Effects of 5-hydroxytryptamine on the Malpighian tubules of Aedes aegypti

https://doi.org/10.1016/0022-1910(88)90139-4Get rights and content

Abstract

The effects of 5-hydroxytryptamine, noradrenalin, adrenalin, octopamine and dopamine on the transepithelial voltage and fluid secretion of Malpighian tubules of Aedes aegypti were studied. Of these biogenic amines, only 5-hydroxytryptamine altered the transepithelial voltage. When applied in short pulses to superfused tubules, the transepithelial voltage depolarized rapidly and then hyperpolarized. The transepithelial resistance was reduced during both the depolarizing and hyperpolarizing phases of the response to 5-hydroxytryptamine. When added to the bathing saline at a concentration of 10−6 M, the transepithelial voltage showed a more complex response with both depolarizing and hyperpolarizing elements. 5-Hydroxytryptamine was also the only biogenic amine tested that increased fluid secretion. The maximal increase of fluid secretion in response to 5-hydroxytryptamine was small compared to that of crude head extract, containing the putative diuretic hormones of this species. The concentration of potassium in secreted fluid of Malpighian tubules stimulated by 5-hydroxytryptamine was decreased by 20mM, while the sodium concentration showed an increase of similar magnitude.

References (22)

  • W.H. Cliff et al.

    Renal proximal tubule of flounder II. Transepithelial Mg secretion

    Am. J. Physiol.

    (1986)
  • Cited by (44)

    • Hormonal regulation and functional role of the “renal” tubules in the disease vector, Aedes aegypti

      2021, Vitamins and Hormones
      Citation Excerpt :

      Therefore, it remains to be determined if 5HT may act through several pathways in A. aegypti that would involve multiple 5HT receptor subtypes or isoforms. Although both 5HT and DH31 work through similar signaling pathways, in adult A. aegypti, 5HT increases ion and fluid secretion without eliciting pronounced natriuretic activity (Sajadi et al., 2018; Veenstra, 1988). More recently, a study in adult female A. aegypti reported a moderate diuretic activity of 5HT, acting specifically as a kaliuretic hormone, selectivity secreting K+ (Sajadi et al., 2018).

    • Octopamine receptor gene expression in three lepidopteran species of insect

      2013, Peptides
      Citation Excerpt :

      This could be due to the fact that different stages of the life cycles were used in the two studies, and it is known that unlike adult tubules, the tubules of lepidopteran larvae exhibit high endogenous secretory activity and have no need for diuretic stimulation [10]. Still another study revealed the lack of octopaminergic action on the Malpighian tubules of the mosquito, Aedes aegypti [39], further highlighting the fact that octopaminergic control of Malpighian tubules is not uniform among insects. A high relative expression of the OARbeta1 receptor gene, the most highly expressed OAR in the T. ni Malpighian tubule when all genes are compared directly (Fig. 3), seen in all three of our test species indicates that this receptor is a good candidate for octopaminergic control in this tissue of lepidopteran larvae, rather than the OA/TA receptor that has been reported in other insects [6].

    • Water Homeostasis and Osmoregulation as Targets in the Control of Insect Pests

      2013, Advances in Insect Physiology
      Citation Excerpt :

      As immunohistochemical staining indicated that tyramine is synthesized in principal cells, its action as a paracrine hormone on the neighbouring stellate cells, where chloride conductance occurs, was suggested (Lange, 2009). Serotonin stimulated fluid secretion by isolated MTs of various insects including the mosquito A. aegypti (Clark and Dradley, 1998; Veenstra, 1988), the tobacco hornworm M. sexta (Skaer et al., 2002), the citrus swallowtail butterfly, Papilio demodocus (Nicolson and Millar, 1983), the locust, L. migratoria (Morgan and Mordue, 1984) and the house cricket A. domesticus (Coast, 2011). However, most studies on serotonin as a DH with a major regulatory role were conducted with the blood-gorging bug, R. prolixus as a model insect (Coast, 2009; Lange et al., 1989; Maddrell et al., 1969, 1991; Orchard, 2006).

    • Serotonin has kinin-like activity in stimulating secretion by Malpighian tubules of the house cricket Acheta domesticus

      2011, Peptides
      Citation Excerpt :

      However, whereas serotonin maximally stimulates secretion by R. prolixus MT, its activity in A. domesticus is about 25% of that achievable with either Achdo-DH or crude extracts of the CC. Similarly, in other insects (L. migratoria, C. vicina, A. aegypti, P. demodocus and M. sexta) serotonin activity is less (ranging from about 40% to 65%) than the maximum response to a DH present in tissue extracts or exogenous cAMP [27,28,36,37,42]. The diuretic activity of serotonin on cricket MT is similar to that reported for Achdo-KI [11].

    View all citing articles on Scopus

    Present address: Department of Biological Organic Chemistry (C.S.I.C.), Jorge Girona Salgado, 18–26, 08034 Barcelona, Spain.

    View full text