Fig 1. Hypotonic-mediated [Ca²⁺]_i signals require Ca²⁺ influx via TRPC3 in CD cells.

(A) The average time course of [Ca²⁺]_i changes in response to 10X elevations in perfusion rate from 1.5 ml/min to 15 ml/min (high flow) and application of hypotonic medium (220 mOsm) in the absence and in the presence of a TRPV4 inhibitor, ruthenium red (RuR, 1 μM) in individual CD cells within split-opened area. The treatment times are indicated by the respective bars on the top. The number of individual experiments is shown (N = 3 mice were tested). (B) The average time course of [Ca²⁺]_i changes in response to high flow and hypotonicity in the CD cells from TRPV4 -/- mice (n–number of individual tested CD cells, N = 3 mice). (C) Summary graph of the peak amplitude of [Ca²⁺]_i responses induced by hypotonic 220 mOsm medium in the control, after pretreatment with the endoplasmic reticulum Ca²⁺ pump SERCA inhibitor thapsigargin (2 μM, 10 min), and after removing extracellular Ca²⁺ (5 mM EGTA). (D) Summary graph of the peak amplitude of [Ca²⁺]_i responses induced by hypotonic 220 mOsm medium in the control and after pretreatment with a TRPC3 channel blocker, Pyr3 (3 μM for 5 min). *—significant decrease versus 220 mOsm. N = 3 mice were used for the comparison.