Rafaeli A, Pines M, Stern P S, Applebaum S W
Gen Comp Endocrinol. 1984 Apr;54(1):35-42. doi: 10.1016/0016-6480(84)90195-3.
Endogenous cyclic-AMP concentrations in Malpighian tubules of locusts increase as a result of diuretic hormone stimulation, and the level of increase is shown to be dependent on basal intracellular levels of cyclic-AMP. Furthermore, the increase in endogenous cyclic-AMP is in such excess as to cause excretion of high levels of cyclic-AMP in the urine.