Pharmacological Characteristics of Octopamine-Sensitive Adenylate Cyclase and N-Acetyl Octopamine Transferase in Insects

p-Octopamine (OA) occurs in the nervous systems of many invertebrates at much higher concentrations than in vertebrate tissues (Klemm, 1985). A variety of physiological effects have been ascribed to OA including modulation of the activity of excitable tissues in annelids (Tanaka and Webb, 1983), crustacea (Evans et al, 1987) and insects (Hoyle, 1975; Evans and O’Shea, 1978) and the induction of specific behavioural responses in nematodes (Horitz et al, 1982) and crustacea (Livingston et al, 1980; Bevengut and Clarac, 1982; Kravitz et al, 1981). In insects, OA has also been implicated in excitation of the firefly lantern (Carlson, 1986), stimulation of glycogenolysis in nerve cord and fat body (Robertson and Steele, 1972; Downer, 1979a,b). Stimulation of cardiac contraction (Collins and Miller, 1977), enhancement of substrate utilisation by flight muscle (Goosey and Candy, 1980), release of diacylglycerol from locust fat body (Orchard et al. 1982) and regulation of release of peptide hormones from the corpus cardiacum (Orchard et al., 1983; Downer et al., 1984).