High Fat Feeding Blunts Skeletal Muscle Oxygen Mediated Blood Flow Responses in Healthy and Type 2 Diabetic Rats
Notice bibliographique
Résumé
Hypothesis: High fat diet feeding impairs microvascular blood flow responses to dynamic changes in local oxygen concentration ([O 2 ]) in Sprague-Dawley (SD) and Zucker Diabetic Sprague-Dawley (ZDSD) rats. Methods: Seven-week-old male SD and ZDSD rats were fed either a standard chow (N = 7 SD, 5 ZDSD) or a high saturated fat diet (N = 8 SD, 6 ZDSD) for 7 weeks. At 14 weeks of age animals were anaesthetized, instrumented for systemic monitoring, and mechanically ventilated. The extensor digitorum longus muscle was blunt dissected and reflected over a gas exchange chamber imbedded in the stage of an inverted microscope. Microvascular blood flow responses to high and low [O 2 ] challenges (7 – 12 %, and 7 – 2 %) and sequential changes in [O 2 ] (7 – 12 – 2 – 7 %) were recorded at baseline and during hyperinsulinemic-euglycemic clamp. Gas conditions within the chamber were set at 7 % for a 1-minute baseline followed by 2 minutes at either 2 or 12 % O 2 . The 4-minute square wave oscillation consisted of 1 minute at each [O 2 ] (7 – 12 – 2 – 7 %). Hyperinsulinemic-euglycemic clamp was achieved by simultaneous infusion of insulin (2 U/hr/kg) and variable rate of 50 % glucose until euglycemia was reached (5 - 7 mM blood glucose). Analysis of intravital videos was completed using custom MATLAB software. All animal protocols were approved by Memorial University’s Animal Care Committee. Results: Chow fed SD had significantly higher glucose infusion rates compared to high fat fed SD, chow fed ZDSD, and high fat fed ZDSD (28.11 ± 1.807 vs. 25.14 ± 1.18, 24.56 ± 2.78, 24.77 ± 2.43 mg/kg/min, p = 0.0429, 0.0305, 0.0323, respectively). Red blood cell (RBC) saturation significantly increased and decreased in all groups within 4 s following the increase and decrease in [O 2 ], respectively. Chow fed SD had significant decrease in RBC supply rate (SR) in response to 12 % [O 2 ] (10.41 ± 11.31 vs 7.44 ± 8.40 cells/s, p < 0.0001, τ = 15.85 s). In response to low [O 2 ], significant increases in SR were measured in the chow fed SD and ZDSD groups (7.10 ± 8.76 vs 11.65 ± 11.36 cells/s, p < 0.0001, τ = 17.65 s, and 10.86 ± 13.62 vs 13.86 ± 14.69 cells/s, p < 0.0001, τ = 85.74 s, respectively). High fat fed SD and ZDSD had significant increases in RBC SR during 2 % [O 2 ] (8.47 ± 9.75 vs 11.84 ± 12.11 cells/s, p < 0.0001, τ = 68.49 s, and 16.09 ± 18.12 vs 20.73 ± 21.92 cells/s, p < 0.0001, τ = 23.98 s). High fat fed ZDSD had higher, but not significantly different, baseline RBC SR compared to the chow fed ZDSD group. Chow fed SD were the only group to have an increase in RBC SR at low [O 2 ] during hyperinsulinemic-euglycemic clamp (13.80 ± 17.78 vs 18.07 ± 20.25 cells/s, p = 0.0003, τ = 10.88 s). Conclusions: High fat feeding impairs the capillary blood flow response to local increases in [O 2 ] in healthy and high fat fed T2D model rats. Chow fed ZDSD rats had slower capillary blood flow dynamics than the SD control group. Hyperinsulinemic-euglycemic clamp diminishes the O 2 mediated blood flow response in 14-week-old SD and ZDSD rats fed a high fat diet. This project was supported by the Canadian Institute of Health Research through a project grant to GMF. Studentships were supported by Memorial University's School of Graduate Studies and the Faculty of Medicine. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.
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Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».