... electrophysiology Fluid secretion Kinins The transepithelial electrical resistance is easily measured in a planar epithelium as the ratio of the transepithelial voltage deflection consequent to a transepithelial current pulse at uniform current density (Ohm's law). The current density cannot be uniform...

...Geoffrey M. Coast SUMMARY The mechanism of primary urine production and the activity of a diuretic kinin, Achdo-KII, were investigated in Malpighian tubules of Acheta domesticus by measuring intracellular Na + , K + and Cl − activities, basolateral membrane voltage ( V b ), fluid secretion...

...Simon Maddrell SUMMARY Most of my work has been on the hormonal control of fluid secretion by insect Malpighian tubules. My present purpose is mostly to describe some previously unpublished results in this area and put them in context of what was already known. In this, I hope to draw attention...

... activity. * Author for correspondence (e-mail: [email protected] ) 3 9 2007 © The Company of Biologists Limited 2007 2007 Malpighian tubule fluid secretion ion transport electrophysiology diuretic hormone antidiuretic factor kinin neuropeptide The excretory process...

...N. J. V. Skaer; D. R. Nässel; S. H. P. Maddrell; N. J. Tublitz SUMMARY 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...

...U. I. M. Wiehart; S. W. Nicolson; R. A. Eigenheer; D. A. Schooley SUMMARY 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...

... 2001 © 2001 by Company of Biologists 2001 Drosophila melanogaster Malpighian tubule fluid secretion diuretic hormone calcitonin-like diuretic peptide muscakinin V-ATPase cyclic AMP Recently, Furuya et al. ( Furuya et al., 2000 ) described the isolation of two diuretic...

...J. A. Riegel; R. W. Farndale; S. H. P. Maddrell ABSTRACT Para -aminohippuric acid (PAH, 0.2 and 1 mmol l −1 ) had no effect on the basal fluid secretion rate (FSR) of isolated Malpighian tubules of Drosophila melanogaster Meig. and did not affect stimulation of the FSR induced by adenosine 3′,5...

... and 2,4-dinitrophenol (DNP). Both substances lowered the single glomerulus filtration fraction (SGFF), probably by affecting a fluid secretion mechanism. In addition, DNP diminished the flow-enhancing effect of adrenaline. This study provides relatively unequivocal evidence that fluid secretion underlies...

...J. A. Riegel; S. H. P. Maddrell; R. W. Farndale; F. M. Caldwell ABSTRACT External application of the 3′,5′-cyclic monophosphates of inosine, cytidine, uridine and thymidine stimulated the fluid secretion rate (FSR) of Malpighian tubules isolated from Drosophila melanogaster . The evidence suggested...

... with leucokinin, does not affect the potential profile across the principal cells, showing that chloride must pass through another route. The cell-permeant Ca 2+ chelator BAPTA-AM was shown to suppress the action of leucokinins (insect peptides that induce rapid fluid secretion), but not those of cyclic AMP...

... + ], and Sch28080 (10 −4 mol l −1 ), a K + /H + -ATPase inhibitor, were without effect on fluid secretion. Dihydro-ouabain was also without effect on electrical potential differences either in the absence or in the presence of Ba 2+ . Vanadate (10 −3 mol l −1 ), in contrast, strongly reduced fluid secretion...

...Geoffrey M. Coast; Iain Kay ABSTRACT Acheta diuretic peptide ( Acheta -DP) is a corticotropin-releasing factor (CRF)-related peptide found in head extracts of the house cricket Acheta domesticus . The peptide causes a dose-dependent increase in fluid secretion by cricket Malpighian tubules isolated...

... concentrations than do the upper tubules. During subsequent diuresis, regulation of the haemolymph potassium concentration depends on three cooperative homoeostatic mechanisms in the tubules. A fall in potassium concentration of the medium bathing the tubules causes (i) a decrease in the rate of fluid secretion...

... by Company of Biologists 1993 potassium ions sodium ions excretion fluid secretion Rhodnius prolixus salivary glands Calliphora vicina Malpighian tubules epithelial transport gramicidin D Insect epithelia such as the salivary glands of blowflies and the Malpighian tubules...

... postfeeding Manduca sexta larvae. However, Manduca-DH was reported to have no effect on Malpighian tubules in vitro . Manduca-DH and [Nle 2,11 ]- M anduca-DH were synthesized in Texas and assayed in London on isolated Malpighian tubules of Acheta domesticus. Man-duca-DH stimulated fluid secretion by about 60...

...Angela Wenning; U. T. E. Greisinger; Jacques P. Proux ABSTRACT Fluid secretion by isolated upper and lower portions of Malpighian tubules in the centipede Lithobius forficatus L. was studied. Ion requirements, cellular and transepithelial potentials, dependence on external osmolality...

...S. P. Nicholls ABSTRACT Fluid secretion by the Malpighian tubules of Libellula quadrimaculata is unusual in that it is dependent on sodium and entirely independent of potassium in the external medium. It is suggested that this is due to the primitive, sodium-rich haemolymph of the Odonata...