Figure 8.

Effect of tubular flow and luminal [NaCl]_L on [Ca²⁺]_i in perimacular oscillatory cells. (A) Representative fura-2 ratio recording demonstrating the effect of elevated tubular flow from 20 to 40 nl/min (onset at the time point indicated by arrow) on the intracellular calcium dynamics in a perimacular cTAL cell located in the terminal portion of the cTAL. (B) Effect of elevations in tubular flow on the amplitude of oscillations in [Ca²⁺]_i in perimacular tubular epithelial cells. ○, Fura-2 ratio oscillation amplitude values from individual cells at different tubular flow conditions; •, average values (n = 6, one cell each from every preparation; the values in the control and high-flow groups were different from each other; P < 0.05). (C) Representative fura-2 ratio recording demonstrating the effect of an increase in [NaCl]_L and osmolality (from 20 to 80 mmol/L and from 98 to 210 mOsm/kg H₂O) on [Ca²⁺]_i in a perimacular cTAL cell located in the early portion of the DT. (D) Effect of elevations in [NaCl]_L and osmolality on [Ca²⁺]_i in perimacular tubular epithelial cells of the early DT. ○, Fura-2 ratio values from individual cells; •, average values (n = 12, one cell each from every preparation; the values in the control and high-NaCl groups were different from each other; P < 0.05).