Effect of basolateral application of extracellular nucleotides on different currents in leech dorsal integuments under control and apical Ca2+-free conditions
| . | ATP . | . | UTP . | . | Adenosine . | . | |||
|---|---|---|---|---|---|---|---|---|---|
| . | APW . | HSW . | APW . | HSW . | APW . | HSW . | |||
| Control conditions | |||||||||
| Isc (μA cm-2) | 23.10±2.48 | 18.60±3.22 | 11.30±1.12 | 9.50±1.38 | 14.50±2.30 | 13.0±1.40 | |||
| Iami (μA cm-2) | 13.50±1.02 | 14.30±2.68 | 2.76±1.16 | 5.76±1.46 | 5.15±1.58 | 3.80±0.70 | |||
| INa (μA cm-2) | 10.30±1.60 | 14.0±3.24 | 3.76±0.78 | 6.88±1.68 | 7.70±1.58 | 5.20±0.82 | |||
| RT (Ω cm2) | 3739±366 | 4221±330 | 8400±1615 | 6537±1816 | 5354±1259 | 3214±424 | |||
| Apical Ca2+-free conditions | |||||||||
| Isc (μA cm-2) | 27.10±4.58 | 31.62±3.24* | 19.20±6.44 | 17.95±2.70 | 19.40±1.86 | 16.62±2.04 | |||
| Iami (μA cm-2) | 22.10±1.52* | 24.50±3.54* | 11.40±1.94 | 10.20±1.30 | 8.20±1.30 | 6.76±1.56 | |||
| INa (μA cm-2) | 24.50±1.44* | 28.88±3.40* | 15.10±3.06 | 15.30±0.98 | 14.70±1.20* | 11.38±2.10 | |||
| RT (Ω cm2) | 2701±343 | 3028±394 | 5709±1067 | 4659±740 | 3980±708 | 3897±230 | |||
| . | ATP . | . | UTP . | . | Adenosine . | . | |||
|---|---|---|---|---|---|---|---|---|---|
| . | APW . | HSW . | APW . | HSW . | APW . | HSW . | |||
| Control conditions | |||||||||
| Isc (μA cm-2) | 23.10±2.48 | 18.60±3.22 | 11.30±1.12 | 9.50±1.38 | 14.50±2.30 | 13.0±1.40 | |||
| Iami (μA cm-2) | 13.50±1.02 | 14.30±2.68 | 2.76±1.16 | 5.76±1.46 | 5.15±1.58 | 3.80±0.70 | |||
| INa (μA cm-2) | 10.30±1.60 | 14.0±3.24 | 3.76±0.78 | 6.88±1.68 | 7.70±1.58 | 5.20±0.82 | |||
| RT (Ω cm2) | 3739±366 | 4221±330 | 8400±1615 | 6537±1816 | 5354±1259 | 3214±424 | |||
| Apical Ca2+-free conditions | |||||||||
| Isc (μA cm-2) | 27.10±4.58 | 31.62±3.24* | 19.20±6.44 | 17.95±2.70 | 19.40±1.86 | 16.62±2.04 | |||
| Iami (μA cm-2) | 22.10±1.52* | 24.50±3.54* | 11.40±1.94 | 10.20±1.30 | 8.20±1.30 | 6.76±1.56 | |||
| INa (μA cm-2) | 24.50±1.44* | 28.88±3.40* | 15.10±3.06 | 15.30±0.98 | 14.70±1.20* | 11.38±2.10 | |||
| RT (Ω cm2) | 2701±343 | 3028±394 | 5709±1067 | 4659±740 | 3980±708 | 3897±230 | |||
Values are means ± S.E.M., N=5.
Note that there are no significant differences between the artificial pondwater-adapted (APW) and high-salinity-adapted (HSW) integuments.
Isc, short-circuit current; Iami,amiloride-sensitive current; INa, transepithelial Na+ current; RT, transepithelial resistance.
Ca2+-free values significantly different from control values, P<0.05.