Department of Anatomy & Cell Biology, University of Melbourne, Parkville, Victoria, Australia.
Cell Tissue Res. 2011 Oct;346(1):135-9. doi: 10.1007/s00441-011-1240-4. Epub 2011 Sep 29.
Ghrelin, a peptide hormone from the stomach, has been recently discovered to reduce sodium excretion from the kidney. Although the effects on the kidney suggest actions in the distal nephron, the sites of expression of ghrelin receptors have not been localised. In the present work we have used a mouse that expresses green fluorescent protein under the control of the ghrelin receptor promoter to locate sites of receptor expression in the kidney. Receptor expression was confined to the straight parts of the distal tubules and the thin limbs of the loops of Henle. No expression was detected in other structures, including the glomeruli, proximal tubules and collecting ducts. Ghrelin receptors were not found in extra-renal or intra-renal arteries, despite observations that ghrelin is a vasodilator. The distribution revealed by in situ hybridisation histochemistry was the same as that revealed by the reporter. In conclusion, ghrelin receptors have a restricted distribution in the kidney. The location in the straight parts of the distal tubules accords with observations that ghrelin promotes sodium retention.
胃泌素，一种源自胃部的肽类激素，最近被发现可减少肾脏对钠的排泄。尽管对肾脏的影响表明其在远曲小管中起作用，但胃泌素受体的表达部位尚未确定。在本研究中，我们使用了一种在胃泌素受体启动子控制下表达绿色荧光蛋白的小鼠，以定位肾脏中受体的表达部位。受体表达仅限于远端小管的直部和Henle 袢的细段。在其他结构中未检测到表达，包括肾小球、近端小管和集合管。尽管观察到胃泌素是一种血管扩张剂，但在肾外或肾内动脉中均未发现胃泌素受体。原位杂交组织化学揭示的分布与报告基因揭示的分布相同。总之，胃泌素受体在肾脏中的分布受到限制。其在远端小管直部的位置与胃泌素促进钠潴留的观察结果一致。
