Effects of arginine vasopressin (AVP) deficiency on long term arterial blood pressure in normal and spontaneously hypertensive rats (SHR)
Bibliographic record
Abstract
The role of AVP controlling the arterial blood pressure (BP) in basal conditions remains unclear. Previously, we described that neurointermediate pituitary lobectomy (NIL) in rats, induced an early but transient diabetes insipidus and permanent low mean BP (MBP), without changes in aldosterone, Na and K serum levels (1). In order to obtain a deeper insight in the temporal relationship between NIL and MBP, here we evaluated the effects of NIL on AVP and oxytocin (OT) serum levels and MBP from time 0 to 6 hours and at 3, 15, 45 and 90 days post NIL. Water intake and urine output, urine sodium and potassium concentrations and sodium and potassium serum levels, were measured at these same times, whereas the renin‐angiotensin II‐aldosterone system (RAAS) was assessed at 3 and 45 days post NIL. All values were compared with the respective sham operated (SHAM) groups. Values are expressed as mean ± SEM. Results NIL caused significant and permanent low AVP and OT serum levels (10.6 ± 0.8 versus (vs) 2.4 ± 0.16 (pg/ml), SHAM vs NIL respectively), transient diabetes insipidus of 15–30 days of duration and a significant and permanent decrease of the MBP in 70% of the NIL animals (106.8 ± 3.15 vs 73.8 ± 3.2 mmHg respectively). Hypotension was apparent 30 minutes after NIL. Indirect systolic blood pressure (SBP) (cuff tail) were measured in SHR and NIL‐SHR rats at 15 and 3 days before and 8, 20, 35 and 45 days after surgeries. In all times SBP was significantly decrease in NIL animals. The last measured was 166.5 ± 16.8 vs 121.4 ± 12.16 mmHg, SHR vs NIL‐SHR). As in previously studies, no significant differences in the RAAS and serum electrolytes were evident, whereas urine electrolytes were lower in NIL rats (Na; 33.08 ± 6.177 vs 58.99 ± 15.061 and K; 67.148 ± 12.515 vs 126.9 ± 26.97 respectively). We concluded that: 1) the permanent deficiency of AVP (NIL animals) is responsible of the long‐term low BP levels. 2) At the present we suppose that in NIL animals, the normal Na and K serum levels are due to the remnant basal concentrations of AVP (2.4 ± 0.16) which well may be enough to maintain the hydro‐electrolytic balance in the body fluids. 3) The decreased Na and K levels in the urine of the NIL animals may be explained partially for the kidney adaptations of the several segments of the nephron to the low levels of AVP. 4) Further studies are needed to explain why 30% of the NIL animals did not develop hypotension, and to explain how heart, blood vessels and kidney mechanisms adapt to these new physiological conditions. Support or Funding Information Supported by UAA‐PIFF 14‐1 and CONACYT‐221262 grants (AQS) and CONACYT (GMV) PhD scholarship, México, and the Jarislowsky and Lloyd Carr‐Harris Foundations.
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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 | 0.001 |
| 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".