Allatostatin-C antagonizes the synergistic myostimulatory effect of allatotropin and serotonin in Rhodnius prolixus (Stal)

MARIA JOSE VILLALOBOS SAMBUCARO; LUIS DIAMBRA; FERNANDO GABRIEL NORIEGA,; JORGE RAFAEL RONDEROS

GENERAL AND COMPARATIVE ENDOCRINOLOGY

ACADEMIC PRESS INC ELSEVIER SCIENCE

Lugar: Amsterdam; Año: 2016 vol. 233 p. 1 - 7

0016-6480

Haematophagous insects can ingest large quantities of blood in a single meal producing a large quantityof urine in the following hours to eliminate the excess of water and mineral ions incorporated. The excretoryactivity of the Malpighian tubules is facilitated by an increase in haemolymph circulation as a resultof the intensification of aorta contractions, combined with an increase of anterior midgut peristalticwaves. We have recently shown that haemolymph circulation during post-prandial diuresis is modulatedby the synergistic activity of allatotropin (AT) and serotonin, resulting in an increase in aorta and cropcontraction rates. In the present study we describe the antagonistic effect of allatostatin-C (AST-C) onthe increase of aorta frequency of contractions induced by serotonin/AT in Rhodnius prolixus. The administrationof AST-C counteracted the increase in the frequency induced by the treatment with serotonin/AT, but did not affect the increase in frequency induced by the administration of serotonin alone, suggestingthat AST-C is altering the synergism between serotonin and AT. Furthermore, the administration ofAST-C during post-prandial diuresis decreases the number of peristaltic waves of the anterior midgut.The AST-C putative receptor is expressed in the hindgut, midgut and dorsal vessel, three critical organsinvolved in post-prandial diuresis. All together these findings provide evidence that AST-C plays a keyrole as a myoregulatory and cardioregulatory peptide in R. prolixus.