Fig 1.
Inhibitory effect of SNAP on the basolateral 10-pS Cl- channel in the TAL.
(A) Representative single channel traces of the basolateral 10-pS Cl- channel at a holding potential of -60 mV in the control and during successive exposure to different concentration of SNAP (2.5–10 μM) from the same patch in cell-attached configuration. The channel closed level is indicated by the dotted line and “C”. (B) Statistical summary for dose-response effect of SNAP on the 10-pS Cl- channels from 5 sets of experiments. Each set of experiment was obtained by successive exposure to different concentration of SNAP (2.5–10 μM) from the same patch. Asterisk indicates the significant difference between the control (no SNAP) and SNAP treated groups. (*: P < 0.05, **: P < 0.01, ***:P < 0.001, paired sample t-test). (C) The curve is the best fit to percentage of inhibition (Eq 3) against the [SNAP] according to the Hill equation (Eq 2) with IC50 = 6.62 μM.
Fig 2.
Scavenging NO diminishes the inhibitory effect of SNAP on the 10-pS Cl- channels.
(A) A set of singe channel recordings from the same patch in a cell-attached patch under control condition, in the presence of 10 μM carboxy-PTIO alone as well as in the presence of 10 μM carboxy-PTIO + 5 μM SNAP. The holding potential was −60 mV and the channel closed level is indicated by the dotted line and “C”. (B) Statistical summary showing that carboxy-PTIO abolishes the inhibitory effect of SNAP on the channels (n = 6).
Fig 3.
Soluble guanylyl cyclase (sGC) inhibitor ODQ blocks the inhibitory effect of SNAP on the 10-pS Cl- channels in the TAL.
(A) Representative single channel recordings from the same cell-attached patch under control condition, in the presence of 10 μM ODQ alone as well as in the presence of both ODQ (10 μM) and SNAP (5 μM). The holding potential was −60 mV and the channel closed level is indicated by the dotted line and “C”. (B) The bar graph showing that ODG abolishes the inhibitory effect of SNAP on the channels (n = 5).
Fig 4.
Soluble guanylyl cyclase inhibitor LY-83583 prevents the effect of SNAP on the 10-pS Cl- channels.
(A) Representative single channel recordings from the same cell-attached patch under control condition, in the presence of 10 μM LY-83583 alone as well as in the presence of both LY-83583 (10 μM) and SNAP (5 μM). The holding potential was -60 mV and the channel closed level is indicated by the dotted line and “C”. (B) The bar graph showing that LY-83583 eliminates the inhibitory effect of SNAP on the channel.
Fig 5.
Inhibition of PKG abolishes the effect of SNAP on the 10-pS Cl- channels in the TAL.
(A) Representative single channel recordings from the same cell-attached patch under control condition, in the presence of 10 μM KT5823 alone as well as in the presence of both KT5823 (10 μM) and SNAP (5 μM). The holding potential was -60 mV and the channel closed level is indicated by the dotted line and “C”. (B) The bar graph showing that KT5823 eliminates the inhibitory effect of SNAP on the channel.
Fig 6.
Inhibition of PDE2 fails to abolish the effect of SNAP on the 10-pS Cl- channels in the TAL.
(A) Representative single channel recordings from the same cell-attached patch under control condition, in the presence of 10 μM BAY-60-7550 alone as well as in the presence of both BAY-60-7550 (10 μM) and SNAP (5 μM). The holding potential was -60 mV and the channel closed level is indicated by the dotted line and “C”. (B) The bar graph showing that BAY-60-7550 plays no role in the inhibitory effect of SNAP on the 10-pS Cl- channels.
Fig 7.
Signaling cascade for Inhibitory effect of SNAP on the 10-pS Cl- channel in TAL.
Carboxy-PTIO is a NO scavenger, ODQ or LY-83583 blocks activity of GC, KT-5823 inhibits PKG.