QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Wiehart, U. I. M. Articles by Schooley, D. A. Search for Related Content PubMed PubMed Citation Articles by Wiehart, U. I. M. Articles by Schooley, D. A. Social Bookmarking                         What's this?

The Journal of Experimental Biology 205, 493-501 (2002)
© 2002 The Company of Biologists Limited

Antagonistic control of fluid secretion by the Malpighian tubules of Tenebrio molitor: effects of diuretic and antidiuretic peptides and their second messengers

U. I. M. Wiehart¹, S. W. Nicolson^1,*, R. A. Eigenheer² and D. A. Schooley²

¹ Department of Zoology, University of Cape Town, Rondebosch 7701, South Africa and
² Department of Biochemistry, University of Nevada, Reno, NV 89503, USA

*Author for correspondence and present address: Department of Zoology and Entomology, University of Pretoria, Pretoria 0002, South Africa (e-mail: swnicolson{at}zoology.up.ac.za)

Accepted 28 November 2001

Fluid secretion by insect Malpighian tubules is controlled by haemolymph-borne factors. The mealworm Tenebrio molitor provides the first known example of antagonistic interactions between endogenous neuropeptides acting on Malpighian tubules. The two corticotropin-releasing-factor (CRF)-related diuretic peptides previously isolated from Tenebrio molitor, Tenmo-DH₃₇ and Tenmo-DH₄₇, were found to stimulate Tenebrio molitor tubules in vitro in a dose-dependent manner with EC₅₀ values of 0.12 nmol l^–1 and 26 nmol l^–1 respectively. However, no synergistic or additive effect was observed when these two peptides were tested simultaneously. We then investigated antagonism between second messengers: dose–response curves were constructed for stimulation of Tenebrio molitor tubules by cyclic AMP and their inhibition by cyclic GMP. When both cyclic nucleotides were included in the bathing Ringer, the stimulatory effect of cyclic AMP was neutralised by cyclic GMP. Similarly, the stimulatory effect of Tenmo-DH₃₇ was reversed on addition of an antidiuretic peptide (Tenmo-ADF), which was recently isolated from Tenebrio molitor and acts via cyclic GMP. The cardioacceleratory peptide CAP_2b, originally isolated from Manduca sexta, also increases intracellular cyclic GMP levels and inhibited fluid secretion by Tenebrio molitor tubules, with an EC₅₀ value of 85 nmol l^–1. This inhibitory effect was reversed by Tenmo-DH₃₇. Endogenous diuretic and antidiuretic peptides, effective at low concentrations and acting via antagonistic second messengers, have the potential for fine control of secretion rates in the Malpighian tubules of Tenebrio molitor.

Key words: diuretic peptide, antidiuretic peptide, cyclic AMP, cyclic GMP, antagonism, fluid secretion, Malpighian tubule, mealworm, Tenebrio molitor, Coleoptera.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				J.-P. Paluzzi, W. K. Russell, R. J. Nachman, and I. Orchard Isolation, Cloning, and Expression Mapping of a Gene Encoding an Antidiuretic Hormone and Other CAPA-Related Peptides in the Disease Vector, Rhodnius prolixus Endocrinology, September 1, 2008; 149(9): 4638 - 4646. [Abstract] [Full Text] [PDF]

				B. Li, R. Predel, S. Neupert, F. Hauser, Y. Tanaka, G. Cazzamali, M. Williamson, Y. Arakane, P. Verleyen, L. Schoofs, et al. Genomics, transcriptomics, and peptidomics of neuropeptides and protein hormones in the red flour beetle Tribolium castaneum Genome Res., January 1, 2008; 18(1): 113 - 122. [Abstract] [Full Text] [PDF]

				G. M. Coast, R. J. Nachman, and D. A. Schooley An antidiuretic peptide (Tenmo-ADFb) with kinin-like diuretic activity on Malpighian tubules of the house cricket, Acheta domesticus (L.) J. Exp. Biol., November 15, 2007; 210(22): 3979 - 3989. [Abstract] [Full Text] [PDF]

				V. P. Pollock, J. McGettigan, P. Cabrero, I. M. Maudlin, J. A. T. Dow, and S.-A. Davies Conservation of capa peptide-induced nitric oxide signalling in Diptera J. Exp. Biol., November 1, 2004; 207(23): 4135 - 4145. [Abstract] [Full Text] [PDF]

				R. C. Massaro, L. W. Lee, A. B. Patel, D. S. Wu, M.-J. Yu, B. N. Scott, D. A. Schooley, K. M. Schegg, and K. W. Beyenbach The mechanism of action of the antidiuretic peptide Tenmo ADFa in Malpighian tubules of Aedes aegypti J. Exp. Biol., July 15, 2004; 207(16): 2877 - 2888. [Abstract] [Full Text] [PDF]

				E. C. Johnson, L. M. Bohn, and P. H. Taghert Drosophila CG8422 encodes a functional diuretic hormone receptor J. Exp. Biol., February 15, 2004; 207(5): 743 - 748. [Abstract] [Full Text] [PDF]

				U. I. M. Wiehart, S. W. Nicolson, and E. Van Kerkhove K+ transport in Malpighian tubules of Tenebrio molitor L.: a study of electrochemical gradients and basal K+ uptake mechanisms J. Exp. Biol., March 15, 2003; 206(6): 949 - 957. [Abstract] [Full Text] [PDF]

				U. I. M. Wiehart, G. Klein, P. Steels, S. W. Nicolson, and E. Van Kerkhove K+ transport in Malpighian tubules of Tenebrio molitor L.: is a KATP channel involved? J. Exp. Biol., March 15, 2003; 206(6): 959 - 965. [Abstract] [Full Text] [PDF]