Ren Yilin, Garvin Jeffrey L, Liu Ruisheng, Carretero Oscar A
Division of Hypertension and Vascular Research, Henry Ford Hospital, 2799 West Grand Blvd., Detroit, MI, 48202, USA.
Pediatr Nephrol. 2009 Jan;24(1):31-5. doi: 10.1007/s00467-008-0852-8. Epub 2008 May 17.
In hypertension the pressure natriuresis set point is shifted to a higher pressure due to an increase in both renal vascular resistance and sodium (Na) reabsorption. The afferent arterioles (Af-Arts) and efferent arterioles (Ef-Arts) account for most renal vascular resistance; they control glomerular filtration rate (GFR) and peritubular pressure, and, consequently, renal function. Af-Art and Ef-Art resistance is regulated by factors similar to those in other arterioles and also by tubuloglomerular feedback (TGF). TGF operates via the macula densa, which senses increases in sodium chloride (NaCl) and sends a signal that constricts the Af-Art and dilates the Ef-Art. In the outer renal cortex, the connecting tubule (CNT) returns to the glomerular hilus and contacts the Af-Art. This morphology is compatible with cross-talk between the CNT and Af-Art, so-called connecting tubule glomerular feedback (CTGF). Our studies show that increasing NaCl delivery to the CNT results in Af-Art dilatation that can be blocked by inhibitors of Na transport. We believe cross-talk between the CNT and Af-Art is a novel mechanism that may contribute to regulation of renal blood flow and GFR.
在高血压中，由于肾血管阻力和钠（Na）重吸收增加，压力利尿设定点移至更高压力。入球小动脉（Af-Arts）和出球小动脉（Ef-Arts）构成了大部分肾血管阻力；它们控制肾小球滤过率（GFR）和肾小管周围压力，进而控制肾功能。Af-Art和Ef-Art阻力受与其他小动脉类似的因素调节，也受管球反馈（TGF）调节。TGF通过致密斑起作用，致密斑感知氯化钠（NaCl）增加并发出信号，使Af-Art收缩，Ef-Art舒张。在肾外皮质，连接小管（CNT）返回肾小球门并与Af-Art接触。这种形态与CNT和Af-Art之间的相互作用相一致，即所谓的连接小管肾小球反馈（CTGF）。我们的研究表明，增加向CNT输送的NaCl会导致Af-Art舒张，而这种舒张可被Na转运抑制剂阻断。我们认为CNT和Af-Art之间的相互作用是一种可能有助于调节肾血流量和GFR的新机制。
