|
| |
|
|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
Neurochemical fine tuning of a peripheral tissue: peptidergic and aminergic regulation of fluid secretion by Malpighian tubules in the tobacco hawkmoth M. sexta
1 Department of Zoology, Downing Street, University of Cambridge, Cambridge
CB2 3EJ, UK
2 Department of Zoology, Stockholm University, Svante Arrhenius väg 16,
SE-106 91 Stockholm, Sweden
3 Institute of Neuroscience, University of Oregon, Eugene, Oregon 97403
USA
* Author for correspondence (e-mail: shpm100{at}hermes.cam.ac.uk )
Accepted 15 April 2002
The actions of various peptides and other compounds on fluid secretion by Malpighian tubules in the tobacco hawkmoth Manduca sexta sexta are investigated in this study. Using a newly developed pharate adult Malpighian tubule bioassay, we show that three tachykinin-related peptides (TRPs), leucokinin I, serotonin (5-HT), octopamine, the cardioacceleratory peptides 1a, 1b and 2c, cGMP and cAMP each cause an increase in the rate of fluid secretion in pharate adult tubules. Whereas the possible hormonal sources of biogenic amines and some of the peptides are known, the distribution of TRPs has not been investigated previously in M. sexta. Thus we performed immunocytochemistry using an anti-TRP antiserum. We show the presence of TRP-like material in a small subset of cells in the M. sexta central nervous system (CNS). The larval brain contains approximately 60 TRP-immunopositive cells and there are approximately 100 such cells in the adult brain including the optic lobes. Every ganglion of the ventral nerve cord also contains TRP-like immunoreactive cells. No TRP-containing neurosecretory cells were seen in the CNS, but endocrine cells of the midgut reacted with the antiserum.
We propose the hypothesis that the control in insects of physiological systems by hormones may not always involve tissue-specific hormones that force stereotypical responses in their target systems. Instead, there may exist in the extracellular fluid a continuous broadcast of information in the form of a chemical language to which some or all parts of the body continuously respond on a moment-to-moment basis, and which ensures a more effective and efficient coordination of function than could be achieved otherwise.
Key words: Manduca sexta, Malpighian tubule, leucokinin, cardioacceleratory peptide, crustacean cardioactive peptide, CCAP, CAP, TRP, tachykinin-related peptide, fluid secretion
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati 
Twitter What's this?
Related articles in JEB:
This article has been cited by other articles:
|
|
 |
|
  S. Maddrell Insect homeostasis: past and future J. Exp. Biol., February 1, 2009; 212(3): 446 - 451. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. K. Loi and N. J. Tublitz Sequence and expression of the CAPA/CAP2b gene in the tobacco hawkmoth, Manduca sexta J. Exp. Biol., October 1, 2004; 207(21): 3681 - 3691. [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]
|
|
|
|
 |
|
 E. M. Blumenthal Regulation of chloride permeability by endogenously produced tyramine in the Drosophila Malpighian tubule Am J Physiol Cell Physiol, March 1, 2003; 284(3): C718 - C728. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. Cabrero, J. C. Radford, K. E. Broderick, L. Costes, J. A. Veenstra, E. P. Spana, S. A. Davies, and J. A. T. Dow The Dh gene of Drosophila melanogaster encodes a diuretic peptide that acts through cyclic AMP J. Exp. Biol., December 15, 2002; 205(24): 3799 - 3807. [Abstract] [Full Text] [PDF]
|
|
