Laboratorio de Neurobiología de Insectos, Centro Regional de Estudios Genómicos. Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Bvd 120 y 62 (1900), 1900 La Plata, Buenos Aires, Argentina.
Department of Anatomy, Physiology, and Pharmacology, University of Saskatchewan, Saskatoon, SK, Canada S7N 5E5.
J Exp Biol. 2019 May 22;222(Pt 10):jeb203000. doi: 10.1242/jeb.203000.
Given that hematophagous insects ingest large quantities of blood in a single meal, they must undergo a rapid post-prandial diuresis in order to maintain homeostasis. In the kissing bug (Hemiptera: Reduviidae), the coordinated activity of the Malpighian tubules and anterior midgut maintains water and ion balance during the post-prandial diuresis. Three to four hours after the meal, the diuretic process finishes, and the animal enters an antidiuretic state to ensure water conservation until the next blood intake. The diuretic and antidiuretic processes are tightly regulated by serotonin and neuropeptides in this insect. In the present work, we report that the neuropeptide precursor CCHamide2 is involved in the regulation of the post-prandial diuresis in Our results suggest a dual effect of RhoprCCHamide2 peptide, enhancing the serotonin-induced secretion by Malpighian tubules, and inhibiting serotonin-induced absorption across the anterior midgut. To our knowledge, this is the first report of a hormone presenting opposite effects in the two osmoregulatory organs (i.e. midgut and Malpighian tubules) in insects, probably reflecting the importance of a well-tuned diuretic process in hematophagous insects during different moments after the blood meal.
鉴于吸血昆虫在一次进食中会摄入大量血液，它们必须在餐后迅速利尿，以维持体内平衡。在接吻虫（半翅目：吸血蝽科）中，马氏管和前中肠的协调活动在餐后利尿过程中维持水和离子平衡。进食后 3 到 4 小时，利尿过程结束，动物进入抗利尿状态，以确保在下次摄入血液前保持水分。在这种昆虫中，血清素和神经肽严格调节利尿和抗利尿过程。在本工作中，我们报告 CCHamide2 神经肽前体参与调节餐后利尿。我们的结果表明 RhoprCCHamide2 肽具有双重作用，增强了马氏管中血清素诱导的分泌，抑制了前中肠中血清素诱导的吸收。据我们所知，这是昆虫中两种渗透调节器官（即中肠和马氏管）中激素呈现相反作用的第一个报道，这可能反映了在吸血昆虫进食后不同时间点，精心调节的利尿过程的重要性。
