它以前体激素的形式合成,然后经蛋白水解加工产生一种由28个氨基酸组成的肽。最初报道这种肽可诱导生长激素释放;然而,大量证据表明胃饥饿素还有许多其他生理活性,包括调节食物摄入和能量平衡以及脂质和葡萄糖代谢。已在下丘脑和垂体中检测到胃饥饿素受体,但在心血管系统中也有发现,胃饥饿素在该系统中发挥有益的血流动力学作用。急性给予胃饥饿素可通过增加一氧化氮生物利用度改善内皮功能障碍,并使代谢综合征患者血管系统中内皮素-1与一氧化氮之间失衡的状态恢复正常。胃饥饿素的其他心血管效应包括改善左心室收缩力和心输出量,以及降低动脉血压和全身血管阻力。此外,已在体内和体外报道了胃饥饿素的抗炎和抗凋亡作用。本综述总结了关于胃饥饿素通过依赖生长激素和不依赖生长激素的机制产生的代谢和心血管效应的最新研究结果,以及胃饥饿素作为治疗心血管疾病的治疗分子的可能作用。