The role of hydrogen sulphide in the control of breathing in hypoxic zebrafish (<i>Danio rerio</i>)
Bibliographic record
Abstract
Key points Hydrogen sulphide (H 2 S), a gaseous neurotransmitter, is involved in oxygen sensing in glomus cells, which are oxygen‐sensing cells found in the mammalian carotid body. Neuroepithelial cells (NECs) are oxygen‐sensing cells of fish and are thought to be phylogenetic precursors of mammalian glomus cells; however, the oxygen‐sensing mechanisms of these cells remain largely unknown. Both adult and larval zebrafish responded to exogenous H 2 S by increasing ventilation in a dose‐dependent manner; H 2 S increased intracellular [Ca 2+ ] in NECs. Inhibiting endogenous H 2 S production decreased or abolished the ventilatory response to hypoxia in both adult and larval zebrafish. The results demonstrate an important role for H 2 S in oxygen sensing in zebrafish. Abstract The current study investigated the role of hydrogen sulphide (H 2 S) in oxygen sensing, intracellular signalling and promotion of ventilatory responses to hypoxia in adult and larval zebrafish ( Danio rerio ). Both larval and adult zebrafish exhibited a dose‐dependent increase in ventilation to sodium sulphide (Na 2 S), an H 2 S donor. In vertebrates, cystathionine β‐synthase (CBS) and cystathionine γ‐lyase (CSE) are enzymes that catalyse the endogenous production of H 2 S. In adult zebrafish, inhibition of both CBS and CSE with aminooxyacetate (AOA) and propargyl glycine (PPG) blunted or abolished the hypoxic hyperventilation, and the addition of Na 2 S to the water partially rescued the effects of inhibiting endogenous H 2 S production. In zebrafish larvae (4 days post‐fertilization), gene knockdown of either CBS or CSE using morpholinos attenuated the hypoxic ventilatory response. Furthermore, the intracellular calcium concentration of isolated neuroepithelial cells (NECs), which are putative oxygen chemoreceptors, increased significantly when these cells were exposed to 50 μ m Na 2 S, supporting a role for H 2 S in Ca 2+ ‐evoked neurotransmitter release in these cells. Finally, immunohistochemical labelling showed that NECs dissociated from adult gill contained CBS and CSE, whereas cutaneous NECs in larval zebrafish expressed only CSE. Taken together, these data show that H 2 S can be produced in the putative oxygen‐sensing cells of zebrafish, the NECs, in which it appears to play a pivotal role in promoting the hypoxic ventilatory response.
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 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 | 0.002 | 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 | 0.001 | 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".