The substance that is a vasodilator elsewhere but causes vasoconstriction in kidneys (afferent aeriole) is:
Adenosine has 2 receptors - A1 & A2 A2 vasodilation (elsewhere) A1 vasoconstriction (kidney) Adenosine is a ligand, pa of the tubuloglomerular feedback. Macula densa cells sense the Na+ level in tubular fluids. Excess Na+ reaching macula densa cells Na+ / K+ ATPase pump in basolateral membranes transpo Na & K+ by degrading ATP Adenosine formed as a by product Adenosine acts as a ligand on the A1 receptors of afferent aeriole Constriction of afferent aerioles
Nitric oxide
Adenosine
Bradykinin
Endothelin
Excretory System (Kidney, Bladder) Acid-Base Balance