Effects of regular physical activity on skeletal muscle structural, energetic, and microvascular properties in carriers of sickle cell trait.
To assess the effects of regular physical activity on muscle functional characteristics of carriers of sickle cell trait (SCT), 39 untrained (U) and trained (T) hemoglobin (Hb)AA (CON) and SCT subjects (U-CON, n = 12; U-SCT, n = 8; T-CON, n = 10; and T-SCT, n = 9) performed a graded exercise and a time to exhaustion (T(ex)) test, and were subjected to a muscle biopsy. Maximal power, total work performed during T(ex), citrate synthase and cytochrome c oxidase (COX) activities, respiratory chain complexes I and IV content, and capillary density (CD), diameter (COD), and surface area (CSA) were upregulated by the same proportion in T-CON and T-SCT compared with their untrained counterparts. These proportionally similar differences imply that the observed discrepancies between U-SCT and U-CON remained in the trained subjects. Specifically, both CD and COX remained and tended to remain lower, and both COD and CSA remained and tended to remain higher in T-SCT than in T-CON. Besides, carriers of SCT displayed specific adaptations with regular physical activity: creatine kinase activity; complexes II, III, and V content; and type I fiber surface area and capillary tortuosity were lower or unchanged in T-SCT than in U-SCT. In summary, our results show that 1) carriers of SCT adapted almost similarly to CON to regular physical activity for most of the studied muscle characteristics, 2) oxidative potential remains altered in physically active carriers of SCT compared with HbAA counterparts, and 3) the specific remodeling of muscle microvascular network persists in the trained state.
Université de Savoie, Laboratoire de Physiologie de l'Exercice EA4338, Chambéry, France.
Lucile
L
Vincent
Samuel
S
Oyono-Enguéllé
Léonard
L
Féasson
Viviane
V
Banimbek
Macias
M
Dohbobga
Cyril
C
Martin
Patrice
P
Thiriet
Alain
A
Francina
Hervé
H
Dubouchaud
Hervé
H
Sanchez
Rachel
R
Chapot
Christian
C
Denis
André
A
Geyssant
Laurent
L
Messonnier
D000222:Adaptation, Physiological; D000328:Adult; D001706:Biopsy; D002196:Capillaries / Q000503:physiopathology*; D002950:Citrate (si)-Synthase / Q000378:metabolism; D042967:Electron Transport Complex I / Q000378:metabolism; D003576:Electron Transport Complex IV / Q000378:metabolism; D004734:Energy Metabolism; D015444:Exercise; D005080:Exercise Test; D006441:Hemoglobin A / Q000235:genetics / Q000378:metabolism; D006451:Hemoglobin, Sickle / Q000235:genetics / Q000378:metabolism; D006579:Heterozygote; D006801:Humans; D008297:Male; D008833:Microcirculation; D009119:Muscle Contraction; D018485:Muscle Fibers, Skeletal / Q000378:metabolism / Q000473:pathology; D053580:Muscle Strength; D018482:Muscle, Skeletal / Q000098:blood supply* / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D010807:Physical Endurance; D012039:Regional Blood Flow; D057185:Sedentary Behavior; D012805:Sickle Cell Trait / Q000097:blood / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D013997:Time Factors; D055815:Young Adult
D006451:Hemoglobin, Sickle; D006441:Hemoglobin A; D003576:Electron Transport Complex IV; D002950:Citrate (si)-Synthase; D042967:Electron Transport Complex I