Dihydrotestosterone‐induced relaxation of guinea pig gallbladder strips is not mediated by PKA/cAMP
Bibliographic record
Abstract
Dihydrotestosterone (DHT) is an active metabolite of testosterone (T). DHT is formed in peripheral tissues by the action of 5α-reductase. T has been shown to relax cholecystokinin octapeptide (CCK) induced tension in guinea pig gallbladder strips. This T-induced relaxation was not mediated by the PKA/cAMP second messenger system, but by other pathways. An in vitro technique using guinea pig gallbladder strips was used to determine if DHT had a different effect on CCK-induced tension than T. Statistical analysis utilized either the paired t-test or analysis of variance. DHT (0.5 μM, 1μM, 10 μM, 50 μM, and 100 μM) were used. A concentration-dependent relaxation in CCK-induced (1nM) tension was observed. When compared to the concentration-dependent relationship observed when using T, the curve was shifted to lower concentrations. The amount of relaxation induced by DHT using either 10 μM or 50 μM was significantly (p<0.01; 19.8±1.9 vs. 28.7±2.7% and 31.7±1.7 vs. 66.8±3.5%) greater than that observed using T. In order to determine if the PKA/cAMP second messenger system mediated the DHT (50 μM)-induced relaxation, PKA inhibitor 14–22 amide myristolated (PKA-IM; 180 nM) was added to the chambers. When the strips were pre-treated with PKA-IM, there was no significant difference (74.0±6.0 vs. 68.2±2.1%) in the amount of relaxation observed. 2-APB (126 μM) produced a significant (p<0.01) reduction in CCK-induced tension (0.82±0.1 vs. 0.49±0.1 g); however, there was no significant difference in the amount of relaxation (70.8±7.4 vs. 64.3±8.8 %), suggesting that inhibition of IP3 mediated Ca2+ release may cause the effect. These results suggest that the signaling pathways that mediated T-induced relaxation of CCK-induced tension also mediate the relaxation induced by DHT. The peak effect of DHT occurred at a lower concentration than T.
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 | 0.001 |
| 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 | 0.001 |
| Insufficient payload (model declined to judge) | 0.004 | 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 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".