Submitted on October 16, 2008
Revised on December 9, 2008
Accepted on December 9, 2008
Gap Junctional Intercellular Communication in the Juxtaglomerular Apparatus
Jian Yao1*, Takashi Oite2, and Masanori Kitamura3
1 Yamanashi University
2 Institute of Nephrology, Niigata University Graduate School of Medical and Dental Sciences
3 Interdisciplinary Grad Sch of Medicine and Engineering
* To whom correspondence should be addressed. E-mail: yao{at}yamanashi.ac.jp.
The juxtaglomerular apparatus (JGA) is a specialized contact region between the glomerulus and the cortical thick ascending limb that plays an active role in the maintenance of ion homeostasis and control of blood pressure. The JGA accommodates several different cell types including vascular smooth muscle cells, endothelial cells, mesangial cells, macula densa cells, and renin-secreting juxtaglomerular granular cells. These cells, with the exception of the macular densa cells, are tightly coupled by gap junctions. Gap junction-mediated intercellular communication in the JGA provides a pathway for signal transduction and coordination of multicellular functions. Disruption of cell-to-cell communication in the JGA results in altered preglomerular vascular tone and renin secretion. This review summarizes recent data about the roles of gap junctions in the JGA and illustrates how gap junction-mediated intercellular Ca2+ signals determine physiological responses in the JGA.
