Tubuloglomerular feedback is a process by which the concentration of NaCl in the lumen of the distal nephron regulates resistance of the afferent and efferent arterioles of glomeruli, hence adjusting glomerular capillary pressure. Glomerular capillary pressure is a key determinant of glomerular filtration, and thus urinary volume, Na excretion and blood pressure. The sensor of luminal NaCl concentration is a plaque of cells called the macula densa.
Dr.Liu’s group is studying several issues regarding tubuloglomerular feedback. First, it is examining how the macula densa acts as a transducer to sense a change in luminal NaCl concentration and produce the tubuloglomerular feedback signal. Second, the group is investigating the mechanism of regulation of NAD(P)H oxidase at the macula densa during tubuloglomerular feedback. Finally, it is examining how NO produced by nNOS in the macula densa alters this signal, and how nNOS is regulated.
Dr. Liu’s group utilizes state-of-the-art techniques such as microperfusion of kidney tubules and arterioles in vitro, micropuncture of kidney tubules in vivo, laser capture microdissection, molecular biology, cell biology, cell culture, whole-animal physiology, and knockout and transgenic mouse models.