title: Rhodnius prolixus Malpighian tubules and control of diuresis by neurohormones.
abstract: Rhodnius prolixus Malpighian tubules (MTs) are a good model for fluid and ion secretion studies in view of the dramatic postprandial diuresis, which follows its massive blood meals. Ingestion of a blood meal equals to 10-12 times their initial body mass, leads to rapid activation of high output by excretory system, which eliminates 40-50% of the fluid mass. Secretion of ions and water is stimulated 1000-fold by serotonin and diuretic hormone. These hormones cooperate synergistically to activate adenylate cyclase activity from MTs cells, which increase the level of intracellular cAMP. The anti-diuretic hormones have also an important role in the fluid maintenance of Rhodnius prolixus. Several hours after insect feeding occurs a reduction in urine flow, that has been thought to result from a decreased diuretic hormone release or from a novel mechanism of anti-diuresis involving insect cardioacceleratory peptide 2b (CAP2b) and cyclic GMP. In this article it is discussed how the hormone regulation of fluid transport is done in Rhodnius prolixus MTs.
authors.affiliation: CCS, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, 21949-900, Brasil.
authors.forename: Sabrina V
authors.initials: SV
authors.lastname: Martini
authors.forename: Suzete B
authors.initials: SB
authors.lastname: Nascimento
authors.forename: Marcelo M
authors.initials: MM
authors.lastname: Morales
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000378:metabolism; D000818:Animals; D000242:Cyclic AMP / Q000378:metabolism; D004231:Diuresis / Q000502:physiology*; D007301:Insect Hormones / Q000378:metabolism*; D017136:Ion Transport / Q000502:physiology; D007705:Kinins / Q000378:metabolism; D008317:Malpighian Tubules / Q000378:metabolism / Q000502:physiology*; D009479:Neuropeptides / Q000378:metabolism; D012239:Rhodnius / Q000378:metabolism / Q000502:physiology*; D012701:Serotonin / Q000378:metabolism
chemical_list: D007301:Insect Hormones; D007705:Kinins; D009479:Neuropeptides; C058620:crustacean cardioactive peptide; D012701:Serotonin; D000324:Adrenocorticotropic Hormone; D000242:Cyclic AMP