Effects of aedeskinins and analogs on the basolateral membrane voltage (Vbl) of principal cells of Malpighian (renal) tubules of the adult yellow fever mosquito

Abstract

Diuresis is stimulated in the yellow fever mosquito Aedes aegypti by the kinin peptides. All three aedeskinins depolarize the transepithelial voltage (Vt) in Aedes Malpighian tubules (Veenstra et al., 1997), like leucokinin (Pannabecker et al., 1993). The effects of aedeskinin II and III, a synthetic analog 1460II, as well as leucokinin‐VIII (kinin of cockroach) on the basolateral membrane voltage (Vbl) of principal cells of Malpighian tubules of Aedes aegypti were studied. Both aedeskinins and synthetic analog 1460II hyperpolarized Vbl, similar to the effect of leucokinin‐VIII (expected from depolarization of Vt). Table 1 lists the peptides used in the present study.The kinin receptor agonist 1460 II was synthesized through the replacement of á amino acids with β amino to resist digestion by proteases. The substitution does not abolish voltage activity of the peptide, even though the substitution is within the conserved pentapeptide sequence F‐X‐X‐W‐Xa needed for diuretic action. The reversibility of the effects of 1460II indicates that the substitution does not bind the peptide irreversibly to the receptor. Supported by NSF Grant IOB‐0542797 to KWB.