Figure 2.

Proposed functions of select renal olfactory receptors. (A) Olfr78 responds to short chain fatty acids in the peripheral vasculature and the afferent (aff) arteriole to increase BP and promote renin release. Within the macula densa (MD), adenylate cyclase 3 (AC3) has also been linked to an increase in renin release and GFR. Olfr90 has been localized to a MD cell line and may be involved in these processes. (B) Olfr691, localized within the proximal tubule (PT) and Olfr558 (localized to the juxtaglomerular apparatus; JGA) both respond to isovaleric acid (IVA). Under conditions of isovaleric acidemia, these receptors may be involved in bicarbonate secretion and BP regulation. (C) Olfr1393 has been localized within the PT where it contributes to the maintenance of glucose homeostasis via the sodium glucose co-transporters. Its function is exacerbated under conditions of type 1 or type 2 diabetes.