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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.