K+ transport in the caterpillar intestine epithelium: role of osmolytes for the K+-secretory capacity of the tobacco hornworm midgut
DC Field | Value | Language |
---|---|---|
dc.contributor.author | Meyer, H | |
dc.contributor.author | Wieczorek, H | |
dc.contributor.author | Zeiske, W | |
dc.date.accessioned | 2021-12-23T15:59:47Z | - |
dc.date.available | 2021-12-23T15:59:47Z | - |
dc.date.issued | 2004 | |
dc.identifier.issn | 01741578 | |
dc.identifier.uri | https://osnascholar.ub.uni-osnabrueck.de/handle/unios/4137 | - |
dc.description.abstract | The midgut of the tobacco hornworm, Manduca sexta, actively secretes potassium ions. This can be measured as short-circuit current (I-SC) with the midgut mounted in an Ussing chamber and superfused with a high-K+ saline containing as its major osmolyte 166 mM sucrose. Iso-osmotic substitution of sucrose by non-metabolisable compounds (mannitol, urea, NaCl and the polyethylene glycols 200, 400 and 600) led to a dramatic, though reversible, drop in the current. Acarbose, a specific inhibitor of invertase (sucrase) in vertebrates and insects, had no detectable influence on I-SC. Unexpectedly, after replacing sucrose iso-osmotically with the saccharides glucose, fructose, trehalose or raffinose, the K+ current could no longer be supported. However, all osmolytes smaller than sucrose (except for NaCl), metabolisable or not, initiated an immediate quite uniform but transient, increase in I-SC by about 20%, before its eventual decline far below the control value. Hypo-osmotic treatment by omission of sucrose also transiently increased the K+ current. Small osmolytes substituted for sucrose caused no transient I-SC stimulation when the epithelium had been challenged before with hypo-osmolarity; however, the eventual decline in I-SC could not be prevented. Our data seem inconsistent with a role of sucrose as energiser or simple osmolyte. Rather, we discuss here its possible role as analogous to that of sucrose in lower eukaryotes or plants, as an extra- and/or intracellular ``compatible osmolyte'' that stabilises structure and/or function of the proteins implicated in K+ transport. | |
dc.language.iso | en | |
dc.publisher | SPRINGER HEIDELBERG | |
dc.relation.ispartof | JOURNAL OF COMPARATIVE PHYSIOLOGY B-BIOCHEMICAL SYSTEMS AND ENVIRONMENTAL PHYSIOLOGY | |
dc.subject | ACTIVE-TRANSPORT | |
dc.subject | CARBOHYDRATE | |
dc.subject | FLUX | |
dc.subject | K+ secretion | |
dc.subject | LEPIDOPTERAN MIDGUT | |
dc.subject | Manduca sexta | |
dc.subject | MANDUCA-SEXTA L | |
dc.subject | METABOLISM | |
dc.subject | osmolyte | |
dc.subject | Physiology | |
dc.subject | PLASMA-MEMBRANE | |
dc.subject | POTASSIUM-TRANSPORT | |
dc.subject | PROTON PUMP | |
dc.subject | STIMULATION | |
dc.subject | sucrose | |
dc.subject | tobacco hornworm | |
dc.subject | Zoology | |
dc.title | K+ transport in the caterpillar intestine epithelium: role of osmolytes for the K+-secretory capacity of the tobacco hornworm midgut | |
dc.type | journal article | |
dc.identifier.doi | 10.1007/s00360-004-0441-5 | |
dc.identifier.isi | ISI:000224640100003 | |
dc.description.volume | 174 | |
dc.description.issue | 7 | |
dc.description.startpage | 527 | |
dc.description.endpage | 539 | |
dc.contributor.orcid | 0000-0002-3304-4523 | |
dc.identifier.eissn | 1432136X | |
dc.publisher.place | TIERGARTENSTRASSE 17, D-69121 HEIDELBERG, GERMANY | |
dcterms.isPartOf.abbreviation | J. Comp. Physiol. B-Biochem. Syst. Environ. Physiol. | |
crisitem.author.dept | FB 05 - Biologie/Chemie | - |
crisitem.author.deptid | fb05 | - |
crisitem.author.parentorg | Universität Osnabrück | - |
crisitem.author.netid | WiHe990 | - |