Format

Send to

Choose Destination
J Exp Biol. 1995 Aug;198(Pt 8):1647-53.

Fluid reabsorption and ion transport by the lower Malpighian tubules of adult female Drosophila.

Author information

1
Department of Biology, McMaster University, Hamilton, Ontario, Canada.

Abstract

The properties of the Malpighian tubules of Drosophila melanogaster change along their length. The upstream main segments secrete K(+)-rich fluid at a high rate. From this, the lower tubules reabsorb significant amounts of water and K+. Under stimulation, K+ reabsorption is accelerated. In addition, the lower tubules acidify the fluid passed to them by the main segments and secrete Ca2+ into it, adding to that transported there by the upstream epithelium. In contrast to the lumen-positive transepithelial potential difference (TEP) of the main segments, the TEP in the lower tubules is much lower and becomes lumen-negative close to their downstream junction with the common ureter. We suggest that the role of the lower tubule is to reduce the flow of K(+)-rich fluid that passes to the hindgut; this allows the hindgut to process the flow of excretory fluid more thoroughly.

PMID:
7636442
[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for HighWire
Loading ...
Support Center