Nakazato M, Yamaguchi H, Shiomi K, Date Y, Fujimoto S, Kangawa K, Matsuo H, Matsukura S
Third Department of Internal Medicine, Miyazaki Medical College, Japan.
Biochem Biophys Res Commun. 1994 Dec 30;205(3):1966-75. doi: 10.1006/bbrc.1994.2901.
Guanylin is a 15-amino acid peptide that acts on intestinal guanylate cyclase, thereby regulating intestinal fluid and electrolyte transport through the second messenger, cyclic GMP. Using synthetic rat guanylin, we prepared an antiserum that recognizes human and rat guanylin equally on a molar basis and developed a sensitive radioimmunoassay (RIA). The major endogenous guanylin molecule in human intestine and plasma is 10-kDa proguanylin, 15-amino acid guanylin being a minor component. Human guanylin is distributed widely from the duodenum to colon, the highest contents being in the ileum and proximal colon. The plasma concentration of immunoreactive guanylin in the normal individuals tested was 31.2 +/- 3.0 fmol/ml (mean +/- SE) and that in patients with chronic renal failure who were undergoing hemodialysis 7,924 +/- 2,140 fmol/ml. The RIA we established is a promising tool for clarifying the physiological functions and pathophysiological significance of guanylin in water and electrolyte homeostasis.
鸟苷素是一种由15个氨基酸组成的肽，作用于肠道鸟苷酸环化酶，从而通过第二信使环磷酸鸟苷调节肠道液体和电解质的转运。我们使用合成的大鼠鸟苷素制备了一种抗血清，该抗血清在摩尔基础上对人和大鼠鸟苷素具有同等的识别能力，并开发了一种灵敏的放射免疫测定法（RIA）。人肠道和血浆中的主要内源性鸟苷素分子是10 kDa的前鸟苷素，15个氨基酸的鸟苷素是次要成分。人鸟苷素广泛分布于从十二指肠到结肠的部位，含量最高的是回肠和近端结肠。在接受检测的正常个体中，免疫反应性鸟苷素的血浆浓度为31.2±3.0 fmol/ml（平均值±标准误），而在接受血液透析的慢性肾衰竭患者中为7924±2140 fmol/ml。我们建立的放射免疫测定法是阐明鸟苷素在水和电解质稳态中的生理功能及病理生理意义的一种有前景的工具。
