Table I. Nitrate uptake activities of CHL1-injected Xenopus oocytes treated with PKA activators or a PKA inhibitor.

cAMP agonists	Percentage of control activity measured at
	150 µM	10 mM
Exp. 1	180	60
Exp. 2	206	41
Exp. 3	223	12
H89	Percentage of control activity measured at
	150 µM	10 mM
Exp. 1	62	139
Exp. 2	31	158
Exp. 3	0	185

The three experiments were performed in triplicate (samples of five oocytes) on three different batches of oocytes from different toads.