Effects of Melatonin on Thyroid Physiology of Female Hamsters
Bibliographic record
Abstract
The effects of melatonin administration on thyroid physiology of female hamsters was investigated. A protocol of 25 micrograms given daily as subcutaneous injections late in the light period was found to inhibit blood levels of thyroxin (T4), triiodothyronine (T3) and thyrotropin (TSH). The free T4 index (FT4I) and the free T3 index (FT3I) were also significantly inhibited by melatonin injections. Decreasing the photoperiod under which the hamsters were kept, from 14 h light/10 h dark (14L/10D) to 10L/14D also resulted in decreased blood levels of these hormones. A protocol of melatonin injections using 2.5 mg daily, on the other hand, did not significantly inhibit blood levels of thyroid hormones or TSH; injection of this dose every afternoon into hamsters in long photoperiod significantly augmented the blood levels of T4. Continuously available melatonin in the form of subcutaneous implants of 1 mg melatonin in beeswax did not inhibit blood levels of thyroid hormones; furthermore, such implants prevented the inhibitory effects of injections of 25 micrograms melatonin. The results are consistent with the hypothesis that melatonin interferes with neurotransmitters which influence the synthesis or release of hypothalamic thyrotropin-releasing hormone.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".