Lai Feng J, Hsieh Ming C, Hsin Shih C, Lin Shiu R, Guh Jinn Y, Chen Hung C, Shin Shyi J
Graduate Institute of Medicine, Kaohsiung Medical University, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.
J Histochem Cytochem. 2002 Nov;50(11):1501-8. doi: 10.1177/002215540205001110.
Increased intrarenal atrial natriuretic peptide (ANP) mRNA expression has been reported in several disorders. To further investigate the action of renal ANP, we need to elucidate the exact site of its alteration in diseased kidneys. ANP mRNA and ANP were detected by in situ hybridization and immunohistochemistry in the kidneys from five normal and five diabetic rats. Renal ANP mRNA in eight normal and nine diabetic rats was measured by RT-PCR with Southern blot hybridization. In normal and diabetic rats, the distribution of ANP mRNA and ANP-like peptide was mainly located in proximal, distal, and collecting tubules. However, diabetic rats had significant enhancement of ANP mRNA and ANP-immunoreactive staining in the proximal straight tubules, medullary thick ascending limbs, and medullary collecting ducts. ANP mRNA in the outer and inner medulla of nine diabetic rats increased 5.5-fold and 3.5-fold, but only 1.8-fold in the renal cortex. This preliminary study showed that ANP mRNA and ANP immunoreactivity in proximal straight tubules, medullary thick ascending limb, and medullary collecting ducts apparently increased in diabetic kidneys. These findings imply that ANP synthesis in these nephrons may involve in adaptations of renal function in diabetes.
在多种疾病中均有肾内心房利钠肽（ANP）mRNA表达增加的报道。为进一步研究肾脏ANP的作用，我们需要阐明其在患病肾脏中发生改变的确切部位。通过原位杂交和免疫组化方法，对5只正常大鼠和5只糖尿病大鼠的肾脏进行检测，以测定ANP mRNA和ANP。采用逆转录聚合酶链反应（RT-PCR）及Southern印迹杂交法，对8只正常大鼠和9只糖尿病大鼠的肾ANP mRNA进行检测。在正常大鼠和糖尿病大鼠中，ANP mRNA和ANP样肽的分布主要位于近端小管、远端小管和集合管。然而，糖尿病大鼠近端直小管、髓袢升支粗段和髓质集合管中的ANP mRNA及ANP免疫反应性染色显著增强。9只糖尿病大鼠外髓质和内髓质中的ANP mRNA分别增加了5.5倍和3.5倍，但肾皮质中仅增加了1.8倍。这项初步研究表明，糖尿病肾脏中近端直小管、髓袢升支粗段和髓质集合管中的ANP mRNA及ANP免疫反应性明显增加。这些发现提示，这些肾单位中ANP的合成可能参与了糖尿病时肾功能的适应性变化。
