A Novel Amphibian Hypothalamic Neuropeptide: Isolation, Localization, and Biological Activity
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
Neuropeptides similar to the molluscan cardioexcitatory Phe-Met-Arg-Phe-NH2 have been identified in several vertebrates and characterized by the RFa motif at their C terminus (RFa peptides). In this study, we sought to identify an amphibian hypothalamic RFa peptide that may regulate secretion of hormones by the anterior pituitary gland. An acid extract of bullfrog hypothalami was passed through C-18 reversed-phase cartridges, and then the retained material was subjected to HPLC, initially using a C-18 reversed-phase column. RFa immunoreactivity was measured in the eluted fractions by a dot immunoblot assay employing an antiserum raised against RFa. Immunoreactive fractions were subjected to further cation exchange and reversed-phase HPLC purification. The isolated peptide was a novel RFa peptide and shown to have the sequence Ser-Leu-Lys-Pro-Ala-Ala-Asn-Leu-Pro-Leu-Arg-Phe-NH2. The cell bodies and terminals containing this peptide were localized immunohistochemically in the suprachiasmatic nucleus and median eminence, respectively. This RFa peptide stimulated, in a dose-related way, the release of GH from cultured pituitary cells, its threshold concentration ranging between 10(-9) and 10(-8) M. This peptide did not have any appreciable effect on the secretion of PRL and gonadotropins. It was ascertained that the peptide was also effective in elevating the circulating GH level when administered systemically. Thus, the amphibian hypothalamus was revealed to contain a novel functional RFa peptide that stimulates GH release. This peptide was designated frog GH-releasing peptide.
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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 | 0.001 |
| 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 | 0.000 |
| 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 it