Table 2.
Secretion rate, [K+], and K+ flux
| Genotype | Secretion Rate, nl/min per tubule | [K+], mM | K+ Flux, pmol/min per tubule | n |
|---|---|---|---|---|
| Irk1 and Irk2 knockdown | ||||
| w;c42-GAL4/+ | 0.47 ± 0.032 | 150 ± 9.1 | 71 ± 6.5 | 13 |
| w/yw;c42-GAL4/UAS-Irk1RNAi | 0.37 ± 0.027 | 158 ± 5.9 | 58 ± 4.8 | 14 |
| w/yw;UAS-Irk1RNAi/+ | 0.38 ± 0.040 | 148 ± 11.3 | 57 ± 7.9 | 13 |
| w;UAS-Irk2RNAi/+;c42-GAL4/+ | 0.47 ± 0.070 | 147 ± 5.0 | 70 ± 11.4 | 14 |
| w;UAS-Irk2RNAi/+ | 0.59 ± 0.090 | 150 ± 8.1 | 86 ± 10.5 | 12 |
| Irk3 knockdown | ||||
| w;c42-GAL4/+ | 0.31 ± 0.035 | 147 ± 8.7 | 47 ± 6.5 | 14 |
| w/yw;c42-GAL4/UAS-Irk3RNAi | 0.32 ± 0.035 | 157 ± 8.0 | 52 ± 6.5 | 15 |
| w/yw;UAS-Irk3RNAi/+ | 0.33 ± 0.052 | 166 ± 6.6 | 56 ± 9.1 | 15 |
| Irk1/Irk3 double knockdown | ||||
| w;UAS-Irk1RNAi/+;UAS-Irk3RNAi/+ | 0.40 ± 0.042 | 164 ± 8.9 | 66 ± 7.0 | 13 |
| w;UAS-Irk1RNAi/+;c42-GAL4/UAS-Irk3RNAi | 0.34 ± 0.047 | 150 ± 12.0 | 52 ± 9.1 | 10 |
| Irk2/Irk3 double knockdown | ||||
| w;c42-GAL4/+ | 0.36 ± 0.052 | 145 ± 10.3 | 54 ± 9.3 | 10 |
| w;UAS-Irk2RNAi/+;c42-GAL4/UAS-Irk3RNAi | 0.48 ± 0.053 | 144 ± 8.8 | 70 ± 8.7 | 7 |
| w;UAS-Irk2RNAi/+;UAS-Irk3RNAi/+ | 0.41 ± 0.046 | 160 ± 12.9 | 63 ± 6.3 | 8 |
| Irk1/Irk2 double knockdown | ||||
| w;c42-GAL4/+ | 0.45 ± 0.024 | 154 ± 6.7 | 70 ± 4.0 | 42 |
| w;UAS-Irk2RNAi/+;c42-GAL4/UAS-Irk1RNAi | 0.37 ± 0.018 | 136 ± 5.6 | 53 ± 4.7 | 41 |
| w;UAS-Irk2RNAi/+;UAS-Irk1RNAi/+ | 0.49 ± 0.030 | 158 ± 3.9 | 77 ± 5.0 | 41 |
| Irk1/Irk2/Irk3 triple knockdown | ||||
| w;UAS-Irk2RNAi/+;UAS-Irk1RNAi/+ | 0.64 ± 0.051 | 166 ± 6.8 | 109 ± 9.7 | 22 |
| w;UAS-Irk2RNAi/+;c42-GAL4/UAS-Irk1RNAi | 0.38 ± 0.049 | 135 ± 14.7 | 60 ± 11.5 | 21 |
| w;UAS-Irk2RNAi/+;c42-GAL4 UAS-Irk3RNAi/UAS-Irk1RNAi | 0.47 ± 0.058 | 147 ± 11.2 | 77 ± 12.0 | 20 |
| Effect of cAMP | ||||
| w;c42-GAL4/+, vehicle | 0.33 ± 0.051 | 98 ± 6.5 | 35 ± 6.2 | 19 |
| w;c42-GAL4/+, cAMP | 0.55 ± 0.067 | 110 ± 6.5 | 64 ± 9.6 | 19 |
| w;UAS-Irk2RNAi/+;c42-GAL4/UAS-Irk1RNAi, vehicle | 0.16 ± 0.037 | 62 ± 6.2 | 11 ± 3.1 | 18 |
| w;UAS-Irk2RNAi/+;c42-GAL4/UAS-Irk1RNAi, cAMP | 0.38 ± 0.070 | 84 ± 6.7 | 37 ± 8.6 | 19 |
| Effect of ouabain | ||||
| w;c42-GAL4/+, vehicle | 0.37 ± 0.050 | 140 ± 8.9 | 56 ± 8.2 | 16 |
| w;c42-GAL4/+, ouabain | 0.27 ± 0.050 | 81 ± 7.0 | 25 ± 6.1 | 18 |
| w;UAS-Irk2RNAi/+;c42-GAL4/UAS-Irk1RNAi, vehicle | 0.29 ± 0.051 | 132 ± 12.8 | 43 ± 9.0 | 12 |
| w;UAS-Irk2RNAi/+;c42-GAL4/UAS-Irk1RNAi, ouabain | 0.16 ± 0.021 | 94 ± 6.6 | 15 ± 2.6 | 13 |
All values shown are means ± SE. Note that K+ flux was calculated separately for each tubule analyzed, and therefore the value of mean secretion rate × mean [K+] may differ slightly from measured K+ flux, attributable to rounding.