Department of Physiology, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu 807-8555, Japan.
J Physiol Sci. 2010 Jan;60(1):19-25. doi: 10.1007/s12576-009-0062-6. Epub 2009 Sep 18.
Ghrelin is a potent, centrally acting orexigenic hormone. Recently, we showed that centrally administered ghrelin is a potent antidipsogenic hormone in 24-h water deprived rats. In this study, we examined the effect of intracerebroventricular (icv) injection of ghrelin on angiotensin II (AII)-induced water intake in rats. We also examined the effects of icv injection of ghrelin on drinking induced by intraperitoneal injection of an isotonic polyethylene glycol (PEG) solution that causes isotonic hypovolemia. Water intake induced by the icv injection of AII or ip injection of PEG was significantly reduced after icv injection of ghrelin, although food intake was stimulated by the hormone. The drinking induced by AII was also inhibited by the icv administration of 4alpha-phorbol 12, 13-didecanoate, an agonist of the osmosensitive TRPV4 channel. This study showed that ghrelin is a potent antidipsogenic peptide by antagonizing general dipsogenic mechanisms including those activated by AII and hypovolemia in rats.
胃饥饿素是一种有效的、中枢作用的食欲肽激素。最近，我们发现，给予中枢的胃饥饿素是 24 小时限水大鼠强有力的抗利尿激素。在这项研究中，我们研究了脑室内（icv）注射胃饥饿素对血管紧张素Ⅱ（AII）诱导的大鼠饮水量的影响。我们还研究了脑室内注射胃饥饿素对腹腔内注射等渗聚乙二醇（PEG）溶液引起的等渗性低血容量诱导的饮水的影响。尽管该激素刺激了食物摄取，但 AII 的 icv 注射或 ip 注射 PEG 诱导的水摄入量明显减少。AII 诱导的饮水也被 osmosensitive TRPV4 通道激动剂 4alpha-佛波醇 12,13-癸酸酯的 icv 给药所抑制。这项研究表明，胃饥饿素通过拮抗包括 AII 和低血容量激活的一般利尿机制，是一种有效的抗利尿肽。
