Obtention of natural membranes enriched with GABAA receptor from disease vector insects (Aedes aegypti and Triatoma infestans)

FELSZTYNA, I; COLMANO, NG; TURINA, AV; SÁNCHEZ-BORZONE, ME; MIGUEL, V; GARCÍA, DA

Congreso; REUNIÓN CONJUNTA DE SOCIEDADES DE BIOCIENCIAS; 2017

γ-aminobuyricacid (GABA) is the major inhibitory neurotransmitter in thevertebrate CNS. Its specific receptor, the GABAA receptor (GABAA-R), is constituted by five subunits which compose a chloridechannel. In mammalian organisms there is a wide diversity of receptorsubunits, while in insects this variety is considerably minor, beingthe so-called RDL the most representative subunit. Consideringthat the receptor subunit composition is critical for the pharmacologicaland biophysical properties of GABAA-Rs, functional andstructural differences between receptors from mammals and insectsprovide multiple opportunities for the design of more selective andnon-toxic insecticides. Considering this argument, in the presentwork we obtained insect natural membranes as a sourceof GABAA-Rs to be used in the search of new insecticideagents. The membraneswere extracted from the head-thorax portion of 484 MEDICINA - Volumen 77 - (Supl. I),2017. A. aegypti larvae (IV stage) or T. infestans nymphs (V stage),by differentialcentrifugation procedures. Protein electrophoretic profiles contained inthe purified membranes showed bands with MW similar to those describedfor GABAA-Rs from other insects. In addition, we alsodetermined the presence of GABAA-Rs in thesamples by using radiolabeledligands which recognize specific sites in the receptor. All theseresults indicate that, through the procedures used in the work, it ispossible to obtain natural membranes enriched in native GABAA-Rs from insects, which could be utilized for theevaluation of compoundsable to block the receptor channel, with a consequent potentialinsecticidal activity.