A review on gastric leptin: the exocrine secretion of a gastric hormone
Bibliographic record
Abstract
A major advance in the understanding of the regulation of food intake has been the discovery of the adipokine leptin a hormone secreted by the adipose tissue. After crossing the blood-brain barrier, leptin reaches its main site of action at the level of the hypothalamic cells where it plays fundamental roles in the control of appetite and in the regulation of energy expenditure. At first considered as a hormone specific to the white adipose tissue, it was rapidly found to be expressed by other tissues. Among these, the gastric mucosa has been demonstrated to secrete large amounts of leptin. Secretion of leptin by the gastric chief cells was found to be an exocrine secretion. Leptin is secreted towards the gastric lumen into the gastric juice. We found that while secretion of leptin by the white adipose tissue is constitutive, secretion by the gastric cells is a regulated one responding very rapidly to secretory stimuli such as food intake. Exocrine-secreted leptin survives the hydrolytic conditions of the gastric juice by forming a complex with its soluble receptor. This soluble receptor is synthesized by the gastric cells and the leptin-leptin receptor complex gets formed at the level of the gastric chief cell secretory granules before being released into the gastric lumen. The leptin-leptin receptor upon resisting the hydrolytic conditions of the gastric juice is channelled, to the duodenum. Transmembrane leptin receptors expressed at the luminal membrane of the duodenal enterocytes interact with the luminal leptin. Leptin is actively transcytosed by the duodenal enterocytes. From the apical membrane it is transferred to the Golgi apparatus where it binds again its soluble receptor. The newly formed leptin-leptin receptor complex is then secreted baso-laterally into the intestinal mucosa to reach the blood capillaries and circulation thus reaching the hypothalamus where its action regulates food intake. Exocrine-secreted gastric leptin participates in the short term regulation of food intake independently from that secreted by the adipose tissue. Adipose tissue leptin on the other hand, regulates in the long term energy storage. Both tissues work in tandem to ensure management of food intake and energy expenditure.
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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 | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.001 |
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".