The effect of biogenic amines and their analogs on carbohydrate metabolism in the fat body of the cockroach Blaberus discoidalis

Several biogenic amines and their analogs were examined for stimulatory effects on glycogen phosphorylase activity and trehalase biosynthesis in fat body of the cockroach, Blaberus discoidalis. Octopamine and synephrine were the most potent activators of fat body phosphorylase; 10 mu M octopamine being nearly as effective as the hypertrehalosemic hormone (HTH). Epinephrine, norepinephrine, and tyramine produced intermediate effects, whereas dopamine, 5-hydroxy tryptamine, and melatonin had no effect. The fat body octopamine receptors appeared to be pharmacologically related to vertebrate alpha-adrenergic receptors and belonged to the Octopamine(1) class receptor. In contrast to previous reports, synephrine also induced both phosphorylase activation and hypertrehalosemia as effectively as octopamine. Demethylchlordimeform, a formamidine insecticide structurally similar to octopamine, also strongly activated fat body phosphorylase, possibly by interaction with the octopamine receptor. (C) 1998 Academic Press.