title: Influence of octopamine on trehalase activity in muscle and hemolymph of the American cockroach, Periplaneta americana L.
abstract: Injection of adult male cockroaches (Periplaneta americana) with 10 microliter 1 microM octopamine causes elevated activity of trehalase (alpha, alpha-trehalose glucohydrolase; EC 3.2.1.28) in hemolymph and muscle but not in gut. Tyramine, dopamine and glutamate, at the same concentration, failed to elicit any effect on trehalase activity. Determination of some kinetic parameters for muscle and hemolymph trehalases reveal that octopamine causes an increase in Vmax without any significant alteration in the Km of the enzyme for trehalose. The results are discussed in terms of the physiological significance of octopamine-mediated activation of tissue trehalases.
mesh_terms: D000818:Animals; D003058:Cockroaches; D004064:Digestive System / Q000201:enzymology; D006458:Hemolymph / Q000201:enzymology*; D007700:Kinetics; D009132:Muscles / Q000201:enzymology*; D009655:Octopamine / Q000494:pharmacology*; D014198:Trehalase / Q000378:metabolism*
chemical_list: D009655:Octopamine; C028435:2-octopamine; D014198:Trehalase