Hormonal control of tanning by the American cockroach: Cyclic AMP as a probable intermediate

Dibutyryl cyclic AMP mimics the action of bursicon by potentiating the darkening of ligated thoracic segments. Cyclic AMP also markedly increases the transport of radioactivity into the cuticle when injected simultaneously with UL-¹⁴C-tyrosine.Serotonin, another potential bursicon mimic, has no effect over a wide range of concentrations.It is speculated that bursicon activates membrane adenyl cyclase which produces cyclic AMP. The latter could subsequently increase membrane permeability or tyrosine hydroxylase activity.