Effects of Pituitary Adenylate Cyclase‐Activating Polypeptide, Vasoactive Intestinal Polypeptide, and Somatostatin on the Release of Thyrotropin from the Bullfrog Pituitary
Bibliographic record
Abstract
The recent development of a specific radioimmunoassay for amphibian (bullfrog, Rana catesbeiana) thyrotropin (TSH) has made it possible to study the effects of various neuropeptides on the release of TSH from the pituitary in vitro. Up to now, corticotropin-releasing factor of bullfrog origin has been shown to have a potent TSH-releasing activity, whereas gonadotropin-releasing hormone and TSH-releasing hormone exhibit a moderate TSH-releasing effect on the adult, but not larval, pituitary. In the present study, the effects of pituitary adenylate cyclase-activating polypeptide (PACAP), vasoactive intestinal polypeptide (VIP), and somatostatin (SS) on the in vitro release of TSH from the bullfrog pituitary were investigated. Both frog (R. ridibunda) PACAP-38 and PACAP-27 caused a concentration-dependent stimulation of the release of TSH from dispersed pituitary cells during a 24-h culture. The PACAP-38- and PACAP-27-induced TSH release was suppressed by a simultaneous application of PACAP6-38. Application of high concentrations of PACAP6-38 alone caused a slight but significant stimulatory effect on the release of TSH. Frog VIP also stimulated TSH release from pituitary cells concentration-dependently. Frog SS1 (homologous to mammalian somatostatin-14) and SS2 (homologous to mammalian cortistatin) did not affect the basal release of TSH but caused a concentration-dependent suppression of the PACAP-38-induced release of TSH. These results suggest the involvement of multiple neuropeptides in the regulation of the release of TSH from the amphibian pituitary.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| 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 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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 source (direct Gemma or distilled Codex), 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".