QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

This Article Summary Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Schnizler, M. Articles by Clauss, W. Search for Related Content PubMed PubMed Citation Articles by Schnizler, M. Articles by Clauss, W.

Effects of extracellular purines on ion transport across the integument of Hirudo medicinalis

Mikael Schnizler^*, Mirjam Buss and Wolfgang Clauss

Institut für Tierphysiologie der Justus-Liebig-Universität Giessen, Wartweg 95, D-35392 Giessen Germany

View larger version (16K): [in a new window]   Fig. 1. Original recording of short-circuit current (Isc) from leech integument adapted to high-salinity water. Increasing concentrations of ATP (in mmol l-1) were added to the basolateral compartment at the indicated times. Note the weak decrease in Isc in response to 10 mmol l-1 ATP. The current sensitive to 100 µmol l-1 amiloride was determined before superfusion with Na+-free Ringer's solution; periods of superfusion are shown below the recording.

View larger version (27K): [in a new window]   Fig. 2. Effect of basolateral ATP on short-circuit current (Isc) of artificial pondwater (APW)- and high-salinity (HSW)-adapted integuments. Transepithelial Na+ current was determined after Isc had reached steady state (control). Subsequently 1 mmol l-1 ATP was added to the basolateral compartment and transepithelial Na+ current (INa) was determined again (ATP) when Isc had stabilized. Values are means ± S.E.M. (N=5). ATP significantly increased INa in HSW-adapted preparations, **P<0.005. Hatched columns, transepithelial Na+ current; filled columns, residual non-Na+ currents.

View larger version (11K): [in a new window]   Fig. 3. Original recording of short-circuit current (Isc) from high-salinity-adapted integument. Adenosine (1 mmol l-1) was added in increasing concentrations to the basolateral compartment to give the final concentrations (mmol l-1) indicated. The current sensitive to 100 µmol l-1 amiloride was determined before superfusion with Na+- free Ringer's solution; periods of superfusion are shown below the recording.

View larger version (25K): [in a new window]   Fig. 4. Effect of basolateral adenosine upon transepithelial currents of leech dorsal integuments. Integuments adapted to artificial pondwater (APW) or high-salinity (HSW) were clamped to 0 mV Transepithelial Na+ current (INa) was determined after equilibration (Control). Subsequently, 1 mmol l-1 adenosine was added to the basolateral compartment and, when the short-circuit current (Isc) had stabilized, INa was determined again (Adeno). Values are means ± S.E.M. (N=5). Addition of 1 mmol l-1 adenosine to the basolateral compartment significantly increased Isc but not INa in HSW-adapted integuments, **P<0.005. Hatched columns, transepithelial Na+ current; filled columns, residual non-Na+ currents.

View larger version (37K): [in a new window]   Fig. 5. Effect of apical 8-(4-chlorophenylthio)-cyclic AMP (cAMP) on short-circuit current (Isc) of artificial pondwater (APW)-adapted or high-salinity (HSW)-adapted leech integuments under apical Ca2+-free conditions. Ca2+ was removed from the apical compartment and, when Isc had stabilized, transepithelial Na+ current (INa) and non-Na+ currents were determined (Control). cAMP (100 µmol l-1) and 3-isobutyl-1-methyl-xanthine (1 mmol l-1) were added. INa was determined by apical perfusion with Na+-free Ringer (cAMP). Values are means ± S.E.M. (N=6). Hatched columns, INa; filled columns, residual non-Na+ currents.