Figure 2.

Diagram depicting renal blood flow autoregulatory tubuloglomerular feedback (TGF) and myogenic responses. Afferent arteriolar vascular smooth muscle cell depicts contribution of 20-HETE to myogenic and TGF responses. Increased afferent arteriolar transmural pressure triggers the myogenic response to increase 20-HETE levels. 20-HETE causes afferent arteriolar constriction via inhibition of large-conductance Ca²⁺-activated K⁺ channels and activation of L-type Ca²⁺ channels. TGF response is initiated by sensing cells at the macula densa resulting in release of adenosine and ATP. Adenosine activates adenosine type A1 receptors to increase intracellular Ca²⁺ and ATP activates purinergic P2X receptors to increase 20-HETE levels resulting in afferent arteriolar constriction.