Increased expression of Giα proteins in L-NAME-induced hypertension is reversed by losartan: implication of AT1 angiotensin receptor
Bibliographic record
Abstract
We have previously reported that N-ω-nitro-L-arginine-methyl ester (L-NAME)-induced hypertensive rats exhibited an enhanced expression of Gi proteins. In addition, losartan, AT1 receptor antagonist, has been shown to decrease L-NAME-induced increase in the blood pressure. The present study was designed to evaluate the involvement of AT1 receptor in L-NAME-induced alterations in blood pressure and G-protein adenylyl cyclase signaling pathway. L-NAME (70 mg/kg body weight), Losartan (10 mg/kg b.wt) alone or in combination were given orally for 4 weeks. Control group received only plain tap water. The expression of Giα-2 and Giα-3 proteins and mRNA was enhanced in L-NAME-treated rats which was reversed by losartan treatment. However, losartan alone did not alter the levels of Gi-α proteins or mRNA. On the other hand, the expression of Gsα was not altered by these treatments. Guanosine 5'-o-(3-thiophosphate) (GTPγS)- stimulated adenylyl cyclase activity in both control and L-NAME-treated groups, but the extent of stimulation was significantly attenuated in L-NAME-treated rats, which was reversed by losartan. Similarly, stimulation of adenylyl cyclase exerted by isoproterenol, 5'-N-ethylcarboxamideadenosine (NECA) glucagon, forskolin and sodium fluoride were diminished in L-NAME-treated rats and were reversed by losartan treatment. On the other hand, inhibition of forskolin-stimulated enzyme activity by low concentrations of GTPγS that was significantly enhanced in L-NAME- treated rats, was attenuated by losartan. In addition, oxotremorine- and angiotensin II-mediated inhibiton of adenylyl cyclase activity was completely attenuated in L-NAME-treated rats which was reversed by losartan. These results suggest the implication of AT1 receptor in L-NAME-induced enhanced expression of Giα proteins and hypertension. (Supported by grant from Medical Research Council of Canada)
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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 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 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".