scholarly journals K+ transport in Malpighian tubules of Tenebrio molitor L.: is a KATP channel involved?

2003 ◽  
Vol 206 (6) ◽  
pp. 959-965 ◽  
Author(s):  
U. I. M. Wiehart
Keyword(s):  
Katp Channel ◽  
Tenebrio Molitor ◽  
Malpighian Tubules ◽  
K Transport

THE DISTRIBUTION OF RADIOACTIVE ARSENIC IN THE ORGANS OF POISONED INSECT LARVAE

1949 ◽  
Vol 27d (5) ◽  
pp. 265-269 ◽  
Author(s):  
F. O. Morrison ◽  
W. F. Oliver
Keyword(s):  
Arsenic Trioxide ◽  
Body Wall ◽  
Tenebrio Molitor ◽  
Malpighian Tubules ◽  
Insect Larvae

Radioactive arsenic trioxide, containing As76 injected in solution into the haemolymph of last instar Tenebrio molitor L. larvae, distributed itself throughout the haemolymph, body wall, fore-, mid-, and hindgut, and Malpighian tubules within one hour and showed little change in distribution after as much as 20 hr. even though most larvae remained alive. When injected into the gut it showed little sign of escaping. Fifty instar Phlegethontius quinoquemaculata Haw. larvae fed the dry active arsenic trioxide absorbed only very small amounts. The largest portion remained in the gut if the specimen died or was eliminated within 20 hr. if the specimen lived. As little as 10−11 gm. arsenic was detectable in the digested insect organs. The use of a dipping counter on aliquots of the acid tissue digest provides a simple and accurate means of counting samples and is to be recommended in studies of this nature.

scholarly journals Cold tolerance ofDrosophilaspecies is tightly linked to the epithelial K+transport capacity of the Malpighian tubules and rectal pads

2017 ◽  
Vol 220 (22) ◽  
pp. 4261-4269 ◽  
Author(s):  
Mads Kuhlmann Andersen ◽  
Heath A. MacMillan ◽  
Andrew Donini ◽  
Johannes Overgaard
Keyword(s):  
Cold Tolerance ◽  
Malpighian Tubules ◽  
Transport Capacity ◽  
K Transport

Intrinsic regulation of K+ transport in Malpighian tubules (Formica): Electrophysiological evidence

1992 ◽  
Vol 38 (6) ◽  
pp. 431-446 ◽  
Author(s):  
A. Leyssens ◽  
P. Steels ◽  
E. Lohrmann ◽  
R. Weltens ◽  
E. Van Kerkhove
Keyword(s):  
Malpighian Tubules ◽  
Electrophysiological Evidence ◽  
Intrinsic Regulation ◽  
K Transport

Analysis of epithelial K+ transport in Malpighian tubules ofDrosophila melanogaster: evidence for spatial and temporal heterogeneity

2001 ◽  
Vol 204 (13) ◽  
pp. 2289-2299 ◽  
Author(s):  
Mark R. Rheault ◽  
Michael J. O’Donnell
Keyword(s):  
Drosophila Melanogaster ◽  
Distal Segment ◽  
Malpighian Tubules ◽  
Unstirred Layer ◽  
Temporal Heterogeneity ◽  
Lower Segment ◽  
Spatial And Temporal Heterogeneity ◽  
Microelectrode Measurements ◽  
K Transport ◽  
Periodic Reduction

SUMMARYTransport of K+ by the lower, main and distal segments of the Malpighian tubules of Drosophila melanogaster was analyzed using self-referencing K+-selective microelectrodes. Transport properties of the Malpighian tubules of Drosophila melanogaster change along their length. Self-referencing ion-selective (SeRIS) microelectrode measurements (relative to the bath concentration of 20 mmoll−1) showed a 1% reduction (P<0.05) of [K+] in the unstirred layer adjacent to the main segment of the Malpighian tubules, confirming secretion of K+ from the bath to the tubule lumen. Conversely, SeRIS measurements showed a 0.7% increase (P<0.05) in [K+] in the unstirred layer adjacent to the lower segment of Malpighian tubules, confirming reabsorption of K+ from the luminal fluid to the bath. Measurements using SeRIS also showed that the distal segment neither secreted nor reabsorbed K+. There was pronounced spatial heterogeneity in K+ transport by the lower segment and the main segment; not all morphologically similar cells participated equally in K+ transport, nor did all main segment cells respond equally to stimulation of K+ transport by cyclic AMP. Pronounced temporal heterogeneity in K+ reabsorption by the lower Malpighian tubules was also observed. We suggest that this reflects periodic reduction in K+ reabsorption due to retention of fluid within the lower segment when the ureter contracts.

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