Macula densa cells in the distal nephron, according to the classic paradigm, are salt sensors
that generate paracrine chemical signals in the juxtaglomerular apparatus to control vital
kidney functions, including renal blood flow, glomerular filtration, and renin release. Renin is
the rate-limiting step in the activation of the renin-angiotensin system, a key modulator of
body fluid homeostasis. Here, we discuss recent advances in understanding macula densa
sensing and suggest these cells, in addition to salt, also sense various chemical and …