hill plots of these data gave gradients close to unity , indicating a lack of co-operative site interactions.4 the monovalent cations , sodium and potassium , and the divalent cation , calcium , produced concentration-dependent decreases in [ ( 3 ) h ] -clonidine binding to membranes prepared from renal cortex , the ec ( 50 ) s being respectively 25 mm , 37 mm and 23 mm.5 at low concentrations the divalent cations , magnesium ( 1 mm ) and manganese ( 0.1 mm ) , produced enhancement of [ ( 3 ) h ] -clonidine binding .
C0007449
monovalent cations
C0033727
h