SALIVARY VASODILATORS OF AEDES-TRISERIATUS AND ANOPHELES-GAMBIAE (DIPTERA, CULICIDAE)

Salivary vasodilators of Aedes aegypti (L.) and Anopheles albimanus (W iedemann) were characterized previously as a tachykinin peptide and a catechol oxidase/peroxidase activity, respectively. To verify whether these two different vasodilators also were found in other distantly re lated members of each mosquito genus, we characterized the vasodilator s from A. triseriatus and A. gambiae. A. triseriatus salivary gland ho mogenates produced a reversible, endothelium dependent vasorelaxation of rabbit aortic rings constricted with norepinephrine, and contracted an isolated guinea pig ileum preparation. Additionally, the homogenat had no activity on both smooth muscle preparations when both tissues were desensitized previously by a large dose of substance P. Taken tog ether, these assays suggest the presence of a salivary tachykinin in A . triseriatus. A. gambiae salivary gland homogenates induced a slow va sodilation on both endothelium intact and endotheliumless preparations of aortic rings. A. gambiae homogenates also displayed catechol oxida se and peroxidase activity against o-dianisidine but not against serot onin, indicating the presence of an enzyme system slightly different f rom A. albimanus. We conclude that the presence of salivary tachykinin s or catechol/oxidase is not unique to A. aegypti or A. albimanus.