Serum levels of corticosterone and estradiol in rats exposed to increasing light intensities during darkness
| Light intensity (μW/cm2) . | Nude rat serum corticosterone (ng/mL) . | Nude rat serum estradiol (pg/mL) . | Buffalo rat serum corticosterone (ng/mL) . |
|---|---|---|---|
| Constant light, 345 | 196.2 ± 53.5 | 25.1 ± 11.3 | 53.25 ± 23.7 |
| 0.08 | 265.0 ± 28.17 | 19.9 ± 10.1 | 120.83 ± 19.6 |
| 0.06 | 322.7 ± 43.8 | 27.1 ± 16.8 | 105.08 ± 25.8 |
| 0.05 | 289.3 ± 41.8 | 20.3 ± 10.78 | 155.5 ± 19.1 |
| 0.02 | 266.8 ± 34.7 | 25.1 ± 5.9 | 138.75 ± 26.8 |
| Dark | 266.1 ± 34.4 | 19.3 ± 10.7 | 111.08 ± 29.5 |
| Light intensity (μW/cm2) . | Nude rat serum corticosterone (ng/mL) . | Nude rat serum estradiol (pg/mL) . | Buffalo rat serum corticosterone (ng/mL) . |
|---|---|---|---|
| Constant light, 345 | 196.2 ± 53.5 | 25.1 ± 11.3 | 53.25 ± 23.7 |
| 0.08 | 265.0 ± 28.17 | 19.9 ± 10.1 | 120.83 ± 19.6 |
| 0.06 | 322.7 ± 43.8 | 27.1 ± 16.8 | 105.08 ± 25.8 |
| 0.05 | 289.3 ± 41.8 | 20.3 ± 10.78 | 155.5 ± 19.1 |
| 0.02 | 266.8 ± 34.7 | 25.1 ± 5.9 | 138.75 ± 26.8 |
| Dark | 266.1 ± 34.4 | 19.3 ± 10.7 | 111.08 ± 29.5 |
NOTE: See Figs. 3 and 4 legends for further details. Blood samples were taken during the middle of the true dark or subjective dark phase. Mean serum hormone (±SE); n = 6 rats per group. There were no significant differences in hormone levels among any of the groups exposed to different light intensities.