Table 6.
Effects of low and high luminal calcium concentration, calcium chelator, Ca-ATPase inhibitor, and IP3 receptor antagonist on flow-induced changes in cell volume under low and high perfusion rates in mouse proximal tubules
| 5 nl/min |
20 nl/min |
|||||
|---|---|---|---|---|---|---|
| Group | n | Volumea, μm3 | n | Volumeb, μm3 | ΔVolume (Volumeb − Volumea) | ΔVolume/Volumea*100 |
| Control (1.2 mM CaCl2) | 15 | 929.4 ± 14.7 | 15 | 1,044.6 ± 41.5* | 115.2 ± 44.0 | 12.39 ± 4.46 |
| 5 mM CaCl2 | 6 | 940.8 ± 19.7NS | 6 | 890.1 ± 13.1ns† | −50.7 ± 23.7† | −5.39 ± 1.39† |
| 0 mM CaCl2+ EGTA | 6 | 888.7 ± 7.3NS | 6 | 861.8 ± 7.3*† | −26.9 ± 10.3NS | −3.03 ± 0.82† |
| BAPTA+0 mM CaCl2+ EGTA | 6 | 949.0 ± 20.7NS | 6 | 877.0 ± 8.3**† | −72,0 ± 22.3† | −7.59 ± 0.87†† |
| Thapsigargin | 6 | 925.7 ± 25.3NS | 6 | 877.0 ± 8.3ns† | −48.7 ± 26.6† | −5.26 ± 0.89† |
| 2-APB | 7 | 939.7 ± 16.7NS | 7 | 858.3 ± 13.4**†† | −81.3 ± 21.4†† | −8.66 ± 1.42†† |
Values are means ± SE; n, no. of perfused tubules. Volume formula is π*(OD/2)2*1 − π*(ID/2)2*1; 1 indicates the length or height is 1 μm; ΔVolume, the differences in volume between perfusion rate of 5 and 20 nl/min; ΔVolume/Volumea*100, percent changes in volume from low flow rate. ns, Not significantly different from low flow rates in the same group.
Significant difference from low flow rates in the same group (*P < 0.05, **P < 0.01, ***P < 0.001). NS, not significantly different compared with control at the similar flow rates.
Significant difference compared with control at the similar flow rates (†P < 0.05, ††P < 0.01, †††P < 0.001).